|
|
|
|
@ -6,9 +6,9 @@ |
|
|
|
|
</indexterm> |
|
|
|
|
|
|
|
|
|
<para> |
|
|
|
|
<literal>pg_standby</literal> is a production-ready program that can be used |
|
|
|
|
to create a Warm Standby server. Other configuration is required as well, |
|
|
|
|
all of which is described in the main server manual. |
|
|
|
|
<literal>pg_standby</literal> allows the creation of a Warm Standby server. |
|
|
|
|
Other configuration is required as well, all of which is described in the |
|
|
|
|
main server manual. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
The program is designed to be a wait-for <literal>restore_command</literal>, |
|
|
|
|
@ -17,7 +17,7 @@ |
|
|
|
|
you could configure <literal>pg_standby</literal> in the following way: |
|
|
|
|
</para> |
|
|
|
|
<programlisting> |
|
|
|
|
restore_command = 'pg_standby archiveDir %f %p' |
|
|
|
|
restore_command = 'pg_standby archiveDir %f %p %r' |
|
|
|
|
</programlisting> |
|
|
|
|
<para> |
|
|
|
|
which would be sufficient to define that files will be restored from |
|
|
|
|
@ -71,12 +71,24 @@ |
|
|
|
|
with the pg_standby command usage as |
|
|
|
|
</para> |
|
|
|
|
<programlisting> |
|
|
|
|
pg_standby [OPTION]... [ARCHIVELOCATION] [NEXTWALFILE] [XLOGFILEPATH] |
|
|
|
|
pg_standby [OPTION]... ARCHIVELOCATION NEXTWALFILE XLOGFILEPATH [RESTARTWALFILE] |
|
|
|
|
</programlisting> |
|
|
|
|
<para> |
|
|
|
|
When used within the <literal>restore_command</literal> the %f and %p macros |
|
|
|
|
will provide the actual file and path required for the restore/recovery. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
<literal>pg_standby</literal> assumes that <literal>ARCHIVELOCATION</literal> |
|
|
|
|
is a directory accessible by the server-owning user. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
If <literal>RESTARTWALFILE</literal> is specified, typically by using the |
|
|
|
|
<literal>%r</literal> option, then all files prior to this file will be |
|
|
|
|
removed from <literal>ARCHIVELOCATION</literal>. This then minimises the |
|
|
|
|
number of files that need to be held, whilst at the same time maintaining |
|
|
|
|
restart capability. This capability additionally assumes that |
|
|
|
|
<literal>ARCHIVELOCATION</literal> directory is writable. |
|
|
|
|
</para> |
|
|
|
|
|
|
|
|
|
<table> |
|
|
|
|
<title>Options</title> |
|
|
|
|
@ -94,8 +106,11 @@ |
|
|
|
|
<entry>-k numfiles</entry> |
|
|
|
|
<entry> |
|
|
|
|
<para> |
|
|
|
|
Cleanup files in the archive so that we maintain no more |
|
|
|
|
than this many files in the archive. |
|
|
|
|
Cleanup files in the archive so that we maintain no more than this |
|
|
|
|
many files in the archive. This parameter will be silently ignored if |
|
|
|
|
<literal>RESTARTWALFILE</literal> is specified, since that |
|
|
|
|
specification method is more accurate in determining the correct |
|
|
|
|
cut-off point in archive. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
You should be wary against setting this number too low, |
|
|
|
|
@ -108,9 +123,17 @@ |
|
|
|
|
It is wholly unrelated to the setting of checkpoint_segments |
|
|
|
|
on either primary or standby. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
Setting <literal>numfiles</literal> to be zero will disable deletion |
|
|
|
|
of files from <literal>ARCHIVELOCATION</literal>. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
If in doubt, use a large value or do not set a value at all. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
If you specify neither <literal>RESTARTWALFILE</> nor <literal>-k</>, |
|
|
|
|
then <literal>-k 0</> will be assumed, i.e. keep all files in archive. |
|
|
|
|
</para> |
|
|
|
|
</entry> |
|
|
|
|
</row> |
|
|
|
|
<row> |
|
|
|
|
@ -121,9 +144,10 @@ |
|
|
|
|
WAL files will remain in archive |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
