pg_archivecleanup
pg_archivecleanup — clean upPostgreSQL WAL archive files
Synopsis
pg_archivecleanup [option...]archivelocationoldestkeptwalfile
Description
pg_archivecleanup is designed to be used as anarchive_cleanup_command to clean up WAL file archives when running as a standby server (seeSection 26.2).pg_archivecleanup can also be used as a standalone program to clean WAL file archives.
To configure a standby server to usepg_archivecleanup, put this into itspostgresql.conf configuration file:
archive_cleanup_command = 'pg_archivecleanuparchivelocation %r' wherearchivelocation is the directory from which WAL segment files should be removed.
When used withinarchive_cleanup_command, all WAL files logically preceding the value of the%r argument will be removed fromarchivelocation. This minimizes the number of files that need to be retained, while preserving crash-restart capability. Use of this parameter is appropriate if thearchivelocation is a transient staging area for this particular standby server, butnot when thearchivelocation is intended as a long-term WAL archive area, or when multiple standby servers are recovering from the same archive location.
When used as a standalone program all WAL files logically preceding theoldestkeptwalfile will be removed fromarchivelocation. In this mode, if you specify a.partial or.backup file name, then only the file prefix will be used as theoldestkeptwalfile. This treatment of.backup file name allows you to remove all WAL files archived prior to a specific base backup without error. For example, the following example will remove all files older than WAL file name000000010000003700000010:
pg_archivecleanup -d archive 000000010000003700000010.00000020.backuppg_archivecleanup: keep WAL file "archive/000000010000003700000010" and laterpg_archivecleanup: removing file "archive/00000001000000370000000F"pg_archivecleanup: removing file "archive/00000001000000370000000E"
pg_archivecleanup assumes thatarchivelocation is a directory readable and writable by the server-owning user.
Options
pg_archivecleanup accepts the following command-line arguments:
-b--clean-backup-historyRemove backup history files as well. SeeSection 25.3.2 for details about backup history files.
-d--debugPrint lots of debug logging output on
stderr.-n--dry-runPrint the names of the files that would have been removed on
stdout(performs a dry run).-V--versionPrint thepg_archivecleanup version and exit.
-xextension--strip-extension=extensionProvide an extension that will be stripped from all file names before deciding if they should be deleted. This is typically useful for cleaning up archives that have been compressed during storage, and therefore have had an extension added by the compression program. For example:
-x .gz.-?--helpShow help aboutpg_archivecleanup command line arguments, and exit.
Environment
The environment variablePG_COLOR specifies whether to use color in diagnostic messages. Possible values arealways,auto andnever.
Notes
pg_archivecleanup is designed to work withPostgreSQL 8.0 and later when used as a standalone utility, or withPostgreSQL 9.0 and later when used as an archive cleanup command.
pg_archivecleanup is written in C and has an easy-to-modify source code, with specifically designated sections to modify for your own needs
Examples
On Linux or Unix systems, you might use:
archive_cleanup_command = 'pg_archivecleanup -d /mnt/standby/archive %r 2>>cleanup.log'
where the archive directory is physically located on the standby server, so that thearchive_command is accessing it across NFS, but the files are local to the standby. This will:
produce debugging output in
cleanup.logremove no-longer-needed files from the archive directory