1. Added JNI

2. Added YSCB basic code
3. Added future for client
4. Added properties in client

code/cppclient/Makefile

@@ -45,9 +45,10 @@ count:
 
 
 Jclient: $(OBJS)
-	$(CXX) -o libHelloImpl.so -shared .build/Hello.o $(LIBS)
+	$(CXX) -o libhpdosclient.so -L/usr/local/lib -shared $^  $(LIBS)
 	@echo "jclient "$<" successfully!"
-
+	sudo cp libhpdosclient.so /usr/lib
+	@echo "Copied libhpdosclient.so to /usr/lib"
 #jcompile: javac $(JSRCS) -d JBUILD
 
 JniHeader:

code/cppclient/Readme.md

+Steps to build jni client
+> make JniHeader <br>
+> make JClient <br>
+> java -cp jsrc JClient
+
+Running YSCB 
+> mvn compile <br>
+
+./bin/ycsb load hpdos -P workloads/workloadb -threads 1
+mvn -pl site.ycsb:hpdos-binding -am clean package -Dcheckstyle.skip 
+
+
+to do 
+delete client endpoint on close
+threading in client and hashing in client
+
+resolve double delete for get and put
+add cache add support for invalidation
+
+interface client API through endpointGroup
+Endpointgroup to manage list of servers and caches, Invalidation 
+
+./bin/ycsb shell hpdos
+./bin/ycsb run hpdos -P workloads/workloada
+./bin/ycsb load hpdos -P workloads/workloada
+Options:
+    -P file        Specify workload file
+    -cp path       Additional Java classpath entries
+    -jvm-args args Additional arguments to the JVM
+    -p key=value   Override workload property
+    -s             Print status to stderr
+    -target n      Target ops/sec (default: unthrottled)
+    -threads n     Number of client threads (default: 1)
\ No newline at end of file

code/cppclient/YCSB/.editorconfig

+# Copyright (c) 2015, 2017 YCSB contributors.
+# All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you
+# may not use this file except in compliance with the License. You
+# may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# permissions and limitations under the License. See accompanying
+# LICENSE file.
+# For more info, see: http://EditorConfig.org
+root = true
+
+[*.java]
+indent_style = space
+indent_size = 2
+continuation_indent_size = 4
+
+[*.md]
+indent_style = space
+indent_size = 2
+continuation_indent_size = 4
+
+[*.xml]
+indent_style = space
+indent_size = 2
+continuation_indent_size = 4

code/cppclient/YCSB/.gitignore

+# ignore compiled byte code
+target
+
+# ignore output files from testing
+output*
+
+# ignore standard Eclipse files
+.project
+.classpath
+.settings
+.checkstyle
+
+# ignore standard IntelliJ files
+.idea/
+*.iml
+*.ipr
+*.iws
+
+# ignore standard Vim and Emacs temp files
+*.swp
+*~
+
+# ignore standard Mac OS X files/dirs
+.DS_Store
+/differentbin/

code/cppclient/YCSB/.travis.yml

+# Copyright (c) 2010 Yahoo! Inc., 2012 - 2015 YCSB contributors. 
+# All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License"); you
+# may not use this file except in compliance with the License. You
+# may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+# implied. See the License for the specific language governing
+# permissions and limitations under the License. See accompanying
+# LICENSE file.
+
+# more info here about TravisCI and Java projects
+# http://docs.travis-ci.com/user/languages/java/
+
+language: java
+
+jdk:
+  - openjdk8
+  - openjdk11
+  - oraclejdk11
+
+addons:
+  hosts:
+    - myshorthost
+  hostname: myshorthost
+  postgresql: "9.5"
+
+install:
+  - mvn -N io.takari:maven:0.7.7:wrapper -Dmaven=3.6.3
+  - ./mvnw install -q -DskipTests=true
+
+script: ./mvnw test -q
+
+before_script:
+  - psql -c 'CREATE database test;' -U postgres
+  - psql -c 'CREATE TABLE usertable (YCSB_KEY VARCHAR(255) PRIMARY KEY not NULL, YCSB_VALUE JSONB not NULL);' -U postgres -d test
+  - psql -c 'GRANT ALL PRIVILEGES ON DATABASE test to postgres;' -U postgres
+
+# Services to start for tests.
+services:
+  - ignite
+  - mongodb
+  - postgresql
+# temporarily disable riak. failing, docs offline.
+#  - riak
+
+# Can't use container based infra because of hosts/hostname
+sudo: true

code/cppclient/YCSB/NOTICE.txt

+=========================================================================
+NOTICE file for use with, and corresponding to Section 4 of,            
+the Apache License, Version 2.0,                                  
+in this case for the YCSB project.                     
+=========================================================================
+
+   This product includes software developed by
+   Yahoo! Inc. (www.yahoo.com)
+   Copyright (c) 2010 Yahoo! Inc.  All rights reserved.
+
+   This product includes software developed by
+   Google Inc. (www.google.com)
+   Copyright (c) 2015 Google Inc.  All rights reserved.

code/cppclient/YCSB/README.md

+<!--
+Copyright (c) 2010 Yahoo! Inc., 2012 - 2016 YCSB contributors.
+All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+YCSB
+====================================
+[![Build Status](https://travis-ci.org/brianfrankcooper/YCSB.png?branch=master)](https://travis-ci.org/brianfrankcooper/YCSB)
+
+
+
+Links
+-----
+* To get here, use https://ycsb.site
+* [Our project docs](https://github.com/brianfrankcooper/YCSB/wiki)
+* [The original announcement from Yahoo!](https://labs.yahoo.com/news/yahoo-cloud-serving-benchmark/)
+
+Getting Started
+---------------
+
+1. Download the [latest release of YCSB](https://github.com/brianfrankcooper/YCSB/releases/latest):
+
+    ```sh
+    curl -O --location https://github.com/brianfrankcooper/YCSB/releases/download/0.17.0/ycsb-0.17.0.tar.gz
+    tar xfvz ycsb-0.17.0.tar.gz
+    cd ycsb-0.17.0
+    ```
+    
+2. Set up a database to benchmark. There is a README file under each binding 
+   directory.
+
+3. Run YCSB command. 
+
+    On Linux:
+    ```sh
+    bin/ycsb.sh load basic -P workloads/workloada
+    bin/ycsb.sh run basic -P workloads/workloada
+    ```
+
+    On Windows:
+    ```bat
+    bin/ycsb.bat load basic -P workloads\workloada
+    bin/ycsb.bat run basic -P workloads\workloada
+    ```
+
+  Running the `ycsb` command without any argument will print the usage. 
+   
+  See https://github.com/brianfrankcooper/YCSB/wiki/Running-a-Workload
+  for a detailed documentation on how to run a workload.
+
+  See https://github.com/brianfrankcooper/YCSB/wiki/Core-Properties for 
+  the list of available workload properties.
+
+
+Building from source
+--------------------
+
+YCSB requires the use of Maven 3; if you use Maven 2, you may see [errors
+such as these](https://github.com/brianfrankcooper/YCSB/issues/406).
+
+To build the full distribution, with all database bindings:
+
+    mvn clean package
+
+To build a single database binding:
+
+    mvn -pl site.ycsb:mongodb-binding -am clean package

code/cppclient/YCSB/binding-parent/datastore-specific-descriptor/pom.xml

+<!-- 
+Copyright (c) 2015 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>site.ycsb</groupId>
+    <artifactId>root</artifactId>
+    <version>0.18.0-SNAPSHOT</version>
+    <relativePath>../../</relativePath>
+  </parent>
+
+  <artifactId>datastore-specific-descriptor</artifactId>
+  <name>Per Datastore Binding descriptor</name>
+  <packaging>jar</packaging>
+
+  <description>
+    This module contains the assembly descriptor used by the individual components
+    to build binding-specific distributions.
+  </description>
+  <dependencies>
+    <dependency>
+      <groupId>site.ycsb</groupId>
+      <artifactId>core</artifactId>
+      <version>${project.version}</version>
+    </dependency>
+  </dependencies>
+</project>
+

code/cppclient/YCSB/binding-parent/datastore-specific-descriptor/src/main/resources/assemblies/datastore-specific-assembly.xml

