Added random read from replicaset

code/hpdos_client/app.config

 app.name="HPDOS-Client"
 app.version="0.1.4"
 app.thread_count=12
-app.runtime=15
+app.runtime=30
 app.cycle_create=1
 app.cycle_read=4
 app.cycle_update=3

code/hpdos_client/app/src/main/proto/PacketFormat.proto

@@ -14,6 +14,7 @@ service NetworkService {
   rpc createMetadata(Packet) returns (Packet) {}
   rpc updateMetadata(Packet) returns (Packet) {}
   rpc deleteMetadata(Packet) returns (Packet) {}
+  rpc getReadReplicaList(RequestList) returns (ResponseList) {}
 }
 
 
@@ -53,4 +54,19 @@ message Ack {
 message Nack {
   string key = 2;
   int32 version = 3;
+}
+
+message RequestList {}
+
+message ResponseList {
+  int32 operationType = 1;
+  int32 status = 2;
+  repeated Follower follower = 3;
+}
+
+message Follower {
+  string ip = 1;
+  int32 port = 2;
+  string followerID = 3;
+  int64 lastSeen = 4;
 }
\ No newline at end of file

code/hpdos_server/app/src/main/java/hpdos/handler/NetworkHandler.java

@@ -2,12 +2,14 @@ package hpdos.handler;
 
 import com.google.common.base.Stopwatch;
 import hpdos.grpc.*;
+import hpdos.lib.MasterFollower;
 import hpdos.lib.ReplicationService;
 import hpdos.message.RequestBuilder;
 import hpdos.message.ResponseBuilder;
 import io.grpc.stub.StreamObserver;
 
 import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.concurrent.ExecutionException;
 
 public class NetworkHandler extends NetworkServiceGrpc.NetworkServiceImplBase {
@@ -75,6 +77,24 @@ public class NetworkHandler extends NetworkServiceGrpc.NetworkServiceImplBase {
         responseObserver.onCompleted();
     }
 
+    @Override
+    public void getReadReplicaList(RequestList requestList,
+                                   StreamObserver<ResponseList> responseListStreamObserver) {
+        HashMap<String, MasterFollower> followers = replicationService.getFollowers();
+        ResponseList.Builder responseList = ResponseList.newBuilder();
+        for (MasterFollower follower: followers.values()) {
+            Follower.Builder replica = Follower.newBuilder();
+            replica.setIp(follower.getIp());
+            replica.setPort(follower.getPort());
+            replica.setFollowerID(follower.getFollowerID());
+            replica.setLastSeen(follower.getLastSeen());
+            replica.build();
+            responseList.addFollower(replica);
+        }
+        responseListStreamObserver.onNext(responseList.build());
+        responseListStreamObserver.onCompleted();
+    }
+
     private Packet replicate(Packet requestPacket) {
         ReplicationRequest replicationRequest = RequestBuilder.
                 buildReplicationRequest(new ArrayList<>(requestPacket.getRequestList()));

code/hpdos_server/app/src/main/java/hpdos/lib/InlineReplicationService.java

@@ -104,6 +104,11 @@ public class InlineReplicationService implements ReplicationService {
             ListenableFuture<ReplicationResponse> res = stub.replicateMetadata(replicationRequest);
 
         }
-        return null;
+        throw new UnsupportedOperationException("Implementation not complete");
+    }
+
+    @Override
+    public HashMap<String, MasterFollower> getFollowers() {
+        return followers;
     }
 }

code/hpdos_server/app/src/main/java/hpdos/lib/ReplicationService.java

@@ -3,10 +3,12 @@ package hpdos.lib;
 import hpdos.grpc.ReplicationRequest;
 import hpdos.grpc.ReplicationResponse;
 
+import java.util.HashMap;
 import java.util.concurrent.ExecutionException;
 
 public interface ReplicationService {
     abstract ReplicationResponse replicateMetadata(ReplicationRequest replicationRequest) throws InterruptedException, ExecutionException;
     abstract ReplicationResponse replicateMetadataAsync(ReplicationRequest replicationRequest);
     abstract void cleanup() throws InterruptedException;
+    abstract HashMap<String, MasterFollower> getFollowers();
 }

code/hpdos_server/app/src/main/proto/PacketFormat.proto

@@ -14,6 +14,7 @@ service NetworkService {
     rpc createMetadata(Packet) returns (Packet) {}
     rpc updateMetadata(Packet) returns (Packet) {}
     rpc deleteMetadata(Packet) returns (Packet) {}
+    rpc getReadReplicaList(RequestList) returns (ResponseList) {}
 }
 
 
@@ -53,4 +54,19 @@ message Ack {
 message Nack {
     string key = 2;
     int32 version = 3;
+}
+
+message RequestList {}
+
+message ResponseList {
+    int32 operationType = 1;
+    int32 status = 2;
+    repeated Follower follower = 3;
+}
+
+message Follower {
+    string ip = 1;
+    int32 port = 2;
+    string followerID = 3;
+    int64 lastSeen = 4;
 }
\ No newline at end of file