Files for pg_archivecleanup

contrib/pg_archivecleanup/Makefile

+# $PostgreSQL: pgsql/contrib/pg_archivecleanup/Makefile,v 1.1 2010/06/14 16:19:24 sriggs Exp $
+
+PGFILEDESC = "pg_archivecleanup - cleans archive when used with streaming replication"
+PGAPPICON=win32
+
+PROGRAM = pg_archivecleanup
+OBJS	= pg_archivecleanup.o
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/pg_archivecleanup
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif

contrib/pg_archivecleanup/pg_archivecleanup.c

+/*
+ * $PostgreSQL: pgsql/contrib/pg_archivecleanup/pg_archivecleanup.c,v 1.1 2010/06/14 16:19:24 sriggs Exp $
+ *
+ * pg_archivecleanup.c
+ *
+ * Production-ready example of an archive_cleanup_command
+ * used to clean an archive when using standby_mode = on in 9.0
+ * or for standalone use for any version of PostgreSQL 8.0+.
+ *
+ * Original author:		Simon Riggs  simon@2ndquadrant.com
+ * Current maintainer:	Simon Riggs
+ */
+#include "postgres_fe.h"
+
+#include <ctype.h>
+#include <dirent.h>
+#include <sys/stat.h>
+#include <fcntl.h>
+#include <signal.h>
+
+#ifdef WIN32
+int			getopt(int argc, char *const argv[], const char *optstring);
+#else
+#include <sys/time.h>
+#include <unistd.h>
+
+#ifdef HAVE_GETOPT_H
+#include <getopt.h>
+#endif
+#endif   /* ! WIN32 */
+
+extern char *optarg;
+extern int	optind;
+
+const char *progname;
+
+/* Options and defaults */
+bool		debug = false;		/* are we debugging? */
+
+char	   *archiveLocation;	/* where to find the archive? */
+char	   *restartWALFileName; /* the file from which we can restart restore */
+char		WALFilePath[MAXPGPATH];		/* the file path including archive */
+char		exclusiveCleanupFileName[MAXPGPATH];		/* the oldest file we want to
+														 * remain in archive */
+
+struct stat stat_buf;
+
+/* =====================================================================
+ *
+ *		  Customizable section
+ *
+ * =====================================================================
+ *
+ *	Currently, this section assumes that the Archive is a locally
+ *	accessible directory. If you want to make other assumptions,
+ *	such as using a vendor-specific archive and access API, these
+ *	routines are the ones you'll need to change. You're
+ *	enouraged to submit any changes to pgsql-hackers@postgresql.org
+ *	or personally to the current maintainer. Those changes may be
+ *	folded in to later versions of this program.
+ */
+
+#define XLOG_DATA_FNAME_LEN		24
+/* Reworked from access/xlog_internal.h */
+#define XLogFileName(fname, tli, log, seg)	\
+	snprintf(fname, XLOG_DATA_FNAME_LEN + 1, "%08X%08X%08X", tli, log, seg)
+#define XLOG_BACKUP_FNAME_LEN	40
+
+/*
+ *	Initialize allows customized commands into the archive cleanup program.
+ *
+ *  You may wish to add code to check for tape libraries, etc..
+ */
+static void
+Initialize(void)
+{
+	/*
+	 * This code assumes that archiveLocation is a directory, so we use
+	 * stat to test if it's accessible.
+	 */
+	if (stat(archiveLocation, &stat_buf) != 0)
+	{
+		fprintf(stderr, "%s: archiveLocation \"%s\" does not exist\n", progname, archiveLocation);
+		fflush(stderr);
+		exit(2);
+	}
+}
+
+static void
+CleanupPriorWALFiles(void)
+{
+	int			rc;
+	DIR		   *xldir;
+	struct dirent *xlde;
+
+	if ((xldir = opendir(archiveLocation)) != NULL)
+	{
+		while ((xlde = readdir(xldir)) != NULL)
+		{
+			/*
+			 * We ignore the timeline part of the XLOG segment identifiers
+			 * in deciding whether a segment is still needed.  This
+			 * ensures that we won't prematurely remove a segment from a
+			 * parent timeline. We could probably be a little more
+			 * proactive about removing segments of non-parent timelines,
+			 * but that would be a whole lot more complicated.
+			 *
+			 * We use the alphanumeric sorting property of the filenames
+			 * to decide which ones are earlier than the
+			 * exclusiveCleanupFileName file. Note that this means files
+			 * are not removed in the order they were originally written,
+			 * in case this worries you.
+			 */
+			if (strlen(xlde->d_name) == XLOG_DATA_FNAME_LEN &&
+				strspn(xlde->d_name, "0123456789ABCDEF") == XLOG_DATA_FNAME_LEN &&
+			  strcmp(xlde->d_name + 8, exclusiveCleanupFileName + 8) < 0)
+			{
+#ifdef WIN32
+				snprintf(WALFilePath, MAXPGPATH, "%s\\%s", archiveLocation, xlde->d_name);
+#else
+				snprintf(WALFilePath, MAXPGPATH, "%s/%s", archiveLocation, xlde->d_name);
+#endif
+
+				if (debug)
+					fprintf(stderr, "\n%s:  removing \"%s\"", progname, WALFilePath);
+
+				rc = unlink(WALFilePath);
+				if (rc != 0)
+				{
+					fprintf(stderr, "\n%s: ERROR failed to remove \"%s\": %s",
+							progname, WALFilePath, strerror(errno));
+					break;
+				}
+			}
+		}
+		if (debug)
+			fprintf(stderr, "\n");
+	}
+	else