+<!-- 
+Copyright (c) 2015 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+<assembly xmlns="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/plugins/maven-assembly-plugin/assembly/1.1.2 http://maven.apache.org/xsd/assembly-1.1.2.xsd">
+  <id>dist</id>
+  <includeBaseDirectory>true</includeBaseDirectory>
+  <baseDirectory>ycsb-${artifactId}-${version}</baseDirectory>
+  <files>
+    <file>
+      <source>README.md</source>
+      <outputDirectory></outputDirectory>
+    </file>
+  </files>
+  <fileSets>
+    <fileSet>
+      <directory>..</directory>
+      <outputDirectory></outputDirectory>
+      <fileMode>0644</fileMode>
+      <includes>
+        <include>LICENSE.txt</include>
+        <include>NOTICE.txt</include>
+      </includes>
+    </fileSet>
+    <fileSet>
+      <directory>../bin</directory>
+      <outputDirectory>bin</outputDirectory>
+      <fileMode>0755</fileMode>
+      <includes>
+        <include>ycsb*</include>
+      </includes>
+    </fileSet>
+    <fileSet>
+      <directory>../bin</directory>
+      <outputDirectory>bin</outputDirectory>
+      <fileMode>0644</fileMode>
+      <includes>
+        <include>bindings.properties</include>
+      </includes>
+    </fileSet>
+    <fileSet>
+      <directory>../workloads</directory>
+      <outputDirectory>workloads</outputDirectory>
+      <fileMode>0644</fileMode>
+    </fileSet>
+    <fileSet>
+      <directory>src/main/conf</directory>
+      <outputDirectory>conf</outputDirectory>
+      <fileMode>0644</fileMode>
+    </fileSet>
+  </fileSets>
+  <dependencySets>
+    <dependencySet>
+      <outputDirectory>lib</outputDirectory>
+      <includes>
+        <include>site.ycsb:core</include>
+      </includes>
+      <scope>provided</scope>
+      <useTransitiveFiltering>true</useTransitiveFiltering>
+    </dependencySet>
+    <dependencySet>
+      <outputDirectory>lib</outputDirectory>
+      <includes>
+        <include>*:jar:*</include>
+      </includes>
+      <excludes>
+        <exclude>*:sources</exclude>
+      </excludes>
+    </dependencySet>
+  </dependencySets>
+</assembly>

code/cppclient/YCSB/binding-parent/pom.xml

+<!-- 
+Copyright (c) 2015-2016 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <parent>
+    <groupId>site.ycsb</groupId>
+    <artifactId>root</artifactId>
+    <version>0.18.0-SNAPSHOT</version>
+  </parent>
+
+  <artifactId>binding-parent</artifactId>
+  <name>YCSB Datastore Binding Parent</name>
+  <packaging>pom</packaging>
+
+  <description>
+    This module acts as the parent for new datastore bindings.
+    It creates a datastore specific binary artifact.
+  </description>
+
+  <modules>
+    <module>datastore-specific-descriptor</module>
+  </modules>
+
+  <properties>
+    <!-- See the test-on-jdk9 profile below. Default to 'jdk9 works' -->
+    <skipJDK9Tests>false</skipJDK9Tests>
+    <skipJDK10Tests>false</skipJDK10Tests>
+    <skipJDK11Tests>false</skipJDK11Tests>
+  </properties>
+
+  <build>
+    <pluginManagement>
+      <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-assembly-plugin</artifactId>
+          <version>${maven.assembly.version}</version>
+          <dependencies>
+            <dependency>
+              <groupId>site.ycsb</groupId>
+              <artifactId>datastore-specific-descriptor</artifactId>
+              <version>${project.version}</version>
+            </dependency>
+          </dependencies>
+          <configuration>
+            <descriptorRefs>
+              <descriptorRef>datastore-specific-assembly</descriptorRef>
+            </descriptorRefs>
+            <finalName>ycsb-${project.artifactId}-${project.version}</finalName>
+            <formats>
+              <format>tar.gz</format>
+            </formats>
+            <appendAssemblyId>false</appendAssemblyId>
+            <tarLongFileMode>posix</tarLongFileMode>
+          </configuration>
+          <executions>
+            <execution>
+              <phase>package</phase>
+              <goals>
+                <goal>single</goal>
+              </goals>
+            </execution>
+          </executions>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-checkstyle-plugin</artifactId>
+          <executions>
+            <execution>
+              <id>validate</id>
+              <configuration>
+                <configLocation>../checkstyle.xml</configLocation>
+              </configuration>
+            </execution>
+          </executions>
+        </plugin>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-dependency-plugin</artifactId>
+          <version>${maven.dependency.version}</version>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+    <plugins>
+        <plugin>
+          <groupId>org.apache.maven.plugins</groupId>
+          <artifactId>maven-dependency-plugin</artifactId>
+          <executions>
+            <execution>
+              <id>stage-dependencies</id>
+              <phase>package</phase>
+              <goals>
+                <goal>copy-dependencies</goal>
+               </goals>
+               <configuration>
+                 <includeScope>runtime</includeScope>
+               </configuration>
+            </execution>
+          </executions>
+        </plugin>
+    </plugins>
+  </build>
+  <profiles>
+    <!-- If the binding defines a README, presume we should make an assembly. -->
+    <profile>
+      <id>datastore-binding</id>
+      <activation>
+        <file>
+          <exists>README.md</exists>
+        </file>
+      </activation>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-assembly-plugin</artifactId>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+    <!-- If the binding doesn't work with jdk9, it should redefine the
+         skipJDK9 property
+      -->
+    <profile>
+      <id>tests-on-jdk9</id>
+      <activation>
+        <jdk>9</jdk>
+      </activation>
+      <properties>
+        <skipTests>${skipJDK9Tests}</skipTests>
+      </properties>
+    </profile>
+    <!-- If the binding doesn't work with jdk10, it should redefine the
+         skipJDK10 property
+      -->
+    <profile>
+      <id>tests-on-jdk10</id>
+      <activation>
+        <jdk>10</jdk>
+      </activation>
+      <properties>
+        <skipTests>${skipJDK10Tests}</skipTests>
+      </properties>
+    </profile>
+    <!-- If the binding doesn't work with jdk11, it should redefine the
+         skipJDK11 property
+      -->
+    <profile>
+      <id>tests-on-jdk11</id>
+      <activation>
+        <jdk>11</jdk>
+      </activation>
+      <properties>
+        <skipTests>${skipJDK11Tests}</skipTests>
+      </properties>
+    </profile>
+    <!-- When doing a YCSB release, we want to make sure specific bindings aren't included in the maven repo -->
+    <profile>
+      <id>ycsb-release</id>
+      <properties>
+        <!-- Set the deploy plugin to skip wherever this property is inherited -->
+        <maven.deploy.skip>true</maven.deploy.skip>
+      </properties>
+      <build>
+        <plugins>
+          <!-- We still want to make sure that *this* module gets deployed. -->
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-deploy-plugin</artifactId>
+            <executions>
+              <execution>
+                <id>but-still-deploy-the-binding-parent</id>
+                <goals>
+                  <goal>deploy</goal>
+                </goals>
+                <phase>deploy</phase>
+                <inherited>false</inherited>
+                <configuration>
+                  <skip>false</skip>
+                </configuration>
+              </execution>
+            </executions>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
+</project>
+

code/cppclient/YCSB/cassandra/README.md

+<!--
+Copyright (c) 2015 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+# Apache Cassandra 2.x CQL binding
+
+Binding for [Apache Cassandra](http://cassandra.apache.org), using the CQL API
+via the [DataStax
+driver](http://docs.datastax.com/en/developer/java-driver/2.1/java-driver/whatsNew2.html).
+
+To run against the (deprecated) Cassandra Thrift API, use the `cassandra-10` binding.
+
+## Creating a table for use with YCSB
+
+For keyspace `ycsb`, table `usertable`:
+
+    cqlsh> create keyspace ycsb
+        WITH REPLICATION = {'class' : 'SimpleStrategy', 'replication_factor': 3 };
+    cqlsh> USE ycsb;
+    cqlsh> create table usertable (
+        y_id varchar primary key,
+        field0 varchar,
+        field1 varchar,
+        field2 varchar,
+        field3 varchar,
+        field4 varchar,
+        field5 varchar,
+        field6 varchar,
+        field7 varchar,
+        field8 varchar,
+        field9 varchar);
+
+**Note that `replication_factor` and consistency levels (below) will affect performance.**
+
+## Cassandra Configuration Parameters
+
+- `hosts` (**required**)
+  - Cassandra nodes to connect to.
+  - No default.
+
+* `port`
+  * CQL port for communicating with Cassandra cluster.
+  * Default is `9042`.
+
+- `cassandra.keyspace`
+  Keyspace name - must match the keyspace for the table created (see above).
+  See http://docs.datastax.com/en/cql/3.1/cql/cql_reference/create_keyspace_r.html for details.
+
+  - Default value is `ycsb`
+
+- `cassandra.username`
+- `cassandra.password`
+  - Optional user name and password for authentication. See http://docs.datastax.com/en/cassandra/2.0/cassandra/security/security_config_native_authenticate_t.html for details.
+
+* `cassandra.readconsistencylevel`
+* `cassandra.writeconsistencylevel`
+
+  * Default value is `QUORUM`
+  - Consistency level for reads and writes, respectively. See the [DataStax documentation](http://docs.datastax.com/en/cassandra/2.0/cassandra/dml/dml_config_consistency_c.html) for details.
+
+* `cassandra.maxconnections`
+* `cassandra.coreconnections`
+  * Defaults for max and core connections can be found here: https://datastax.github.io/java-driver/2.1.8/features/pooling/#pool-size. Cassandra 2.0.X falls under protocol V2, Cassandra 2.1+ falls under protocol V3.
+* `cassandra.connecttimeoutmillis`
+* `cassandra.useSSL`
+  * Default value is false.
+  - To connect with SSL set this value to true.
+* `cassandra.readtimeoutmillis`
+  * Defaults for connect and read timeouts can be found here: https://docs.datastax.com/en/drivers/java/2.0/com/datastax/driver/core/SocketOptions.html.
+* `cassandra.tracing`
+  * Default is false
+  * https://docs.datastax.com/en/cql/3.3/cql/cql_reference/tracing_r.html

