Commit f82ec32ac3 renamed the pg_xlog
directory to pg_wal. To make things consistent, and because "xlog" is
terrible terminology for either "transaction log" or "write-ahead log"
rename all SQL-callable functions that contain "xlog" in the name to
instead contain "wal". (Note that this may pose an upgrade hazard for
some users.)
Similarly, rename the xlog_position argument of the functions that
create slots to be called wal_position.
Discussion: https://www.postgresql.org/message-id/CA+Tgmob=YmA=H3DbW1YuOXnFVgBheRmyDkWcD9M8f=5bGWYEoQ@mail.gmail.com
Hot_standby_feedback could be reset by reload and worked correctly, but if
the server was restarted rather than reloaded the xmin was not reset.
Force reset always if hot_standby_feedback is enabled at startup.
Ants Aasma, Craig Ringer
Reported-by: Ants Aasma
This changes the default values of the following parameters:
wal_level = replica
max_wal_senders = 10
max_replication_slots = 10
in order to make it possible to make a backup and set up simple
replication on the default settings, without requiring a system restart.
Discussion: https://postgr.es/m/CABUevEy4PR_EAvZEzsbF5s+V0eEvw7shJ2t-AUwbHOjT+yRb3A@mail.gmail.com
Reviewed by Peter Eisentraut. Benchmark help from Tomas Vondra.
Add methods to the core test framework PostgresNode.pm to allow us to
test that standby nodes have caught up with the master, as well as
basic LSN handling. Used in tests recovery/t/001_stream_rep.pl and
recovery/t/004_timeline_switch.pl
Craig Ringer, reviewed by Aleksander Alekseev and Simon Riggs
This feature is also known as "quorum commit" especially in discussion
on pgsql-hackers.
This commit adds the following new syntaxes into synchronous_standby_names
GUC. By using FIRST and ANY keywords, users can specify the method to
choose synchronous standbys from the listed servers.
FIRST num_sync (standby_name [, ...])
ANY num_sync (standby_name [, ...])
The keyword FIRST specifies a priority-based synchronous replication
which was available also in 9.6 or before. This method makes transaction
commits wait until their WAL records are replicated to num_sync
synchronous standbys chosen based on their priorities.
The keyword ANY specifies a quorum-based synchronous replication
and makes transaction commits wait until their WAL records are
replicated to *at least* num_sync listed standbys. In this method,
the values of sync_state.pg_stat_replication for the listed standbys
are reported as "quorum". The priority is still assigned to each standby,
but not used in this method.
The existing syntaxes having neither FIRST nor ANY keyword are still
supported. They are the same as new syntax with FIRST keyword, i.e.,
a priorirty-based synchronous replication.
Author: Masahiko Sawada
Reviewed-By: Michael Paquier, Amit Kapila and me
Discussion: <CAD21AoAACi9NeC_ecm+Vahm+MMA6nYh=Kqs3KB3np+MBOS_gZg@mail.gmail.com>
Many thanks to the various individuals who were involved in
discussing and developing this feature.
If a restartpoint flushed no dirty buffers, it could fail to update
the minimum recovery point, leading to a minimum recovery point prior
to the starting REDO location. perform_base_backup() would interpret
that as meaning that no WAL files at all needed to be included in the
backup, failing an internal sanity check. To fix, have restartpoints
always update the minimum recovery point to just after the checkpoint
record itself, so that the file (or files) containing the checkpoint
record will always be included in the backup.
Code by Amit Kapila, per a design suggestion by me, with some
additional work on the code comment by me. Test case by Michael
Paquier. Report by Kyotaro Horiguchi.
Switch TAP tests to use the new wait mode of pg_ctl promote. This
allows avoiding extra logic with poll_query_until() to be sure that a
promoted standby is ready for read-write queries.
From: Michael Paquier <michael.paquier@gmail.com>
When a relation is truncated, it is important that the FSM is truncated as
well. Otherwise, after recovery, the FSM can return a page that has been
truncated away, leading to errors like:
ERROR: could not read block 28991 in file "base/16390/572026": read only 0
of 8192 bytes
We were using MarkBufferDirtyHint() to dirty the buffer holding the last
remaining page of the FSM, but during recovery, that might in fact not
dirty the page, and the FSM update might be lost.
To fix, use the stronger MarkBufferDirty() function. MarkBufferDirty()
requires us to do WAL-logging ourselves, to protect from a torn page, if
checksumming is enabled.
Also fix an oversight in visibilitymap_truncate: it also needs to WAL-log
when checksumming is enabled.
Analysis by Pavan Deolasee.
Discussion: <CABOikdNr5vKucqyZH9s1Mh0XebLs_jRhKv6eJfNnD2wxTn=_9A@mail.gmail.com>
When pg_logical_slot_get_changes(...) sets confirmed_flush_lsn to the point at
which replay stopped, it doesn't dirty the replication slot. So if the replay
didn't cause restart_lsn or catalog_xmin to change as well, this change will
not get written out to disk. Even on a clean shutdown.
If Pg crashes or restarts, a subsequent pg_logical_slot_get_changes(...) call
will see the same changes already replayed since it uses the slot's
confirmed_flush_lsn as the start point for fetching changes. The caller can't
specify a start LSN when using the SQL interface.
