pg_archivecleanup
pg_archivecleanup
pg_archivecleanup - clean up PostgreSQL WAL archive files
Synopsis
pg_archivecleanup
[
option
...]
archivelocation
oldestkeptwalfile
Description
pg_archivecleanup
is designed to be used as an
archive_cleanup_command
to clean up WAL file archives when
running as a standby server (see
Section 26.2
).
pg_archivecleanup
can also be used as a standalone program to
clean WAL file archives.
To configure a standby
server to use
pg_archivecleanup
, put this into its
postgresql.conf
configuration file:
archive_cleanup_command = 'pg_archivecleanup archivelocation %r'
where
archivelocation
is 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
%r
argument 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
archivelocation
is a
transient staging area for this particular standby server, but
not
when the
archivelocation
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 the
oldestkeptwalfile
will be removed from
archivelocation
.
In this mode, if you specify a
.partial
or
.backup
file name, then only the file prefix will be used as the
oldestkeptwalfile
. 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 name
000000010000003700000010
:
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
archivelocation
is a directory readable and writable by the
server-owning user.
Options
pg_archivecleanup accepts the following command-line arguments:
-
-b
--clean-backup-history -
Remove backup history files as well. See Section 25.3.2 for details about backup history files.
-
-d
--debug -
Print lots of debug logging output on
stderr. -
-n
--dry-run -
Print the names of the files that would have been removed on
stdout(performs a dry run). -
-V
--version -
Print the pg_archivecleanup version and exit.
-
-xextension
--strip-extension=extension -
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:
-x .gz. -
-?
--help -
Show help about pg_archivecleanup command line arguments, and exit.
Environment
The environment variable
PG_COLOR
specifies whether to use
color in diagnostic messages. Possible values are
always
,
auto
and
never
.
Notes
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
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 the
archive_command
is accessing it across NFS,
but the files are local to the standby.
This will:
-
produce debugging output in
cleanup.log -
remove no-longer-needed files from the archive directory