code/cppclient/YCSB/cassandra/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+
+<!--
+Copyright (c) 2012-2016 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>site.ycsb</groupId>
+    <artifactId>binding-parent</artifactId>
+    <version>0.18.0-SNAPSHOT</version>
+    <relativePath>../binding-parent</relativePath>
+  </parent>
+
+  <artifactId>cassandra-binding</artifactId>
+  <name>Cassandra 2.1+ DB Binding</name>
+  <packaging>jar</packaging>
+
+  <properties>
+    <!-- Skip tests by default. will be activated by jdk8 profile -->
+    <skipTests>true</skipTests>
+  </properties>
+
+  <dependencies>
+    <!-- CQL driver -->
+    <dependency>
+      <groupId>com.datastax.cassandra</groupId>
+      <artifactId>cassandra-driver-core</artifactId>
+      <version>${cassandra.cql.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>site.ycsb</groupId>
+      <artifactId>core</artifactId>
+      <version>${project.version}</version>
+      <scope>provided</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.cassandraunit</groupId>
+      <artifactId>cassandra-unit</artifactId>
+      <version>3.0.0.1</version>
+      <classifier>shaded</classifier>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.slf4j</groupId>
+      <artifactId>slf4j-simple</artifactId>
+      <version>1.7.21</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>4.12</version>
+      <scope>test</scope>
+    </dependency>
+    <!-- only for Cassandra test (Cassandra 2.2+ uses Sigar for collecting system information, and Sigar requires some native lib files) -->
+	  <dependency>
+	    <groupId>org.hyperic</groupId>
+	    <artifactId>sigar-dist</artifactId>
+	    <version>1.6.4.129</version>
+	    <type>zip</type>
+	    <scope>test</scope>
+	  </dependency>
+  </dependencies>
+
+  <profiles>
+    <!-- Cassandra 2.2+ requires JDK8 to run, so none of our tests
+         will work unless we're using jdk8.
+      -->
+    <profile>
+      <id>jdk8-tests</id>
+      <activation>
+        <jdk>1.8</jdk>
+      </activation>
+      <properties>
+        <skipTests>false</skipTests>
+      </properties>
+    </profile>
+  </profiles>
+  <!-- sigar-dist can be downloaded from jboss repository -->
+	<repositories>
+		<repository>
+			<id>central2</id>
+			<name>sigar Repository</name>
+			<url>https://repository.jboss.org/nexus/content/groups/public-jboss/</url>
+			<layout>default</layout>
+			<snapshots>
+				<enabled>false</enabled>
+			</snapshots>
+		</repository>
+	</repositories>
+	<!-- unzip sigar-dist/lib files. 
+		References: 
+		http://stackoverflow.com/questions/5388661/unzip-dependency-in-maven 
+		https://arviarya.wordpress.com/2013/09/22/sigar-access-operating-system-and-hardware-level-information/
+	 -->
+ 	<build>
+	 	<plugins>
+	 		<plugin>
+			    <groupId>org.apache.maven.plugins</groupId>
+			    <artifactId>maven-dependency-plugin</artifactId>
+			    <executions>
+			      <execution>
+			        <id>unpack-sigar</id>
+			        <phase>process-test-resources<!-- or any other valid maven phase --></phase>
+			        <goals>
+			          <goal>unpack-dependencies</goal>
+			        </goals>
+			        <configuration>
+			          <includeGroupIds>org.hyperic</includeGroupIds>
+			          <includeArtifactIds>sigar-dist</includeArtifactIds>
+			          <includes>**/sigar-bin/lib/*</includes>
+					  <excludes>**/sigar-bin/lib/*jar</excludes>
+			          <outputDirectory>
+			             ${project.build.directory}/cassandra-dependency
+			          </outputDirectory>
+			        </configuration>
+			      </execution>
+			    </executions>
+			</plugin>
+			<plugin>
+			  <groupId>org.apache.maven.plugins</groupId>
+			  <artifactId>maven-surefire-plugin</artifactId>
+			  <version>2.8</version>
+			  <configuration>
+			    <argLine>-Djava.library.path=${project.build.directory}/cassandra-dependency/hyperic-sigar-1.6.4/sigar-bin/lib</argLine>
+			  </configuration>
+			</plugin>
+			
+	 	</plugins>
+ 	</build>
+</project>

code/cppclient/YCSB/cassandra/src/main/java/site/ycsb/db/package-info.java

+/*
+ * Copyright (c) 2014, Yahoo!, Inc. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+/**
+ * The YCSB binding for <a href="http://cassandra.apache.org/">Cassandra</a> 
+ * 2.1+ via CQL.
+ */
+package site.ycsb.db;
+

code/cppclient/YCSB/cassandra/src/test/java/site/ycsb/db/CassandraCQLClientTest.java

+/**
+ * Copyright (c) 2015 YCSB contributors All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+package site.ycsb.db;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.hasEntry;
+import static org.hamcrest.Matchers.hasSize;
+import static org.hamcrest.Matchers.is;
+import static org.hamcrest.Matchers.notNullValue;
+import static org.hamcrest.Matchers.nullValue;
+
+import com.google.common.collect.Sets;
+
+import com.datastax.driver.core.ResultSet;
+import com.datastax.driver.core.Row;
+import com.datastax.driver.core.Session;
+import com.datastax.driver.core.Statement;
+import com.datastax.driver.core.querybuilder.Insert;
+import com.datastax.driver.core.querybuilder.QueryBuilder;
+import com.datastax.driver.core.querybuilder.Select;
+import site.ycsb.ByteIterator;
+import site.ycsb.Status;
+import site.ycsb.StringByteIterator;
+import site.ycsb.measurements.Measurements;
+import site.ycsb.workloads.CoreWorkload;
+
+import org.cassandraunit.CassandraCQLUnit;
+import org.cassandraunit.dataset.cql.ClassPathCQLDataSet;
+import org.junit.After;
+import org.junit.Before;
+import org.junit.ClassRule;
+import org.junit.Test;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+
+/**
+ * Integration tests for the Cassandra client
+ */
+public class CassandraCQLClientTest {
+  // Change the default Cassandra timeout from 10s to 120s for slow CI machines
+  private final static long timeout = 120000L;
+
+  private final static String TABLE = "usertable";
+  private final static String HOST = "localhost";
+  private final static int PORT = 9142;
+  private final static String DEFAULT_ROW_KEY = "user1";
+
+  private CassandraCQLClient client;
+  private Session session;
+
+  @ClassRule
+  public static CassandraCQLUnit cassandraUnit = new CassandraCQLUnit(
+    new ClassPathCQLDataSet("ycsb.cql", "ycsb"), null, timeout);
+
+  @Before
+  public void setUp() throws Exception {
+    session = cassandraUnit.getSession();
+
+    Properties p = new Properties();
+    p.setProperty("hosts", HOST);
+    p.setProperty("port", Integer.toString(PORT));
+    p.setProperty("table", TABLE);
+
+    Measurements.setProperties(p);
+    final CoreWorkload workload = new CoreWorkload();
+    workload.init(p);
+    client = new CassandraCQLClient();
+    client.setProperties(p);
+    client.init();
+  }
+
+  @After
+  public void tearDownClient() throws Exception {
+    if (client != null) {
+      client.cleanup();
+    }
+    client = null;
+  }
+
+  @After
+  public void clearTable() throws Exception {
+    // Clear the table so that each test starts fresh.
+    final Statement truncate = QueryBuilder.truncate(TABLE);
+    if (cassandraUnit != null) {
+      cassandraUnit.getSession().execute(truncate);
+    }
+  }
+
+  @Test
+  public void testReadMissingRow() throws Exception {
+    final HashMap<String, ByteIterator> result = new HashMap<String, ByteIterator>();
+    final Status status = client.read(TABLE, "Missing row", null, result);
+    assertThat(result.size(), is(0));
+    assertThat(status, is(Status.NOT_FOUND));
+  }
+
+  private void insertRow() {
+    final String rowKey = DEFAULT_ROW_KEY;
+    Insert insertStmt = QueryBuilder.insertInto(TABLE);
+    insertStmt.value(CassandraCQLClient.YCSB_KEY, rowKey);
+
+    insertStmt.value("field0", "value1");
+    insertStmt.value("field1", "value2");
+    session.execute(insertStmt);
+  }
+
+  @Test
+  public void testRead() throws Exception {
+    insertRow();
+
+    final HashMap<String, ByteIterator> result = new HashMap<String, ByteIterator>();
+    final Status status = client.read(TABLE, DEFAULT_ROW_KEY, null, result);
+    assertThat(status, is(Status.OK));
+    assertThat(result.entrySet(), hasSize(11));
+    assertThat(result, hasEntry("field2", null));
+
+    final HashMap<String, String> strResult = new HashMap<String, String>();
+    for (final Map.Entry<String, ByteIterator> e : result.entrySet()) {
+      if (e.getValue() != null) {
+        strResult.put(e.getKey(), e.getValue().toString());
+      }
+    }
+    assertThat(strResult, hasEntry(CassandraCQLClient.YCSB_KEY, DEFAULT_ROW_KEY));
+    assertThat(strResult, hasEntry("field0", "value1"));
+    assertThat(strResult, hasEntry("field1", "value2"));
+  }
+
+  @Test
+  public void testReadSingleColumn() throws Exception {
+    insertRow();
+    final HashMap<String, ByteIterator> result = new HashMap<String, ByteIterator>();
+    final Set<String> fields = Sets.newHashSet("field1");
+    final Status status = client.read(TABLE, DEFAULT_ROW_KEY, fields, result);
+    assertThat(status, is(Status.OK));
+    assertThat(result.entrySet(), hasSize(1));
+    final Map<String, String> strResult = StringByteIterator.getStringMap(result);
+    assertThat(strResult, hasEntry("field1", "value2"));
+  }
+
+  @Test
+  public void testInsert() throws Exception {
+    final String key = "key";
+    final Map<String, String> input = new HashMap<String, String>();
+    input.put("field0", "value1");
+    input.put("field1", "value2");
+
+    final Status status = client.insert(TABLE, key, StringByteIterator.getByteIteratorMap(input));
+    assertThat(status, is(Status.OK));
+
+    // Verify result
+    final Select selectStmt =
+        QueryBuilder.select("field0", "field1")
+            .from(TABLE)
+            .where(QueryBuilder.eq(CassandraCQLClient.YCSB_KEY, key))
+            .limit(1);
+
+    final ResultSet rs = session.execute(selectStmt);
+    final Row row = rs.one();
+    assertThat(row, notNullValue());
+    assertThat(rs.isExhausted(), is(true));
+    assertThat(row.getString("field0"), is("value1"));
+    assertThat(row.getString("field1"), is("value2"));
+  }
+
+  @Test
+  public void testUpdate() throws Exception {
+    insertRow();
+    final Map<String, String> input = new HashMap<String, String>();
+    input.put("field0", "new-value1");
+    input.put("field1", "new-value2");
+
+    final Status status = client.update(TABLE,
+                                        DEFAULT_ROW_KEY,
+                                        StringByteIterator.getByteIteratorMap(input));
+    assertThat(status, is(Status.OK));
+
+    // Verify result
+    final Select selectStmt =
+        QueryBuilder.select("field0", "field1")
+            .from(TABLE)
+            .where(QueryBuilder.eq(CassandraCQLClient.YCSB_KEY, DEFAULT_ROW_KEY))
+            .limit(1);
+
+    final ResultSet rs = session.execute(selectStmt);
+    final Row row = rs.one();
+    assertThat(row, notNullValue());
+    assertThat(rs.isExhausted(), is(true));
+    assertThat(row.getString("field0"), is("new-value1"));
+    assertThat(row.getString("field1"), is("new-value2"));
+  }
+
+  @Test
+  public void testDelete() throws Exception {
+    insertRow();
+
+    final Status status = client.delete(TABLE, DEFAULT_ROW_KEY);
+    assertThat(status, is(Status.OK));
+
+    // Verify result
+    final Select selectStmt =
+        QueryBuilder.select("field0", "field1")
+            .from(TABLE)
+            .where(QueryBuilder.eq(CassandraCQLClient.YCSB_KEY, DEFAULT_ROW_KEY))
+            .limit(1);
+
+    final ResultSet rs = session.execute(selectStmt);
+    final Row row = rs.one();
+    assertThat(row, nullValue());
+  }
+
+  @Test
+  public void testPreparedStatements() throws Exception {
+    final int LOOP_COUNT = 3;
+    for (int i = 0; i < LOOP_COUNT; i++) {
+      testInsert();
+      testUpdate();
+      testRead();
+      testReadSingleColumn();
+      testReadMissingRow();
+      testDelete();
+    }
+  }
+}

