pg_archivecleanup — 清理 PostgreSQL WAL 歸檔檔案
To configure a standby server to use pg_archivecleanup, put this into its
archive_cleanup_command = 'pg_archivecleanup archivelocation %r'
archivelocationis the directory from which WAL segment files should be removed.
When used within archive_cleanup_command, all WAL files logically preceding the value of the
%rargument will be removed from
archivelocation. This minimizes the number of files that need to be retained, while preserving crash-restart capability. Use of this parameter is appropriate if the
archivelocationis a transient staging area for this particular standby server, but not when the
archivelocationis 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 the
oldestkeptwalfilewill be removed from
archivelocation. In this mode, if you specify a
.backupfile name, then only the file prefix will be used as the
oldestkeptwalfile. This treatment of
.backupfile 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 name
pg_archivecleanup -d archive 000000010000003700000010.00000020.backup
pg_archivecleanup: keep WAL file "archive/000000010000003700000010" and later
pg_archivecleanup: removing file "archive/00000001000000370000000F"
pg_archivecleanup: removing file "archive/00000001000000370000000E"
pg_archivecleanup assumes that
archivelocationis a directory readable and writable by the server-owning user.
pg_archivecleanup accepts the following command-line arguments:
Print lots of debug logging output on
Print the names of the files that would have been removed on
stdout(performs a dry run).
Print the pg_archivecleanup version and exit.
Provide 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:
Show help about pg_archivecleanup command line arguments, and exit.
The environment variable
PG_COLORspecifies whether to use color in diagnostic messages. Possible values are
pg_archivecleanup is designed to work with PostgreSQL 8.0 and later when used as a standalone utility, or with PostgreSQL 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
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 the
archive_commandis accessing it across NFS, but the files are local to the standby. This will:
- produce debugging output in
- remove no-longer-needed files from the archive directory