You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

378 lines
9.9 KiB

/*
* pg_archivecleanup.c
*
* To be used as archive_cleanup_command to clean an archive when using
* standby mode.
*
* src/bin/pg_archivecleanup/pg_archivecleanup.c
*/
#include "postgres_fe.h"
#include <ctype.h>
#include <dirent.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <signal.h>
#include <sys/time.h>
#include "access/xlog_internal.h"
#include "common/logging.h"
#include "pg_getopt.h"
const char *progname;
/* Options and defaults */
bool dryrun = false; /* are we performing a dry-run operation? */
char *additional_ext = NULL; /* Extension to remove from filenames */
char *archiveLocation; /* where to find the archive? */
char *restartWALFileName; /* the file from which we can restart restore */
char exclusiveCleanupFileName[MAXFNAMELEN]; /* 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
* encouraged to submit any changes to pgsql-hackers@lists.postgresql.org
* or personally to the current maintainer. Those changes may be
* folded in to later versions of this program.
*/
/*
* 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))
{
pg_log_error("archive location \"%s\" does not exist",
archiveLocation);
exit(2);
}
}
static void
TrimExtension(char *filename, char *extension)
{
int flen;
int elen;
if (extension == NULL)
return;
elen = strlen(extension);
flen = strlen(filename);
if (flen > elen && strcmp(filename + flen - elen, extension) == 0)
filename[flen - elen] = '\0';
}
static void
CleanupPriorWALFiles(void)
{
int rc;
DIR *xldir;
struct dirent *xlde;
char walfile[MAXPGPATH];
if ((xldir = opendir(archiveLocation)) != NULL)
{
while (errno = 0, (xlde = readdir(xldir)) != NULL)
{
/*
* Truncation is essentially harmless, because we skip names of
* length other than XLOG_FNAME_LEN. (In principle, one could use
* a 1000-character additional_ext and get trouble.)
*/
strlcpy(walfile, xlde->d_name, MAXPGPATH);
TrimExtension(walfile, additional_ext);
/*
* 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 ((IsXLogFileName(walfile) || IsPartialXLogFileName(walfile)) &&
strcmp(walfile + 8, exclusiveCleanupFileName + 8) < 0)
{
char WALFilePath[MAXPGPATH * 2]; /* the file path
* including archive */
/*
* Use the original file name again now, including any
* extension that might have been chopped off before testing
* the sequence.
*/
snprintf(WALFilePath, sizeof(WALFilePath), "%s/%s",
archiveLocation, xlde->d_name);
if (dryrun)
{
/*
* Prints the name of the file to be removed and skips the
* actual removal. The regular printout is so that the
* user can pipe the output into some other program.
*/
printf("%s\n", WALFilePath);
pg_log_debug("file \"%s\" would be removed", WALFilePath);
continue;
}
pg_log_debug("removing file \"%s\"", WALFilePath);
rc = unlink(WALFilePath);
if (rc != 0)
{
pg_log_error("could not remove file \"%s\": %m",
WALFilePath);
break;
}
}
}
if (errno)
pg_log_error("could not read archive location \"%s\": %m",
archiveLocation);
if (closedir(xldir))
pg_log_error("could not close archive location \"%s\": %m",
archiveLocation);
}
else
pg_log_error("could not open archive location \"%s\": %m",
archiveLocation);
}
/*
* 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;
TrimExtension(restartWALFileName, additional_ext);
/*
* If restartWALFileName is a WAL file name then just use it directly. If
* restartWALFileName is a .partial or .backup filename, make sure we use
* the prefix of the filename, otherwise we will remove wrong files since
* 000000010000000000000010.partial and
* 000000010000000000000010.00000020.backup are after
* 000000010000000000000010.
*/
if (IsXLogFileName(restartWALFileName))
{
strcpy(exclusiveCleanupFileName, restartWALFileName);
fnameOK = true;
}
else if (IsPartialXLogFileName(restartWALFileName))
{
int args;
uint32 tli = 1,
log = 0,
seg = 0;
args = sscanf(restartWALFileName, "%08X%08X%08X.partial",
&tli, &log, &seg);
if (args == 3)
{
fnameOK = true;
/*
* Use just the prefix of the filename, ignore everything after
* first period
*/
XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
}
}
else if (IsBackupHistoryFileName(restartWALFileName))
{
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
*/
XLogFileNameById(exclusiveCleanupFileName, tli, log, seg);
}
}
if (!fnameOK)
{
pg_log_error("invalid file name argument");
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 generate debug output (verbose mode)\n"));
printf(_(" -n dry run, show the names of the files that would be removed\n"));
printf(_(" -V, --version output version information, then exit\n"));
printf(_(" -x EXT clean up files if they have this extension\n"));
printf(_(" -?, --help show this help, then exit\n"));
printf(_("\n"
"For use as archive_cleanup_command in postgresql.conf:\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 <%s>.\n"), PACKAGE_BUGREPORT);
printf(_("%s home page: <%s>\n"), PACKAGE_NAME, PACKAGE_URL);
}
/*------------ MAIN ----------------------------------------*/
int
main(int argc, char **argv)
{
int c;
pg_logging_init(argv[0]);
set_pglocale_pgservice(argv[0], PG_TEXTDOMAIN("pg_archivecleanup"));
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, "x:dn")) != -1)
{
switch (c)
{
case 'd': /* Debug mode */
pg_logging_set_level(PG_LOG_DEBUG);
break;
case 'n': /* Dry-Run mode */
dryrun = true;
break;
case 'x':
additional_ext = pg_strdup(optarg); /* Extension to remove
* from xlogfile names */
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
{
pg_log_error("must specify archive location");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(2);
}
if (optind < argc)
{
restartWALFileName = argv[optind];
optind++;
}
else
{
pg_log_error("must specify oldest kept WAL file");
fprintf(stderr, _("Try \"%s --help\" for more information.\n"), progname);
exit(2);
}
if (optind < argc)
{
pg_log_error("too many command-line arguments");
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();
pg_log_debug("keeping WAL file \"%s/%s\" and later",
archiveLocation, exclusiveCleanupFileName);
/*
* Remove WAL files older than cut-off
*/
CleanupPriorWALFiles();
exit(0);
}