+		fprintf(stderr, "%s: archiveLocation \"%s\" open error\n", progname, archiveLocation);
+
+	closedir(xldir);
+	fflush(stderr);
+}
+
+/*
+ * SetWALFileNameForCleanup()
+ *
+ *	  Set the earliest WAL filename that we want to keep on the archive
+ *	  and decide whether we need_cleanup
+ */
+static void
+SetWALFileNameForCleanup(void)
+{
+	bool	fnameOK = false;
+
+	/*
+	 * If restartWALFileName is a WAL file name then just use it directly.
+	 * If restartWALFileName is a .backup filename, make sure we use
+	 * the prefix of the filename, otherwise we will remove wrong files
+	 * since 000000010000000000000010.00000020.backup is after 
+	 * 000000010000000000000010.
+	 */
+	if (strlen(restartWALFileName) == XLOG_DATA_FNAME_LEN &&
+		strspn(restartWALFileName, "0123456789ABCDEF") == XLOG_DATA_FNAME_LEN)
+	{
+		strcpy(exclusiveCleanupFileName, restartWALFileName);
+		fnameOK = true;
+	}
+	else if (strlen(restartWALFileName) == XLOG_BACKUP_FNAME_LEN)
+	{
+		int	args;
+		uint32		tli = 1,
+					log = 0,
+					seg = 0,
+					offset = 0;
+		args = sscanf(restartWALFileName, "%08X%08X%08X.%08X.backup", &tli, &log, &seg, &offset);
+		if (args == 4)
+		{
+			fnameOK = true;
+			/*
+			 * Use just the prefix of the filename, ignore everything after first period
+			 */
+			XLogFileName(exclusiveCleanupFileName, tli, log, seg);
+		}
+	}
+
+	if (!fnameOK)
+	{
+		fprintf(stderr, "%s: invalid filename input\n", progname);
+		fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
+		exit(2);
+	}
+}
+
+/* =====================================================================
+ *		  End of Customizable section
+ * =====================================================================
+ */
+
+static void
+usage(void)
+{
+	printf("%s removes older WAL files from PostgreSQL archives.\n\n", progname);
+	printf("Usage:\n");
+	printf("  %s [OPTION]... ARCHIVELOCATION OLDESTKEPTWALFILE\n", progname);
+	printf("\n"
+		"for use as an archive_cleanup_command in the recovery.conf when standby_mode = on:\n"
+		   "  archive_cleanup_command = 'pg_archivecleanup [OPTION]... ARCHIVELOCATION %%r'\n"
+		   "e.g.\n"
+		   "  archive_cleanup_command = 'pg_archivecleanup /mnt/server/archiverdir %%r'\n");
+	printf("\n"
+		"or for use as a standalone archive cleaner:\n"
+		   "e.g.\n"
+		   "  pg_archivecleanup /mnt/server/archiverdir 000000010000000000000010.00000020.backup\n");
+	printf("\nOptions:\n");
+	printf("  -d                 generates debug output (verbose mode)\n");
+	printf("  --help             show this help, then exit\n");
+	printf("  --version          output version information, then exit\n");
+	printf("\nReport bugs to <pgsql-bugs@postgresql.org>.\n");
+}
+
+/*------------ MAIN ----------------------------------------*/
+int
+main(int argc, char **argv)
+{
+	int			c;
+
+	progname = get_progname(argv[0]);
+
+	if (argc > 1)
+	{
+		if (strcmp(argv[1], "--help") == 0 || strcmp(argv[1], "-?") == 0)
+		{
+			usage();
+			exit(0);
+		}
+		if (strcmp(argv[1], "--version") == 0 || strcmp(argv[1], "-V") == 0)
+		{
+			puts("pg_archivecleanup (PostgreSQL) " PG_VERSION);
+			exit(0);
+		}
+	}
+
+	while ((c = getopt(argc, argv, "d")) != -1)
+	{
+		switch (c)
+		{
+			case 'd':			/* Debug mode */
+				debug = true;
+				break;
+			default:
+				fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
+				exit(2);
+				break;
+		}
+	}
+
+	/*
+	 * We will go to the archiveLocation to check restartWALFileName.
+	 * restartWALFileName may not exist anymore, which would not be an error, so
+	 * we separate the archiveLocation and restartWALFileName so we can check
+	 * separately whether archiveLocation exists, if not that is an error
+	 */
+	if (optind < argc)
+	{
+		archiveLocation = argv[optind];
+		optind++;
+	}
+	else
+	{
+		fprintf(stderr, "%s: must specify archive location\n", progname);
+		fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
+		exit(2);
+	}
+
+	if (optind < argc)
+	{
+		restartWALFileName = argv[optind];
+		optind++;
+	}
+	else
+	{
+		fprintf(stderr, "%s: must specify restartfilename\n", progname);
+		fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
+		exit(2);
+	}
+
+	if (optind < argc)
+	{
+		fprintf(stderr, "%s: too many parameters\n", progname);
+		fprintf(stderr, "Try \"%s --help\" for more information.\n", progname);
+		exit(2);
+	}
+
+	/*
+	 * Check archive exists and other initialization if required.
+	 */
+	Initialize();
+
+	/*
+	 * Check filename is a valid name, then process to find cut-off
+	 */
+	SetWALFileNameForCleanup();
+
+	if (debug)
+	{
+		fprintf(stderr, "%s:  keep WAL file %s and later", progname, exclusiveCleanupFileName);
+		fflush(stderr);
+	}
+
+	/*
+	 * Remove WAL files older than cut-off
+	 */
+	CleanupPriorWALFiles();
+
+	exit(0);
+}