/* * contrib/pg_archivecleanup/pg_archivecleanup.c * * 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 #include #include #include #include #ifndef WIN32 #include #include #ifdef HAVE_GETOPT_H #include #endif #else /* WIN32 */ extern int getopt(int argc, char *const argv[], const char *optstring); #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 */ /* ===================================================================== * * 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. */ struct stat stat_buf; if (stat(archiveLocation, &stat_buf) != 0 || !S_ISDIR(stat_buf.st_mode)) { fprintf(stderr, "%s: archive location \"%s\" does not exist\n", progname, archiveLocation); 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) { snprintf(WALFilePath, MAXPGPATH, "%s/%s", archiveLocation, xlde->d_name); if (debug) fprintf(stderr, "%s: removing file \"%s\"\n", progname, WALFilePath); rc = unlink(WALFilePath); if (rc != 0) { fprintf(stderr, "%s: ERROR: could not remove file \"%s\": %s\n", progname, WALFilePath, strerror(errno)); break; } } } closedir(xldir); } else fprintf(stderr, "%s: could not open archive location \"%s\": %s\n", progname, archiveLocation, strerror(errno)); } /* * 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("\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("\n" "For use as archive_cleanup_command in 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("\nReport bugs to .\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) { snprintf(WALFilePath, MAXPGPATH, "%s/%s", archiveLocation, exclusiveCleanupFileName); fprintf(stderr, "%s: keep WAL file \"%s\" and later\n", progname, WALFilePath); } /* * Remove WAL files older than cut-off */ CleanupPriorWALFiles(); exit(0); }