Following the removal of pg_standby, also remove the documentation
section that describes how to write your own "waiting restore_command"
along the same lines.
Discussion: https://postgr.es/m/20201029024412.GP5380%40telsasoft.com
Reviewed-by: Michael Paquier <michael@paquier.xyz>
pg_standby was useful more than a decade ago, but now it is obsolete.
It has been proposed that we retire it many times. Now seems like a
good time to finally do it, because "waiting restore commands"
are incompatible with a proposed recovery prefetching feature.
Discussion: https://postgr.es/m/20201029024412.GP5380%40telsasoft.com
Author: Justin Pryzby <pryzby@telsasoft.com>
Reviewed-by: Heikki Linnakangas <hlinnaka@iki.fi>
Reviewed-by: Peter Eisentraut <peter.eisentraut@enterprisedb.com>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Fujii Masao <masao.fujii@oss.nttdata.com>
When certain parameters are changed on a physical replication primary,
this is communicated to standbys using the XLOG_PARAMETER_CHANGE WAL
record. The standby then checks whether its own settings are at least
as big as the ones on the primary. If not, the standby shuts down
with a fatal error.
This patch changes this behavior for hot standbys to pause recovery at
that point instead. That allows read traffic on the standby to
continue while database administrators figure out next steps. When
recovery is unpaused, the server shuts down (as before). The idea is
to fix the parameters while recovery is paused and then restart when
there is a maintenance window.
Reviewed-by: Sergei Kornilov <sk@zsrv.org>
Discussion: https://www.postgresql.org/message-id/flat/4ad69a4c-cc9b-0dfe-0352-8b1b0cd36c7b@2ndquadrant.com
This commit adds GUC log_recovery_conflict_waits that controls whether
a log message is produced when the startup process is waiting longer than
deadlock_timeout for recovery conflicts. This is useful in determining
if recovery conflicts prevent the recovery from applying WAL.
Note that currently a log message is produced only when recovery conflict
has not been resolved yet even after deadlock_timeout passes, i.e.,
only when the startup process is still waiting for recovery conflict
even after deadlock_timeout.
Author: Bertrand Drouvot, Masahiko Sawada
Reviewed-by: Alvaro Herrera, Kyotaro Horiguchi, Fujii Masao
Discussion: https://postgr.es/m/9a60178c-a853-1440-2cdc-c3af916cff59@amazon.com
Aside from being queriable via SHOW, this value is sent to the client
immediately at session startup, and again later on if the server gets
promoted to primary during the session. The immediate report will be
used in an upcoming patch to avoid an extra round trip when trying to
connect to a primary server.
Haribabu Kommi, Greg Nancarrow, Tom Lane; reviewed at various times
by Laurenz Albe, Takayuki Tsunakawa, Peter Smith.
Discussion: https://postgr.es/m/CAF3+xM+8-ztOkaV9gHiJ3wfgENTq97QcjXQt+rbFQ6F7oNzt9A@mail.gmail.com
- Misc grammar and punctuation fixes.
- Stylistic cleanup: use spaces between function arguments and JSON fields
in examples. For example "foo(a,b)" -> "foo(a, b)". Add semicolon after
last END in a few PL/pgSQL examples that were missing them.
- Make sentence that talked about "..." and ".." operators more clear,
by avoiding to end the sentence with "..". That makes it look the same
as "..."
- Fix syntax description for HAVING: HAVING conditions cannot be repeated
Patch by Justin Pryzby, per Yaroslav Schekin's report. Backpatch to all
supported versions, to the extent that the patch applies easily.
Discussion: https://www.postgresql.org/message-id/20201005191922.GE17626%40telsasoft.com
This clarifies some wording in the description of the options available
as replication solutions. While on it, this replaces some instances of
"master" with "primary", for consistency with recent changes like
9e101cf.
Author: Robert Treat
Reviewed-by: Magnus Hagander, Michael Paquier
Discussion: https://postgr.es/m/CAJSLCQ2TPaK_K8raofCamrqELCxY-H6mJrpDNRzc-LKpPY7c+g@mail.gmail.com
Previously the standby server didn't archive timeline history files
streamed from the primary even when archive_mode is set to "always",
while it archives the streamed WAL files. This could cause the PITR to
fail because there was no required timeline history file in the archive.
The cause of this issue was that walreceiver didn't mark those files as
ready for archiving.
This commit makes walreceiver mark those streamed timeline history
files as ready for archiving if archive_mode=always. Then the archiver
process archives the marked timeline history files.
Back-patch to all supported versions.