code/cppclient/YCSB/cassandra/src/test/resources/ycsb.cql

+/**
+ * Copyright (c) 2015 YCSB Contributors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+CREATE TABLE usertable (
+  y_id varchar primary key,
+  field0 varchar,
+  field1 varchar,
+  field2 varchar,
+  field3 varchar,
+  field4 varchar,
+  field5 varchar,
+  field6 varchar,
+  field7 varchar,
+  field8 varchar,
+  field9 varchar);

code/cppclient/YCSB/checkstyle.xml

+<?xml version="1.0"?>
+<!-- 
+Copyright (c) 2012 - 2016 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+<!DOCTYPE module PUBLIC
+    "-//Puppy Crawl//DTD Check Configuration 1.2//EN"
+    "http://www.puppycrawl.com/dtds/configuration_1_2.dtd">
+
+<!--
+
+  Checkstyle configuration for Hadoop that is based on the sun_checks.xml file
+  that is bundled with Checkstyle and includes checks for:
+
+    - the Java Language Specification at
+      http://java.sun.com/docs/books/jls/second_edition/html/index.html
+
+    - the Sun Code Conventions at http://java.sun.com/docs/codeconv/
+
+    - the Javadoc guidelines at
+      http://java.sun.com/j2se/javadoc/writingdoccomments/index.html
+
+    - the JDK Api documentation http://java.sun.com/j2se/docs/api/index.html
+
+    - some best practices
+
+  Checkstyle is very configurable. Be sure to read the documentation at
+  http://checkstyle.sf.net (or in your downloaded distribution).
+
+  Most Checks are configurable, be sure to consult the documentation.
+
+  To completely disable a check, just comment it out or delete it from the file.
+
+  Finally, it is worth reading the documentation.
+
+-->
+
+<module name="Checker">
+
+    <!-- Checks that a package.html file exists for each package.     -->
+    <!-- See http://checkstyle.sf.net/config_javadoc.html#PackageHtml -->
+    <module name="JavadocPackage"/>
+
+    <!-- Checks whether files end with a new line.                        -->
+    <!-- See http://checkstyle.sf.net/config_misc.html#NewlineAtEndOfFile -->
+    <!-- module name="NewlineAtEndOfFile"/-->
+
+    <!-- Checks that property files contain the same keys.         -->
+    <!-- See http://checkstyle.sf.net/config_misc.html#Translation -->
+    <module name="Translation"/>
+
+    <module name="FileLength"/>
+    <module name="FileTabCharacter"/>
+
+    <module name="TreeWalker">
+
+        <!-- Checks for Javadoc comments.                     -->
+        <!-- See http://checkstyle.sf.net/config_javadoc.html -->
+        <module name="JavadocType">
+          <property name="scope" value="public"/>
+          <property name="allowMissingParamTags" value="true"/>
+          <!-- unfortunately we cannot add implNote, implSpec, apiNote and apiSpec to checkstyle -->
+          <property name="allowUnknownTags" value="true"/>
+        </module>
+        <module name="JavadocStyle"/>
+
+        <!-- Checks for Naming Conventions.                  -->
+        <!-- See http://checkstyle.sf.net/config_naming.html -->
+        <module name="ConstantName"/>
+        <module name="LocalFinalVariableName"/>
+        <module name="LocalVariableName"/>
+        <module name="MemberName"/>
+        <module name="MethodName"/>
+        <module name="PackageName"/>
+        <module name="ParameterName"/>
+        <module name="StaticVariableName"/>
+        <module name="TypeName"/>
+
+
+        <!-- Checks for Headers                                -->
+        <!-- See http://checkstyle.sf.net/config_header.html   -->
+        <!-- <module name="Header">                            -->
+            <!-- The follow property value demonstrates the ability     -->
+            <!-- to have access to ANT properties. In this case it uses -->
+            <!-- the ${basedir} property to allow Checkstyle to be run  -->
+            <!-- from any directory within a project. See property      -->
+            <!-- expansion,                                             -->
+            <!-- http://checkstyle.sf.net/config.html#properties        -->
+            <!-- <property                                              -->
+            <!--     name="headerFile"                                  -->
+            <!--     value="${basedir}/java.header"/>                   -->
+        <!-- </module> -->
+
+        <!-- Following interprets the header file as regular expressions. -->
+        <!-- <module name="RegexpHeader"/>                                -->
+
+
+        <!-- Checks for imports                              -->
+        <!-- See http://checkstyle.sf.net/config_import.html -->
+        <module name="IllegalImport"/> <!-- defaults to sun.* packages -->
+        <module name="RedundantImport"/>
+        <module name="UnusedImports"/>
+
+
+        <!-- Checks for Size Violations.                    -->
+        <!-- See http://checkstyle.sf.net/config_sizes.html -->
+        <module name="LineLength">
+            <property name="max" value="120"/>
+        </module>
+        <module name="MethodLength"/>
+        <module name="ParameterNumber"/>
+
+
+        <!-- Checks for whitespace                               -->
+        <!-- See http://checkstyle.sf.net/config_whitespace.html -->
+        <module name="EmptyForIteratorPad"/>
+        <module name="MethodParamPad"/>
+        <module name="NoWhitespaceAfter"/>
+        <module name="NoWhitespaceBefore"/>
+        <module name="ParenPad"/>
+        <module name="TypecastParenPad"/>
+        <module name="WhitespaceAfter">
+	    	<property name="tokens" value="COMMA, SEMI"/>
+		</module>
+
+
+        <!-- Modifier Checks                                    -->
+        <!-- See http://checkstyle.sf.net/config_modifiers.html -->
+        <module name="ModifierOrder"/>
+        <module name="RedundantModifier"/>
+
+
+        <!-- Checks for blocks. You know, those {}'s         -->
+        <!-- See http://checkstyle.sf.net/config_blocks.html -->
+        <module name="AvoidNestedBlocks"/>
+        <module name="EmptyBlock">
+          <property name="option" value="text"/>
+        </module>
+        <module name="LeftCurly"/>
+        <module name="NeedBraces"/>
+        <module name="RightCurly"/>
+
+
+        <!-- Checks for common coding problems               -->
+        <!-- See http://checkstyle.sf.net/config_coding.html -->
+        <!-- module name="AvoidInlineConditionals"/-->
+        <module name="EmptyStatement"/>
+        <module name="EqualsHashCode"/>
+        <module name="HiddenField">
+          <property name="ignoreConstructorParameter" value="true"/>
+        </module>
+        <module name="IllegalInstantiation"/>
+        <module name="InnerAssignment"/>
+        <module name="MissingSwitchDefault"/>
+        <module name="SimplifyBooleanExpression"/>
+        <module name="SimplifyBooleanReturn"/>
+
+        <!-- Checks for class design                         -->
+        <!-- See http://checkstyle.sf.net/config_design.html -->
+        <module name="FinalClass"/>
+        <module name="HideUtilityClassConstructor"/>
+        <module name="InterfaceIsType"/>
+        <module name="VisibilityModifier">
+          <property name="protectedAllowed" value="true"/>
+        </module>
+
+
+        <!-- Miscellaneous other checks.                   -->
+        <!-- See http://checkstyle.sf.net/config_misc.html -->
+        <module name="ArrayTypeStyle"/>
+        <module name="Indentation">
+            <property name="basicOffset" value="2" />
+            <property name="caseIndent" value="0" />
+        </module> 
+        <!-- <module name="TodoComment"/> -->
+        <module name="UpperEll"/>
+
+    </module>
+
+</module>