Mark the slot as dirty after reading changes using the SQL interface so that
users won't see repeated changes after a clean shutdown. Repeated changes still
occur when using the walsender interface or after an unclean shutdown.
Craig Ringer
In test 001_stream_rep we're using pg_stat_replication.write_location to
determine catch-up status, but we care about xlog having been applied
not just received, so change that to apply_location.
In test 003_recovery_targets, we query the database for a recovery
target specification and later for the xlog position supposedly
corresponding to that recovery specification. If for whatever reason
more WAL is written between the two queries, the recovery specification
is earlier than the xlog position used by the query in the test harness,
so we wait forever, leading to test failures. Deal with this by using a
single query to extract both items. In 2a0f89cd71 we tried to deal
with it by giving them more tests to run, but in hindsight that was
obviously doomed to failure (no revert of that, though).
Per hamster buildfarm failures.
Author: Michaël Paquier
This reverts commits f07d18b6e9, 82c83b3372, 3a3b309041, and
24c5f1a103.
This feature has shown enough immaturity that it was deemed better to
rip it out before rushing some more fixes at the last minute. There are
discussions on larger changes in this area for the next release.
The regression test checks whether the output of pg_stat_replication is
expected or not after changing synchronous_standby_names and reloading
the configuration file. Regarding this test logic, previously there was
a timing issue which made the test result unstable. That is,
pg_stat_replication could return unexpected result during small window
after the configuration file was reloaded before new setting value
took effect, and which made the test fail.
This commit changes the test logic so that it uses a loop with a timeout
to give some room for the test to pass. Now the test fails only when
pg_stat_replication keeps returning unexpected result for 30 seconds.
Michael Paquier
In the test_slot_timelines test module, we were abusing passing NULL
values which was received as zeroes in x86, but this breaks in ARM
(buildfarm member hamster) by crashing instead. Fix the breakage by
marking these functions as STRICT; the InvalidXid value that was
previously implicit in NULL values (on x86 at least) can now be passed
as 0. Failing to follow the fmgr protocol to check for NULLs beforehand
was causing ARM to fail, as evidenced by segmentation faults in
buildfarm member hamster.
In order to use the new functionality in the test script, use COALESCE
in the right spot to avoid forwarding NULL values.
This was diagnosed from the hamster crash by Craig Ringer, who also
proposed a different patch (checking for NULL values explicitely in the
C function code, and keeping the non-strictness in the C functions).
I decided to go with this approach instead.
Previously this test was relying too much on WAL replay to occur in the
exact configured interval, which was unreliable on slow or overly busy
servers. Use a custom loop instead of poll_query_until, which is
hopefully more reliable.
Per continued failures on buildfarm member hamster (which is probably
the only one running this test suite)
Author: Michaël Paquier
When decoding from a logical slot, it's necessary for xlog reading to be
able to read xlog from historical (i.e. not current) timelines;
otherwise, decoding fails after failover, because the archives are in
the historical timeline. This is required to make "failover logical
slots" possible; it currently has no other use, although theoretically
it could be used by an extension that creates a slot on a standby and
continues to replay from the slot when the standby is promoted.
This commit includes a module in src/test/modules with functions to
manipulate the slots (which is not otherwise possible in SQL code) in
order to enable testing, and a new test in src/test/recovery to ensure
that the behavior is as expected.
Author: Craig Ringer
Reviewed-By: Oleksii Kliukin, Andres Freund, Petr Jelínek
This makes the psql() method much more capable: it captures both stdout
and stderr; it now returns the psql exit code rather than stdout; a
timeout can now be specified, as can ON_ERROR_STOP behavior; it gained a
new "on_error_die" (defaulting to off) parameter to raise an exception
if there's any problem. Finally, additional parameters to psql can be
passed if there's need for further tweaking.
For convenience, a new safe_psql() method retains much of the old
behavior of psql(), except that it uses on_error_die on, so that
problems like syntax errors in SQL commands can be detected more easily.
Many existing TAP test files now use safe_psql, which is what is really
wanted. A couple of ->psql() calls are now added in the commit_ts
tests, which verify that the right thing is happening on certain errors.
Some ->command_fails() calls in recovery tests that were verifying that
psql failed also became ->psql() calls now.
Author: Craig Ringer. Some tweaks by Álvaro Herrera
Reviewed-By: Michaël Paquier
One test was relying on method remove_tree that isn't implemented in the
oldest Perl we support; fix it by using the older rmtree instead.
Another test had a typo in a SQL command, which isn't noticed because
the PostgresNode->psql() method doesn't check that queries return
correctly. That's undesirable and will also be fixed later on, but for
now let's make the test actually work.
Author: Craig Ringer
I applied the previous-to-last revision of Michaël's submitted patch
instead of the last; these two tweaks pointed out by Craig were left out
of the previous commit by accident.
Robert Haas
Simon Riggs
Magnus Hagander
Bruce Momjian
Fujii Masao
Peter Eisentraut
Heikki Linnakangas
Tom Lane
Alvaro Herrera
Noah Misch