Reported-by: Grigory Smolkin
Author: Grigory Smolkin, Fujii Masao
Reviewed-by: David Zhang, Anastasia Lubennikova
Discussion: https://postgr.es/m/54b059d4-2b48-13a4-6f43-95a087c92367@postgrespro.ru
Fix one instance of a table cell overflow by adding a zero-width
space. The visual impact of this is minimal, but since this is
currently the only such case reported by FOP ("contents of ... exceed
the available area"), it seems worth getting rid of.
In "High Availability, Load Balancing, and Replication" chapter,
certain descriptions of Pgpool-II were not correct at this point. It
does not need conflict resolution. Also "Multiple-Server Parallel
Query Execution" is not supported anymore.
Discussion: https://postgr.es/m/20200726.230128.53842489850344110.t-ishii%40sraoss.co.jp
Author: Tatsuo Ishii
Reviewed-by: Bruce Momjian
Backpatch-through: 9.5
max_slot_wal_keep_size that was added in v13 and wal_keep_segments are
the GUC parameters to specify how much WAL files to retain for
the standby servers. While max_slot_wal_keep_size accepts the number of
bytes of WAL files, wal_keep_segments accepts the number of WAL files.
This difference of setting units between those similar parameters could
be confusing to users.
To alleviate this situation, this commit renames wal_keep_segments to
wal_keep_size, and make users specify the WAL size in it instead of
the number of WAL files.
There was also the idea to rename max_slot_wal_keep_size to
max_slot_wal_keep_segments, in the discussion. But we have been moving
away from measuring in segments, for example, checkpoint_segments was
replaced by max_wal_size. So we concluded to rename wal_keep_segments
to wal_keep_size.
Back-patch to v13 where max_slot_wal_keep_size was added.
Author: Fujii Masao
Reviewed-by: Álvaro Herrera, Kyotaro Horiguchi, David Steele
Discussion: https://postgr.es/m/574b4ea3-e0f9-b175-ead2-ebea7faea855@oss.nttdata.com
This commit updates the "Viewing Statistics" section more like
the existing catalogs chapter.
- Change its layout so that an introductory paragrap is put above
the table for each statistics view. Previously the explanations
were below the tables.
- Separate each view to different section and add index terms for them.
Author: Fujii Masao
Reviewed-by: Tom Lane
Discussion: https://postgr.es/m/6f8a482c-b3fa-4ed9-21c3-6d222a2cb87d@oss.nttdata.com
I abbreviated the heck out of the column headings, and made a few
small wording changes, to get it to build warning-free. I can't
say that the result is pretty, but it's probably better than
removing this table entirely.
As of this commit, we have zero "exceed the available area" warnings
in a US-letter PDF build, and one such warning (about an 863-millipoint
overrun) in an A4 build. I expect to get rid of that one by renaming
wait events, so I'm not doing anything about it at the formatting
level.
Discussion: https://postgr.es/m/6916.1589146280@sss.pgh.pa.us
The following docs are updated:
- High-availaility section
- pg_basebackup
- pg_receivewal
Per the principle of least privilege, we want to encourage users to
interact with those areas using roles that have replication rights, but
superusers were mentioned first.
Author: Daniel Gustafsson
Reviewed-by: Fujii Masao, Michael Paquier
Discussion: https://postgr.es/m/ECEBD212-7101-41EB-84F3-2F356E4B6401@yesql.se
Previously in the "Standby Server Operation" section, pg_ctl promote and
protmote_trigger_file were documented as a method to trigger standby
promotion, but pg_promote() function not.
This commit also adds parentheses into <function>pg_promote</function>
in some docs to make it clearer that a function is being referred to.
Author: Masahiro Ikeda
Reviewed-by: Michael Paquier, Laurenz Albe, Tom Lane, Fujii Masao
Discussion: https://postgr.es/m/de0068417a9f4046bac693cbcc00bdc9@oss.nttdata.com
Replication slots are useful to retain data that may be needed by a
replication system. But experience has shown that allowing them to
retain excessive data can lead to the primary failing because of running
out of space. This new feature allows the user to configure a maximum
amount of space to be reserved using the new option
max_slot_wal_keep_size. Slots that overrun that space are invalidated
at checkpoint time, enabling the storage to be released.
Author: Kyotaro HORIGUCHI <horiguchi.kyotaro@lab.ntt.co.jp>
Reviewed-by: Masahiko Sawada <sawada.mshk@gmail.com>
Reviewed-by: Jehan-Guillaume de Rorthais <jgdr@dalibo.com>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/20170228.122736.123383594.horiguchi.kyotaro@lab.ntt.co.jp
When certain parameters are changed on a physical replication primary,
this is communicated to standbys using the XLOG_PARAMETER_CHANGE WAL
record. The standby then checks whether its own settings are at least
as big as the ones on the primary. If not, the standby shuts down
with a fatal error.