code/cppclient/YCSB/core/CHANGES.md

+<!--
+Copyright (c) 2015 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+When used as a latency under load benchmark YCSB in it's original form suffers from
+Coordinated Omission[1] and related measurement issue:
+
+* Load is controlled by response time
+* Measurement does not account for missing time
+* Measurement starts at beginning of request rather than at intended beginning
+* Measurement is limited in scope as the histogram does not provide data on overflow values
+
+To provide a minimal correction patch the following were implemented:
+
+1. Replace internal histogram implementation with HdrHistogram[2]:
+HdrHistogram offers a dynamic range of measurement at a given precision and will
+improve the fidelity of reporting. It allows capturing a much wider range of latencies.
+HdrHistogram also supports compressed loss-less serialization which enable capturing
+snapshot histograms from which lower resolution histograms can be constructed for plotting
+latency over time. Snapshot interval histograms are serialized on status reporting which
+must be enabled using the '-s' option.
+ 
+2. Track intended operation start and report latencies from that point in time:
+Assuming the benchmark sets a target schedule of execution in which every operation
+is supposed to happen at a given time the benchmark should measure the latency between
+intended start time and operation completion.
+This required the introduction of a new measurement point and inevitably
+includes measuring some of the internal preparation steps of the load generator.
+These overhead should be negligible in the context of a network hop, but could
+be corrected for by estimating the load-generator overheads (e.g. by measuring a
+no-op DB or by measuring the setup time for an operation and deducting that from total).
+This intended measurement point is only used when there is a target load (specified by
+the -target paramaeter)
+
+This branch supports the following new options:
+
+* -p measurementtype=[histogram|hdrhistogram|hdrhistogram+histogram|timeseries] (default=histogram)
+The new measurement types are hdrhistogram and hdrhistogram+histogram. Default is still
+histogram, which is the old histogram. Ultimately we would remove the old measurement types
+and use only HdrHistogram but the old measurement is left in there for comparison sake.
+
+* -p measurement.interval=[op|intended|both] (default=op)
+This new option deferentiates between measured intervals and adds the intended interval(as described)
+above, and the option to record both the op and intended for comparison.
+
+* -p hdrhistogram.fileoutput=[true|false] (default=false)
+This new option will enable periodical writes of the interval histogram into an output file. The path can be set using '-p hdrhistogram.output.path=<PATH>'.
+
+Example parameters:
+-target 1000 -s -p workload=site.ycsb.workloads.CoreWorkload -p basicdb.verbose=false -p basicdb.simulatedelay=4 -p measurement.interval=both -p measurementtype=hdrhistogram -p hdrhistogram.fileoutput=true -p maxexecutiontime=60
+
+Further changes made:
+
+* -p status.interval=<number of seconds> (default=10)
+Controls the number of seconds between status reports and therefore between HdrHistogram snapshots reported.
+
+* -p basicdb.randomizedelay=[true|false] (default=true)
+Controls weather the delay simulated by the mock DB is uniformly random or not.
+
+Further suggestions:
+
+1. Correction load control: currently after a pause the load generator will do
+operations back to back to catchup, this leads to a flat out throughput mode
+of testing as opposed to controlled load.
+
+2. Move to async model: Scenarios where Ops have no dependency could delegate the
+Op execution to a threadpool and thus separate the request rate control from the
+synchronous execution of Ops. Measurement would start on queuing for execution.
+
+1. https://groups.google.com/forum/#!msg/mechanical-sympathy/icNZJejUHfE/BfDekfBEs_sJ
+2. https://github.com/HdrHistogram/HdrHistogram
\ No newline at end of file

code/cppclient/YCSB/core/pom.xml

+<?xml version="1.0" encoding="UTF-8"?>
+<!-- 
+Copyright (c) 2012 - 2016 YCSB contributors. All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License"); you
+may not use this file except in compliance with the License. You
+may obtain a copy of the License at
+
+http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+implied. See the License for the specific language governing
+permissions and limitations under the License. See accompanying
+LICENSE file.
+-->
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/maven-v4_0_0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+  <parent>
+    <groupId>site.ycsb</groupId>
+    <artifactId>root</artifactId>
+    <version>0.18.0-SNAPSHOT</version>
+  </parent>
+  
+  <artifactId>core</artifactId>
+  <name>Core YCSB</name>
+  <packaging>jar</packaging>
+
+  <properties>
+     <jackson.api.version>1.9.4</jackson.api.version>
+  </properties>
+
+  <dependencies>	
+    <dependency>
+      <groupId>org.apache.htrace</groupId>
+      <artifactId>htrace-core4</artifactId>
+      <version>4.1.0-incubating</version>
+    </dependency>
+    <dependency>
+      <groupId>org.codehaus.jackson</groupId>
+      <artifactId>jackson-mapper-asl</artifactId>
+      <version>${jackson.api.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.codehaus.jackson</groupId>
+      <artifactId>jackson-core-asl</artifactId>
+      <version>${jackson.api.version}</version>
+    </dependency>
+    <dependency>
+      <groupId>org.testng</groupId>
+      <artifactId>testng</artifactId>
+      <version>6.1.1</version>
+      <scope>test</scope>
+    </dependency>
+    <dependency>
+      <groupId>org.hdrhistogram</groupId>
+      <artifactId>HdrHistogram</artifactId>
+      <version>2.1.4</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <resources>
+      <resource>
+        <directory>src/main/resources</directory>
+        <filtering>true</filtering>
+      </resource>
+    </resources>
+  </build>
+  
+  <profiles>
+    <profile>
+      <!-- Build profile when running via yscb.sh or yscb.bat-->
+      <id>source-run</id>
+      <build>
+        <plugins>
+          <plugin>
+            <groupId>org.apache.maven.plugins</groupId>
+            <artifactId>maven-dependency-plugin</artifactId>
+            <executions>
+              <execution>
+                <id>stage-dependencies</id>
+                <phase>package</phase>
+                <goals>
+                  <goal>copy-dependencies</goal>
+                </goals>
+                <configuration>
+                  <includeScope>runtime</includeScope>
+                </configuration>
+              </execution>
+            </executions>
+          </plugin>
+        </plugins>
+      </build>
+    </profile>
+  </profiles>
+</project>