Link is more efficient, but the default is copy to |
|
|
|
|
allow you to maintain the WAL archive for recovery |
|
|
|
|
purposes as well as high-availability. |
|
|
|
|
Link is more efficient, but the default is copy to allow you to |
|
|
|
|
maintain the WAL archive for recovery purposes as well as |
|
|
|
|
high-availability. The default setting is not necessarily recommended, |
|
|
|
|
consult the main database server manual for discussion. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
This option uses the Windows Vista command mklink |
|
|
|
|
@ -144,7 +168,7 @@ |
|
|
|
|
we will wait 5 secs, 10 secs then 15 secs before reporting |
|
|
|
|
the failure back to the database server. This will be |
|
|
|
|
interpreted as and end of recovery and the Standby will come |
|
|
|
|
up fully as a result. <literal>Default=3</literal> |
|
|
|
|
up fully as a result. <literal>Default=3 Min=0</literal> |
|
|
|
|
</para> |
|
|
|
|
</entry> |
|
|
|
|
</row> |
|
|
|
|
@ -155,7 +179,7 @@ |
|
|
|
|
if the file to be restored is available in the archive yet. |
|
|
|
|
The default setting is not necessarily recommended, |
|
|
|
|
consult the main database server manual for discussion. |
|
|
|
|
<literal>Default=5</literal> |
|
|
|
|
<literal>Default=5, Min=1, Max=60</literal> |
|
|
|
|
</entry> |
|
|
|
|
</row> |
|
|
|
|
<row> |
|
|
|
|
@ -175,8 +199,9 @@ |
|
|
|
|
the maximum number of seconds to wait for the next file, |
|
|
|
|
after which recovery will end and the Standby will come up. |
|
|
|
|
The default setting is not necessarily recommended, |
|
|
|
|
consult the main database server manual for discussion. |
|
|
|
|
<literal>Default=0</literal> |
|
|
|
|
consult the main database server manual for discussion. A setting of |
|
|
|
|
zero means wait forever. |
|
|
|
|
<literal>Default=0, Min=0</literal> |
|
|
|
|
</entry> |
|
|
|
|
</row> |
|
|
|
|
</tbody> |
|
|
|
|
@ -191,6 +216,32 @@ |
|
|
|
|
</note> |
|
|
|
|
</sect2> |
|
|
|
|
|
|
|
|
|
<sect2> |
|
|
|
|
<title>Supported versions</title> |
|
|
|
|
<para> |
|
|
|
|
<literal>pg_standby</literal> is designed to work with PostgreSQL 8.2 and |
|
|
|
|
and later. It is currently compatible across minor changes between the way |
|
|
|
|
8.3 and 8.2 operate. |
|
|
|
|
</para> |
|
|
|
|
<para> |
|
|
|
|
PostgreSQL 8.3 provides the <literal>%r</literal> command line substitution, |
|
|
|
|
designed to let <literal>pg_standby</literal> know the last file it needs to |
|
|
|
|
keep. If the last parameter is omitted, no error is generated, allowing |
|
|
|
|
<literal>pg_standby</literal> to function correctly with PostgreSQL 8.2 |
|
|
|
|
also. With PostgreSQL 8.2, the <literal>-k</literal> option must be used if |
|
|
|
|
archive cleanup is required. This option remains available in 8.3. |
|
|
|
|
</para> |
|
|
|
|
</sect2> |
|
|
|
|
|
|
|
|
|
<sect2> |
|
|
|
|
<title>Additional design notes</title> |
|
|
|
|
<para> |
|
|
|
|
The use of a move command seems like it would be a good idea, but this would |
|
|
|
|
prevent recovery from being restartable. Also, the last WAL file is always |
|
|
|
|
requested twice from the archive. |
|
|
|
|
</para> |
|
|
|
|
</sect2> |
|
|
|
|
|
|
|
|
|
<sect2> |
|
|
|
|
<title>Examples</title> |
|
|
|
|
|
|
|
|
|
@ -227,8 +278,7 @@ archive_command = 'copy %p ..\\archive\\%f' |
|
|
|
|
*not* in the restore_command, in 8.2, 8.1, 8.0 on Windows. |
|
|
|
|
</para> |
|
|
|
|
<programlisting> |
|
|
|
|
restore_command = 'pg_standby -c -d -s 5 -w 0 -t C:\pgsql.trigger.5442 |
|
|
|
|
..\archive %f %p 2>> standby.log' |
|
|
|
|
restore_command = 'pg_standby -c -d -s 5 -w 0 -t C:\pgsql.trigger.5442 ..\archive %f %p 2>> standby.log' |
|
|
|
|
</programlisting> |
|
|
|
|
<para> |
|
|
|
|
which will |
|
|
|
|
|
Tom Lane
18 years ago