The correspondence of settings between primary and standby is required
because those settings influence certain shared memory sizings that
are required for processing WAL records that the primary might send.
For example, if the primary sends a prepared transaction, the standby
must have had max_prepared_transaction set appropriately or it won't
be able to process those WAL records.
However, fatally shutting down the standby immediately upon receipt of
the parameter change record might be a bit of an overreaction. The
resources related to those settings are not required immediately at
that point, and might never be required if the activity on the primary
does not exhaust all those resources. If we just let the standby roll
on with recovery, it will eventually produce an appropriate error when
those resources are used.
So this patch relaxes this a bit. Upon receipt of
XLOG_PARAMETER_CHANGE, we still check the settings but only issue a
warning and set a global flag if there is a problem. Then when we
actually hit the resource issue and the flag was set, we issue another
warning message with relevant information. At that point we pause
recovery, so a hot standby remains usable. We also repeat the last
warning message once a minute so it is harder to miss or ignore.
Reviewed-by: Sergei Kornilov <sk@zsrv.org>
Reviewed-by: Masahiko Sawada <masahiko.sawada@2ndquadrant.com>
Reviewed-by: Kyotaro Horiguchi <horikyota.ntt@gmail.com>
Discussion: https://www.postgresql.org/message-id/flat/4ad69a4c-cc9b-0dfe-0352-8b1b0cd36c7b@2ndquadrant.com
The parameters primary_conninfo, primary_slot_name and
wal_receiver_create_temp_slot can now be changed with a simple "reload"
signal, no longer requiring a server restart. This is achieved by
signalling the walreceiver process to terminate and having it start
again with the new values.
Thanks to Andres Freund, Kyotaro Horiguchi, Fujii Masao for discussion.
Author: Sergei Kornilov <sk@zsrv.org>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Reviewed-by: Álvaro Herrera <alvherre@alvh.no-ip.org>
Discussion: https://postgr.es/m/19513901543181143@sas1-19a94364928d.qloud-c.yandex.net
Since its introduction, max_wal_senders is counted as part of
max_connections when it comes to define how many connection slots can be
used for replication connections with a WAL sender context. This can
lead to confusion for some users, as it could be possible to block a
base backup or replication from happening because other backend sessions
are already taken for other purposes by an application, and
superuser-only connection slots are not a correct solution to handle
that case.
This commit makes max_wal_senders independent of max_connections for its
handling of PGPROC entries in ProcGlobal, meaning that connection slots
for WAL senders are handled using their own free queue, like autovacuum
workers and bgworkers.
One compatibility issue that this change creates is that a standby now
requires to have a value of max_wal_senders at least equal to its
primary. So, if a standby created enforces the value of
max_wal_senders to be lower than that, then this could break failovers.
Normally this should not be an issue though, as any settings of a
standby are inherited from its primary as postgresql.conf gets normally
copied as part of a base backup, so parameters would be consistent.
Author: Alexander Kukushkin
Reviewed-by: Kyotaro Horiguchi, Petr Jelínek, Masahiko Sawada, Oleksii
Kliukin
Discussion: https://postgr.es/m/CAFh8B=nBzHQeYAu0b8fjK-AF1X4+_p6GRtwG+cCgs6Vci2uRuQ@mail.gmail.com
Since LISTEN is (still) disallowed, UNLISTEN must be a no-op in a
hot-standby session, and so there's no harm in allowing it. This
change allows client code to not worry about whether it's connected
to a primary or standby server when performing session-state-reset
type activities. (Note that DISCARD ALL, which includes UNLISTEN,
was already allowed, making it inconsistent to reject UNLISTEN.)
Per discussion, back-patch to all supported versions.
Shay Rojansky, reviewed by Mi Tar
Discussion: https://postgr.es/m/CADT4RqCf2gA_TJtPAjnGzkC3ZiexfBZiLmA-mV66e4UyuVv8bA@mail.gmail.com
recovery.conf settings are now set in postgresql.conf (or other GUC
sources). Currently, all the affected settings are PGC_POSTMASTER;
this could be refined in the future case by case.
Recovery is now initiated by a file recovery.signal. Standby mode is
initiated by a file standby.signal. The standby_mode setting is
gone. If a recovery.conf file is found, an error is issued.
The trigger_file setting has been renamed to promote_trigger_file as
part of the move.
The documentation chapter "Recovery Configuration" has been integrated
into "Server Configuration".
pg_basebackup -R now appends settings to postgresql.auto.conf and
creates a standby.signal file.