code/cppclient/YCSB/core/src/main/java/site/ycsb/BasicTSDB.java

+/**
+ * Copyright (c) 2017 YCSB contributors All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+package site.ycsb;
+
+import java.util.HashMap;
+import java.util.HashSet;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.Set;
+import java.util.TreeMap;
+
+import site.ycsb.workloads.TimeSeriesWorkload;
+
+/**
+ * Basic DB for printing out time series workloads and/or tracking the distribution
+ * of keys and fields.
+ */
+public class BasicTSDB extends BasicDB {
+
+  /** Time series workload specific counters. */
+  protected static Map<Long, Integer> timestamps;
+  protected static Map<Integer, Integer> floats;
+  protected static Map<Integer, Integer> integers;
+  
+  private String timestampKey;
+  private String valueKey;
+  private String tagPairDelimiter;
+  private String queryTimeSpanDelimiter;
+  private long lastTimestamp;
+  
+  @Override
+  public void init() {
+    super.init();
+    
+    synchronized (MUTEX) {
+      if (timestamps == null) {
+        timestamps = new HashMap<Long, Integer>();
+        floats = new HashMap<Integer, Integer>();
+        integers = new HashMap<Integer, Integer>();
+      }
+    }
+    
+    timestampKey = getProperties().getProperty(
+        TimeSeriesWorkload.TIMESTAMP_KEY_PROPERTY, 
+        TimeSeriesWorkload.TIMESTAMP_KEY_PROPERTY_DEFAULT);
+    valueKey = getProperties().getProperty(
+        TimeSeriesWorkload.VALUE_KEY_PROPERTY, 
+        TimeSeriesWorkload.VALUE_KEY_PROPERTY_DEFAULT);
+    tagPairDelimiter = getProperties().getProperty(
+        TimeSeriesWorkload.PAIR_DELIMITER_PROPERTY, 
+        TimeSeriesWorkload.PAIR_DELIMITER_PROPERTY_DEFAULT);
+    queryTimeSpanDelimiter = getProperties().getProperty(
+        TimeSeriesWorkload.QUERY_TIMESPAN_DELIMITER_PROPERTY,
+        TimeSeriesWorkload.QUERY_TIMESPAN_DELIMITER_PROPERTY_DEFAULT);
+  }
+  
+  public Status read(String table, String key, Set<String> fields, Map<String, ByteIterator> result) {
+    delay();
+    
+    if (verbose) {
+      StringBuilder sb = getStringBuilder();
+      sb.append("READ ").append(table).append(" ").append(key).append(" [ ");
+      if (fields != null) {
+        for (String f : fields) {
+          sb.append(f).append(" ");
+        }
+      } else {
+        sb.append("<all fields>");
+      }
+
+      sb.append("]");
+      System.out.println(sb);
+    }
+
+    if (count) {
+      Set<String> filtered = null;
+      if (fields != null) {
+        filtered = new HashSet<String>();
+        for (final String field : fields) {
+          if (field.startsWith(timestampKey)) {
+            String[] parts = field.split(tagPairDelimiter);
+            if (parts[1].contains(queryTimeSpanDelimiter)) {
+              parts = parts[1].split(queryTimeSpanDelimiter);
+              lastTimestamp = Long.parseLong(parts[0]);
+            } else {
+              lastTimestamp = Long.parseLong(parts[1]);
+            }
+            synchronized(timestamps) {
+              Integer ctr = timestamps.get(lastTimestamp);
+              if (ctr == null) {
+                timestamps.put(lastTimestamp, 1);
+              } else {
+                timestamps.put(lastTimestamp, ctr + 1);
+              }
+            }
+          } else {
+            filtered.add(field);
+          }
+        }
+      }
+      incCounter(reads, hash(table, key, filtered));
+    }
+    return Status.OK;
+  }
+  
+  @Override
+  public Status update(String table, String key, Map<String, ByteIterator> values) {
+    delay();
+
+    boolean isFloat = false;
+    
+    if (verbose) {
+      StringBuilder sb = getStringBuilder();
+      sb.append("UPDATE ").append(table).append(" ").append(key).append(" [ ");
+      if (values != null) {
+        final TreeMap<String, ByteIterator> tree = new TreeMap<String, ByteIterator>(values);
+        for (Map.Entry<String, ByteIterator> entry : tree.entrySet()) {
+          if (entry.getKey().equals(timestampKey)) {
+            sb.append(entry.getKey()).append("=")
+              .append(Utils.bytesToLong(entry.getValue().toArray())).append(" ");
+          } else if (entry.getKey().equals(valueKey)) {
+            final NumericByteIterator it = (NumericByteIterator) entry.getValue();
+            isFloat = it.isFloatingPoint();
+            sb.append(entry.getKey()).append("=")
+               .append(isFloat ? it.getDouble() : it.getLong()).append(" ");
+          } else {
+            sb.append(entry.getKey()).append("=").append(entry.getValue()).append(" ");
+          }
+        }
+      }
+      sb.append("]");
+      System.out.println(sb);
+    }
+
+    if (count) {
+      if (!verbose) {
+        isFloat = ((NumericByteIterator) values.get(valueKey)).isFloatingPoint();
+      }
+      int hash = hash(table, key, values);
+      incCounter(updates, hash);
+      synchronized(timestamps) {
+        Integer ctr = timestamps.get(lastTimestamp);
+        if (ctr == null) {
+          timestamps.put(lastTimestamp, 1);
+        } else {
+          timestamps.put(lastTimestamp, ctr + 1);
+        }
+      }
+      if (isFloat) {
+        incCounter(floats, hash);
+      } else {
+        incCounter(integers, hash);
+      }
+    }
+    
+    return Status.OK;
+  }
+
+  @Override
+  public Status insert(String table, String key, Map<String, ByteIterator> values) {
+    delay();
+    
+    boolean isFloat = false;
+    
+    if (verbose) {
+      StringBuilder sb = getStringBuilder();
+      sb.append("INSERT ").append(table).append(" ").append(key).append(" [ ");
+      if (values != null) {
+        final TreeMap<String, ByteIterator> tree = new TreeMap<String, ByteIterator>(values);
+        for (Map.Entry<String, ByteIterator> entry : tree.entrySet()) {
+          if (entry.getKey().equals(timestampKey)) {
+            sb.append(entry.getKey()).append("=")
+              .append(Utils.bytesToLong(entry.getValue().toArray())).append(" ");
+          } else if (entry.getKey().equals(valueKey)) {
+            final NumericByteIterator it = (NumericByteIterator) entry.getValue();
+            isFloat = it.isFloatingPoint();
+            sb.append(entry.getKey()).append("=")
+              .append(isFloat ? it.getDouble() : it.getLong()).append(" ");
+          } else {
+            sb.append(entry.getKey()).append("=").append(entry.getValue()).append(" ");
+          }
+        }
+      }
+      sb.append("]");
+      System.out.println(sb);
+    }
+
+    if (count) {
+      if (!verbose) {
+        isFloat = ((NumericByteIterator) values.get(valueKey)).isFloatingPoint();
+      }
+      int hash = hash(table, key, values);
+      incCounter(inserts, hash);
+      synchronized(timestamps) {
+        Integer ctr = timestamps.get(lastTimestamp);
+        if (ctr == null) {
+          timestamps.put(lastTimestamp, 1);
+        } else {
+          timestamps.put(lastTimestamp, ctr + 1);
+        }
+      }
+      if (isFloat) {
+        incCounter(floats, hash);
+      } else {
+        incCounter(integers, hash);
+      }
+    }
+
+    return Status.OK;
+  }
+
+  @Override
+  public void cleanup() {
+    super.cleanup();
+    if (count && counter < 1) {
+      System.out.println("[TIMESTAMPS], Unique, " + timestamps.size());
+      System.out.println("[FLOATS], Unique series, " + floats.size());
+      System.out.println("[INTEGERS], Unique series, " + integers.size());
+      
+      long minTs = Long.MAX_VALUE;
+      long maxTs = Long.MIN_VALUE;
+      for (final long ts : timestamps.keySet()) {
+        if (ts > maxTs) {
+          maxTs = ts;
+        }
+        if (ts < minTs) {
+          minTs = ts;
+        }
+      }
+      System.out.println("[TIMESTAMPS], Min, " + minTs);
+      System.out.println("[TIMESTAMPS], Max, " + maxTs);
+    }
+  }
+  
+  @Override
+  protected int hash(final String table, final String key, final Map<String, ByteIterator> values) {
+    final TreeMap<String, ByteIterator> sorted = new TreeMap<String, ByteIterator>();
+    for (final Entry<String, ByteIterator> entry : values.entrySet()) {
+      if (entry.getKey().equals(valueKey)) {
+        continue;
+      } else if (entry.getKey().equals(timestampKey)) {
+        lastTimestamp = ((NumericByteIterator) entry.getValue()).getLong();
+        entry.getValue().reset();
+        continue;
+      }
+      sorted.put(entry.getKey(), entry.getValue());
+    }
+    // yeah it's ugly but gives us a unique hash without having to add hashers
+    // to all of the ByteIterators.
+    StringBuilder buf = new StringBuilder().append(table).append(key);
+    for (final Entry<String, ByteIterator> entry : sorted.entrySet()) {
+      entry.getValue().reset();
+      buf.append(entry.getKey())
+         .append(entry.getValue().toString());
+    }
+    return buf.toString().hashCode();
+  }
+  
+}
\ No newline at end of file

code/cppclient/YCSB/core/src/main/java/site/ycsb/ByteArrayByteIterator.java

+/**
+ * Copyright (c) 2010-2016 Yahoo! Inc., 2017 YCSB contributors All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+package site.ycsb;
+
+/**
+ *  A ByteIterator that iterates through a byte array.
+ */
+public class ByteArrayByteIterator extends ByteIterator {
+  private final int originalOffset;
+  private final byte[] str;
+  private int off;
+  private final int len;
+
+  public ByteArrayByteIterator(byte[] s) {
+    this.str = s;
+    this.off = 0;
+    this.len = s.length;
+    originalOffset = 0;
+  }
+
+  public ByteArrayByteIterator(byte[] s, int off, int len) {
+    this.str = s;
+    this.off = off;
+    this.len = off + len;
+    originalOffset = off;
+  }
+
+  @Override
+  public boolean hasNext() {
+    return off < len;
+  }
+
+  @Override
+  public byte nextByte() {
+    byte ret = str[off];
+    off++;
+    return ret;
+  }
+
+  @Override
+  public long bytesLeft() {
+    return len - off;
+  }
+
+  @Override
+  public void reset() {
+    off = originalOffset;
+  }
+
+  @Override
+  public byte[] toArray() {
+    int size = (int) bytesLeft();
+    byte[] bytes = new byte[size];
+    System.arraycopy(str, off, bytes, 0, size);
+    off = len;
+    return bytes;
+  }
+
+}

code/cppclient/YCSB/core/src/main/java/site/ycsb/ByteIterator.java

+/**
+ * Copyright (c) 2010-2016 Yahoo! Inc., 2017 YCSB contributors All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+package site.ycsb;
+
+import java.nio.ByteBuffer;
+import java.nio.CharBuffer;
+import java.nio.charset.Charset;
+import java.util.Iterator;
+
+/**
+ * YCSB-specific buffer class.  ByteIterators are designed to support
+ * efficient field generation, and to allow backend drivers that can stream
+ * fields (instead of materializing them in RAM) to do so.
+ * <p>
+ * YCSB originially used String objects to represent field values.  This led to
+ * two performance issues.
+ * </p><p>
+ * First, it leads to unnecessary conversions between UTF-16 and UTF-8, both
+ * during field generation, and when passing data to byte-based backend
+ * drivers.
+ * </p><p>
+ * Second, Java strings are represented internally using UTF-16, and are
+ * built by appending to a growable array type (StringBuilder or
+ * StringBuffer), then calling a toString() method.  This leads to a 4x memory
+ * overhead as field values are being built, which prevented YCSB from
+ * driving large object stores.
+ * </p>
+ * The StringByteIterator class contains a number of convenience methods for
+ * backend drivers that convert between Map&lt;String,String&gt; and
+ * Map&lt;String,ByteBuffer&gt;.
+ *
+ */
+public abstract class ByteIterator implements Iterator<Byte> {
+
+  @Override
+  public abstract boolean hasNext();
+
+  @Override
+  public Byte next() {
+    throw new UnsupportedOperationException();
+  }
+
+  public abstract byte nextByte();
+
+  /** @return byte offset immediately after the last valid byte */
+  public int nextBuf(byte[] buf, int bufOff) {
+    int sz = bufOff;
+    while (sz < buf.length && hasNext()) {
+      buf[sz] = nextByte();
+      sz++;
+    }
+    return sz;
+  }
+
+  public abstract long bytesLeft();
+
+  @Override
+  public void remove() {
+    throw new UnsupportedOperationException();
+  }
+
+  /** Resets the iterator so that it can be consumed again. Not all
+   * implementations support this call.
+   * @throws UnsupportedOperationException if the implementation hasn't implemented
+   * the method.
+   */
+  public void reset() {
+    throw new UnsupportedOperationException();
+  }
+  
+  /** Consumes remaining contents of this object, and returns them as a string. */
+  public String toString() {
+    Charset cset = Charset.forName("UTF-8");
+    CharBuffer cb = cset.decode(ByteBuffer.wrap(this.toArray()));
+    return cb.toString();
+  }
+
+  /** Consumes remaining contents of this object, and returns them as a byte array. */
+  public byte[] toArray() {
+    long left = bytesLeft();
+    if (left != (int) left) {
+      throw new ArrayIndexOutOfBoundsException("Too much data to fit in one array!");
+    }
+    byte[] ret = new byte[(int) left];
+    for (int i = 0; i < ret.length; i++) {
+      ret[i] = nextByte();
+    }
+    return ret;
+  }
+
+}

code/cppclient/YCSB/core/src/main/java/site/ycsb/ClientThread.java

+/**
+ * Copyright (c) 2010-2016 Yahoo! Inc., 2017 YCSB contributors All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+package site.ycsb;
+
+import site.ycsb.measurements.Measurements;
+import java.util.Properties;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.locks.LockSupport;
+
+/**
+ * A thread for executing transactions or data inserts to the database.
+ */
+public class ClientThread implements Runnable {
+  // Counts down each of the clients completing.
+  private final CountDownLatch completeLatch;
+
+  private static boolean spinSleep;
+  private DB db;
+  private boolean dotransactions;
+  private Workload workload;
+  private int opcount;
+  private double targetOpsPerMs;
+
+  private int opsdone;
+  private int threadid;
+  private int threadcount;
+  private Object workloadstate;
+  private Properties props;
+  private long targetOpsTickNs;
+  private final Measurements measurements;
+
+  /**
+   * Constructor.
+   *
+   * @param db                   the DB implementation to use
+   * @param dotransactions       true to do transactions, false to insert data
+   * @param workload             the workload to use
+   * @param props                the properties defining the experiment
+   * @param opcount              the number of operations (transactions or inserts) to do
+   * @param targetperthreadperms target number of operations per thread per ms
+   * @param completeLatch        The latch tracking the completion of all clients.
+   */
+  public ClientThread(DB db, boolean dotransactions, Workload workload, Properties props, int opcount,
+                      double targetperthreadperms, CountDownLatch completeLatch) {
+    this.db = db;
+    this.dotransactions = dotransactions;
+    this.workload = workload;
+    this.opcount = opcount;
+    opsdone = 0;
+    if (targetperthreadperms > 0) {
+      targetOpsPerMs = targetperthreadperms;
+      targetOpsTickNs = (long) (1000000 / targetOpsPerMs);
+    }
+    this.props = props;
+    measurements = Measurements.getMeasurements();
+    spinSleep = Boolean.valueOf(this.props.getProperty("spin.sleep", "false"));
+    this.completeLatch = completeLatch;
+  }
+
+  public void setThreadId(final int threadId) {
+    threadid = threadId;
+  }
+
+  public void setThreadCount(final int threadCount) {
+    threadcount = threadCount;
+  }
+
+  public int getOpsDone() {
+    return opsdone;
+  }
+
+  @Override
+  public void run() {
+    try {
+      db.init();
+    } catch (DBException e) {
+      e.printStackTrace();
+      e.printStackTrace(System.out);
+      return;
+    }
+
+    try {
+      workloadstate = workload.initThread(props, threadid, threadcount);
+    } catch (WorkloadException e) {
+      e.printStackTrace();
+      e.printStackTrace(System.out);
+      return;
+    }
+
+    //NOTE: Switching to using nanoTime and parkNanos for time management here such that the measurements
+    // and the client thread have the same view on time.
+
+    //spread the thread operations out so they don't all hit the DB at the same time
+    // GH issue 4 - throws exception if _target>1 because random.nextInt argument must be >0
+    // and the sleep() doesn't make sense for granularities < 1 ms anyway
+    if ((targetOpsPerMs > 0) && (targetOpsPerMs <= 1.0)) {
+      long randomMinorDelay = ThreadLocalRandom.current().nextInt((int) targetOpsTickNs);
+      sleepUntil(System.nanoTime() + randomMinorDelay);
+    }
+    try {
+      if (dotransactions) {
+        long startTimeNanos = System.nanoTime();
+
+        while (((opcount == 0) || (opsdone < opcount)) && !workload.isStopRequested()) {
+
+          if (!workload.doTransaction(db, workloadstate)) {
+            break;
+          }
+
+          opsdone++;
+
+          throttleNanos(startTimeNanos);
+        }
+      } else {
+        long startTimeNanos = System.nanoTime();
+
+        while (((opcount == 0) || (opsdone < opcount)) && !workload.isStopRequested()) {
+
+          if (!workload.doInsert(db, workloadstate)) {
+            break;
+          }
+
+          opsdone++;
+
+          throttleNanos(startTimeNanos);
+        }
+      }
+    } catch (Exception e) {
+      e.printStackTrace();
+      e.printStackTrace(System.out);
+      System.exit(0);
+    }
+
+    try {
+      measurements.setIntendedStartTimeNs(0);
+      db.cleanup();
+    } catch (DBException e) {
+      e.printStackTrace();
+      e.printStackTrace(System.out);
+    } finally {
+      completeLatch.countDown();
+    }
+  }
+
+  private static void sleepUntil(long deadline) {
+    while (System.nanoTime() < deadline) {
+      if (!spinSleep) {
+        LockSupport.parkNanos(deadline - System.nanoTime());
+      }
+    }
+  }
+
+  private void throttleNanos(long startTimeNanos) {
+    //throttle the operations
+    if (targetOpsPerMs > 0) {
+      // delay until next tick
+      long deadline = startTimeNanos + opsdone * targetOpsTickNs;
+      sleepUntil(deadline);
+      measurements.setIntendedStartTimeNs(deadline);
+    }
+  }
+
+  /**
+   * The total amount of work this thread is still expected to do.
+   */
+  int getOpsTodo() {
+    int todo = opcount - opsdone;
+    return todo < 0 ? 0 : todo;
+  }
+}

code/cppclient/YCSB/core/src/main/java/site/ycsb/DB.java

+/**
+ * Copyright (c) 2010-2016 Yahoo! Inc., 2017 YCSB contributors All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+package site.ycsb;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Properties;
+import java.util.Set;
+import java.util.Vector;
+
+/**
+ * A layer for accessing a database to be benchmarked. Each thread in the client
+ * will be given its own instance of whatever DB class is to be used in the test.
+ * This class should be constructed using a no-argument constructor, so we can
+ * load it dynamically. Any argument-based initialization should be
+ * done by init().
+ *
+ * Note that YCSB does not make any use of the return codes returned by this class.
+ * Instead, it keeps a count of the return values and presents them to the user.
+ *
+ * The semantics of methods such as insert, update and delete vary from database
+ * to database.  In particular, operations may or may not be durable once these
+ * methods commit, and some systems may return 'success' regardless of whether
+ * or not a tuple with a matching key existed before the call.  Rather than dictate
+ * the exact semantics of these methods, we recommend you either implement them
+ * to match the database's default semantics, or the semantics of your 
+ * target application.  For the sake of comparison between experiments we also 
+ * recommend you explain the semantics you chose when presenting performance results.
+ */
+public abstract class DB {
+  /**
+   * Properties for configuring this DB.
+   */
+  private Properties properties = new Properties();
+
+  /**
+   * Set the properties for this DB.
+   */
+  public void setProperties(Properties p) {
+    properties = p;
+
+  }
+
+  /**
+   * Get the set of properties for this DB.
+   */
+  public Properties getProperties() {
+    return properties;
+  }
+
+  /**
+   * Initialize any state for this DB.
+   * Called once per DB instance; there is one DB instance per client thread.
+   */
+  public void init() throws DBException {
+  }
+
+  /**
+   * Cleanup any state for this DB.
+   * Called once per DB instance; there is one DB instance per client thread.
+   */
+  public void cleanup() throws DBException {
+  }
+
+  /**
+   * Read a record from the database. Each field/value pair from the result will be stored in a HashMap.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to read.
+   * @param fields The list of fields to read, or null for all of them
+   * @param result A HashMap of field/value pairs for the result
+   * @return The result of the operation.
+   */
+  public abstract Status read(String table, String key, Set<String> fields, Map<String, ByteIterator> result);
+
+  /**
+   * Perform a range scan for a set of records in the database. Each field/value pair from the result will be stored
+   * in a HashMap.
+   *
+   * @param table The name of the table
+   * @param startkey The record key of the first record to read.
+   * @param recordcount The number of records to read
+   * @param fields The list of fields to read, or null for all of them
+   * @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one record
+   * @return The result of the operation.
+   */
+  public abstract Status scan(String table, String startkey, int recordcount, Set<String> fields,
+                              Vector<HashMap<String, ByteIterator>> result);
+
+  /**
+   * Update a record in the database. Any field/value pairs in the specified values HashMap will be written into the
+   * record with the specified record key, overwriting any existing values with the same field name.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to write.
+   * @param values A HashMap of field/value pairs to update in the record
+   * @return The result of the operation.
+   */
+  public abstract Status update(String table, String key, Map<String, ByteIterator> values);
+
+  /**
+   * Insert a record in the database. Any field/value pairs in the specified values HashMap will be written into the
+   * record with the specified record key.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to insert.
+   * @param values A HashMap of field/value pairs to insert in the record
+   * @return The result of the operation.
+   */
+  public abstract Status insert(String table, String key, Map<String, ByteIterator> values);
+
+  /**
+   * Delete a record from the database.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to delete.
+   * @return The result of the operation.
+   */
+  public abstract Status delete(String table, String key);
+}