Author: Fujii Masao <masao.fujii@gmail.com>
Author: Simon Riggs <simon@2ndquadrant.com>
Author: Abhijit Menon-Sen <ams@2ndquadrant.com>
Author: Sergei Kornilov <sk@zsrv.org>
Discussion: https://www.postgresql.org/message-id/flat/607741529606767@web3g.yandex.ru/
This function is able to promote a standby with this new SQL-callable
function. Execution access can be granted to non-superusers so that
failover tools can observe the principle of least privilege.
Catalog version is bumped.
Author: Laurenz Albe
Reviewed-by: Michael Paquier, Masahiko Sawada
Discussion: https://postgr.es/m/6e7c79b3ec916cf49742fb8849ed17cd87aed620.camel@cybertec.at
Being able to use a value that can be changed on a connection basis is
useful with clusters distributed geographically, and makes failure
detection more flexible. A note is added in the documentation about the
use of "options" in primary_conninfo, which can be hard to grasp for
newcomers with the need of two single quotes when listing a set of
parameters.
Author: Tsunakawa Takayuki
Reviewed-by: Masahiko Sawada, Michael Paquier
Discussion: https://postgr.es/m/0A3221C70F24FB45833433255569204D1FAAD3AE@G01JPEXMBYT05
The example output of pg_replication_slot is wrong. Correct it and make
the output stable by explicitly listing columns to output.
Author: Kyotaro Horiguchi <horiguchi.kyotaro@lab.ntt.co.jp>
Reviewed-by: Michael Paquier <michael@paquier.xyz>
Discussion: https://postgr.es/m/20180731.190909.42582169.horiguchi.kyotaro@lab.ntt.co.jp
The backup history file has been no longer necessary for recovery
since the version 9.0. It's now basically just for informational purpose.
But previously the documentations still described that a recovery
requests the backup history file to proceed. The commit fixes this
documentation bug.
Back-patch to all supported versions.
Author: Yugo Nagata
Reviewed-by: Kyotaro Horiguchi
Discussion: https://postgr.es/m/20180626174752.0ce505e3.nagata@sraoss.co.jp
Since some preparation work had already been done, the only source
changes left were changing empty-element tags like <xref linkend="foo">
to <xref linkend="foo"/>, and changing the DOCTYPE.
The source files are still named *.sgml, but they are actually XML files
now. Renaming could be considered later.
In the build system, the intermediate step to convert from SGML to XML
is removed. Everything is build straight from the source files again.
The OpenSP (or the old SP) package is no longer needed.
The documentation toolchain instructions are updated and are much
simpler now.
Peter Eisentraut, Alexander Lakhin, Jürgen Purtz
Also make the link to pg_stat_replication more precise.
Author: Michael Paquier <michael.paquier@gmail.com>
Reviewed-by: Jeff Janes <jeff.janes@gmail.com>
Document the order of changing certain settings when using hot-standby
servers. This is just a logical consequence of what was already
documented, but it gives the users some more practical advice.
Author: Yorick Peterse <yorickpeterse@gmail.com>
Reviewed-by: Aleksander Alekseev <a.alekseev@postgrespro.ru>
Reviewed-by: Robert Haas <robertmhaas@gmail.com>
For DocBook XML compatibility, don't use SGML empty tags (</>) anymore,
replace by the full tag name. Add a warning option to catch future
occurrences.
Alexander Lakhin, Jürgen Purtz
Update the documentation a bit to include that logical replication as
well as other and third-party replication clients can participate in
synchronous replication.
Startup process is displayed in pg_stat_activity, noted by Yugo Nagata.
Transactions can be resolved at end of recovery.
Author: Yugo Nagata, with addition by me
Per discussion, "location" is a rather vague term that could refer to
multiple concepts. "LSN" is an unambiguous term for WAL locations and
should be preferred. Some function names, view column names, and function
output argument names used "lsn" already, but others used "location",
as well as yet other terms such as "wal_position". Since we've already
renamed a lot of things in this area from "xlog" to "wal" for v10,
we may as well incur a bit more compatibility pain and make these names
all consistent.
David Rowley, minor additional docs hacking by me
Discussion: https://postgr.es/m/CAKJS1f8O0njDKe8ePFQ-LK5-EjwThsDws6ohJ-+c6nWK+oUxtg@mail.gmail.com
Thomas Munro
Peter Eisentraut
Fujii Masao
Tom Lane
Heikki Linnakangas
Michael Paquier
Bruce Momjian
Tatsuo Ishii
Andres Freund
Alvaro Herrera
Peter Eisentraut
Simon Riggs