code/cppclient/YCSB/core/src/main/java/site/ycsb/DBException.java

+/**
+ * Copyright (c) 2010-2016 Yahoo! Inc., 2017 YCSB contributors All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+package site.ycsb;
+
+/**
+ * Something bad happened while interacting with the database.
+ */
+public class DBException extends Exception {
+  /**
+   *
+   */
+  private static final long serialVersionUID = 6646883591588721475L;
+
+  public DBException(String message) {
+    super(message);
+  }
+
+  public DBException() {
+    super();
+  }
+
+  public DBException(String message, Throwable cause) {
+    super(message, cause);
+  }
+
+  public DBException(Throwable cause) {
+    super(cause);
+  }
+
+}

code/cppclient/YCSB/core/src/main/java/site/ycsb/DBFactory.java

+/**
+ * Copyright (c) 2010-2016 Yahoo! Inc., 2017 YCSB contributors All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+package site.ycsb;
+
+import org.apache.htrace.core.Tracer;
+
+import java.util.Properties;
+
+/**
+ * Creates a DB layer by dynamically classloading the specified DB class.
+ */
+public final class DBFactory {
+  private DBFactory() {
+    // not used
+  }
+
+  public static DB newDB(String dbname, Properties properties, final Tracer tracer) throws UnknownDBException {
+    ClassLoader classLoader = DBFactory.class.getClassLoader();
+
+    DB ret;
+
+    try {
+      Class dbclass = classLoader.loadClass(dbname);
+
+      ret = (DB) dbclass.newInstance();
+    } catch (Exception e) {
+      e.printStackTrace();
+      return null;
+    }
+
+    ret.setProperties(properties);
+
+    return new DBWrapper(ret, tracer);
+  }
+
+}

code/cppclient/YCSB/core/src/main/java/site/ycsb/GoodBadUglyDB.java

+/**
+ * Copyright (c) 2010 Yahoo! Inc. All rights reserved.
+ * <p>
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+
+package site.ycsb;
+
+import java.util.HashMap;
+import java.util.Map;
+import java.util.Random;
+import java.util.Set;
+import java.util.Vector;
+import java.util.concurrent.ThreadLocalRandom;
+import java.util.concurrent.locks.Lock;
+import java.util.concurrent.locks.LockSupport;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+import static java.util.concurrent.TimeUnit.MICROSECONDS;
+
+/**
+ * Basic DB that just prints out the requested operations, instead of doing them against a database.
+ */
+public class GoodBadUglyDB extends DB {
+  public static final String SIMULATE_DELAY = "gbudb.delays";
+  public static final String SIMULATE_DELAY_DEFAULT = "200,1000,10000,50000,100000";
+  private static final ReadWriteLock DB_ACCESS = new ReentrantReadWriteLock();
+  private long[] delays;
+
+  public GoodBadUglyDB() {
+    delays = new long[]{200, 1000, 10000, 50000, 200000};
+  }
+
+  private void delay() {
+    final Random random = ThreadLocalRandom.current();
+    double p = random.nextDouble();
+    int mod;
+    if (p < 0.9) {
+      mod = 0;
+    } else if (p < 0.99) {
+      mod = 1;
+    } else if (p < 0.9999) {
+      mod = 2;
+    } else {
+      mod = 3;
+    }
+    // this will make mod 3 pauses global
+    Lock lock = mod == 3 ? DB_ACCESS.writeLock() : DB_ACCESS.readLock();
+    if (mod == 3) {
+      System.out.println("OUCH");
+    }
+    lock.lock();
+    try {
+      final long baseDelayNs = MICROSECONDS.toNanos(delays[mod]);
+      final int delayRangeNs = (int) (MICROSECONDS.toNanos(delays[mod + 1]) - baseDelayNs);
+      final long delayNs = baseDelayNs + random.nextInt(delayRangeNs);
+      final long deadline = System.nanoTime() + delayNs;
+      do {
+        LockSupport.parkNanos(deadline - System.nanoTime());
+      } while (System.nanoTime() < deadline && !Thread.interrupted());
+    } finally {
+      lock.unlock();
+    }
+
+  }
+
+  /**
+   * Initialize any state for this DB. Called once per DB instance; there is one DB instance per client thread.
+   */
+  public void init() {
+    int i = 0;
+    for (String delay : getProperties().getProperty(SIMULATE_DELAY, SIMULATE_DELAY_DEFAULT).split(",")) {
+      delays[i++] = Long.parseLong(delay);
+    }
+  }
+
+  /**
+   * Read a record from the database. Each field/value pair from the result will be stored in a HashMap.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to read.
+   * @param fields The list of fields to read, or null for all of them
+   * @param result A HashMap of field/value pairs for the result
+   * @return Zero on success, a non-zero error code on error
+   */
+  public Status read(String table, String key, Set<String> fields, Map<String, ByteIterator> result) {
+    delay();
+    return Status.OK;
+  }
+
+  /**
+   * Perform a range scan for a set of records in the database. Each field/value pair from the result will be stored
+   * in a HashMap.
+   *
+   * @param table The name of the table
+   * @param startkey The record key of the first record to read.
+   * @param recordcount The number of records to read
+   * @param fields The list of fields to read, or null for all of them
+   * @param result A Vector of HashMaps, where each HashMap is a set field/value pairs for one record
+   * @return Zero on success, a non-zero error code on error
+   */
+  public Status scan(String table, String startkey, int recordcount, Set<String> fields,
+                     Vector<HashMap<String, ByteIterator>> result) {
+    delay();
+
+    return Status.OK;
+  }
+
+  /**
+   * Update a record in the database. Any field/value pairs in the specified values HashMap will be written into the
+   * record with the specified record key, overwriting any existing values with the same field name.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to write.
+   * @param values A HashMap of field/value pairs to update in the record
+   * @return Zero on success, a non-zero error code on error
+   */
+  public Status update(String table, String key, Map<String, ByteIterator> values) {
+    delay();
+
+    return Status.OK;
+  }
+
+  /**
+   * Insert a record in the database. Any field/value pairs in the specified values HashMap will be written into the
+   * record with the specified record key.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to insert.
+   * @param values A HashMap of field/value pairs to insert in the record
+   * @return Zero on success, a non-zero error code on error
+   */
+  public Status insert(String table, String key, Map<String, ByteIterator> values) {
+    delay();
+    return Status.OK;
+  }
+
+  /**
+   * Delete a record from the database.
+   *
+   * @param table The name of the table
+   * @param key The record key of the record to delete.
+   * @return Zero on success, a non-zero error code on error
+   */
+  public Status delete(String table, String key) {
+    delay();
+    return Status.OK;
+  }
+}

code/cppclient/YCSB/core/src/main/java/site/ycsb/NumericByteIterator.java

+/**
+ * Copyright (c) 2017 YCSB contributors. All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License"); you
+ * may not use this file except in compliance with the License. You
+ * may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
+ * implied. See the License for the specific language governing
+ * permissions and limitations under the License. See accompanying
+ * LICENSE file.
+ */
+package site.ycsb;
+
+/**
+ * A byte iterator that handles encoding and decoding numeric values.
+ * Currently this iterator can handle 64 bit signed values and double precision
+ * floating point values.
+ */
+public class NumericByteIterator extends ByteIterator {
+  private final byte[] payload;
+  private final boolean floatingPoint;
+  private int off;
+  
+  public NumericByteIterator(final long value) {
+    floatingPoint = false;
+    payload = Utils.longToBytes(value);
+    off = 0;
+  }
+  
+  public NumericByteIterator(final double value) {
+    floatingPoint = true;
+    payload = Utils.doubleToBytes(value);
+    off = 0;
+  }
+  
+  @Override
+  public boolean hasNext() {
+    return off < payload.length;
+  }
+
+  @Override
+  public byte nextByte() {
+    return payload[off++];
+  }
+
+  @Override
+  public long bytesLeft() {
+    return payload.length - off;
+  }
+
+  @Override
+  public void reset() {
+    off = 0;
+  }
+  
+  public long getLong() {
+    if (floatingPoint) {
+      throw new IllegalStateException("Byte iterator is of the type double");
+    }
+    return Utils.bytesToLong(payload);
+  }
+
+  public double getDouble() {
+    if (!floatingPoint) {
+      throw new IllegalStateException("Byte iterator is of the type long");
+    }
+    return Utils.bytesToDouble(payload);
+  }
+
+  public boolean isFloatingPoint() {
+    return floatingPoint;
+  }
+
+}
\ No newline at end of file