This patch adds a new SUBSCRIPTION parameter "origin". It specifies
whether the subscription will request the publisher to only send changes
that don't have an origin or send changes regardless of origin. Setting it
to "none" means that the subscription will request the publisher to only
send changes that have no origin associated. Setting it to "any" means
that the publisher sends changes regardless of their origin. The default
is "any".
Usage:
CREATE SUBSCRIPTION sub1 CONNECTION 'dbname=postgres port=9999'
PUBLICATION pub1 WITH (origin = none);
This can be used to avoid loops (infinite replication of the same data)
among replication nodes.
This feature allows filtering only the replication data originating from
WAL but for initial sync (initial copy of table data) we don't have such a
facility as we can only distinguish the data based on origin from WAL. As
a follow-up patch, we are planning to forbid the initial sync if the
origin is specified as none and we notice that the publication tables were
also replicated from other publishers to avoid duplicate data or loops.
We forbid to allow creating origin with names 'none' and 'any' to avoid
confusion with the same name options.
Author: Vignesh C, Amit Kapila
Reviewed-By: Peter Smith, Amit Kapila, Dilip Kumar, Shi yu, Ashutosh Bapat, Hayato Kuroda
Discussion: https://postgr.es/m/CALDaNm0gwjY_4HFxvvty01BOT01q_fJLKQ3pWP9=9orqubhjcQ@mail.gmail.com
Some of the test_decoding regression tests are unstable due to modifying
a sequence. The first increment of a sequence after a checkpoint is
always logged (and thus decoded), which makes the output unpredictable.
The runs are usually much shorter than a checkpoint internal, so these
failures are rare, but we've seen a couple of them on animals that are
either slow or are running with valgrind/clobber cache/...
Fixed by skipping sequence decoding in most tests, with the exception of
the test aimed at testing decoding of sequences.
Reported-by: Amita Kapila
Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com
Commit 0da92dc530 improved the logical decoding infrastructure to handle
sequences, and did various changes to related parts (WAL logging etc.).
But it did not include any implementation of the new callbacks added to
OutputPluginCallbacks.
This extends test_decoding with two callbacks to decode sequences. The
decoding of sequences may be disabled using 'include-sequences', a new
option of the output plugin.
Author: Tomas Vondra, Cary Huang
Reviewed-by: Peter Eisentraut, Hannu Krosing, Andres Freund
Discussion: https://postgr.es/m/d045f3c2-6cfb-06d3-5540-e63c320df8bc@enterprisedb.com
Discussion: https://postgr.es/m/1710ed7e13b.cd7177461430746.3372264562543607781@highgo.ca
When using replication origins, pg_replication_origin_xact_setup() is an
optional choice to be able to set a LSN and a timestamp to mark the
origin, which would be additionally added to WAL for transaction commits
or aborts (including 2PC transactions). An assertion in the code path
of PREPARE TRANSACTION assumed that this data should always be set, so
it would trigger when using replication origins without setting up an
origin LSN. Some tests are added to cover more this kind of scenario.
Oversight in commit 1eb6d65.
Per discussion with Amit Kapila and Masahiko Sawada.
Discussion: https://postgr.es/m/YbbBfNSvMm5nIINV@paquier.xyz
Backpatch-through: 11
This patch removes the hardcoded check for superuser privileges when
executing replication origin functions. Instead, execution is revoked
from public, meaning that those functions can be executed by a superuser
and that access to them can be granted.
Author: Martín Marqués
Reviewed-by: Kyotaro Horiguchi, Michael Paquier, Masahiko Sawada
Discussion: https:/postgr.es/m/CAPdiE1xJMZOKQL3dgHMUrPqysZkgwzSMXETfKkHYnBAB7-0VRQ@mail.gmail.com
In commit 18555b132 we tentatively established a rule that regression
tests should use names containing "regression" for databases, and names
starting with "regress_" for all other globally-visible object names, so
as to circumscribe the side-effects that "make installcheck" could have on
an existing installation. However, no enforcement mechanism was created,
so it's unsurprising that some new violations have crept in since then.
In fact, a whole new *category* of violations has crept in, to wit we now
also have globally-visible subscription and replication origin names, and
"make installcheck" could very easily clobber user-created objects of
those types. So it's past time to do something about this.
This commit sanitizes the tests enough that they will pass (i.e. not
generate any visible warnings) with the enforcement mechanism I'll add
in the next commit. There are some TAP tests that still trigger the
warnings, but the warnings do not cause test failure. Since these tests
do not actually run against a pre-existing installation, there's no need
to worry whether they could conflict with user-created objects.
The problem with rolenames.sql testing special role names like "user"
is still there, and is dealt with only very cosmetically in this patch
(by hiding the warnings :-(). What we actually need to do to be safe is
to take that test script out of "make installcheck" altogether, but that
seems like material for a separate patch.
Discussion: https://postgr.es/m/16638.1468620817@sss.pgh.pa.us
Logical messages, added in 3fe3511d05, during decoding failed to filter
messages emitted in other databases and messages emitted "under" a
replication origin the output plugin isn't interested in.
Add tests to verify that both types of filtering actually work. While
touching message.sql remove hunk obsoleted by d25379e.
Bump XLOG_PAGE_MAGIC because xl_logical_message changed and because
3fe3511d05 had omitted doing so. 3fe3511d05 additionally didn't bump
catversion, but 7a542700d has done so since.
Author: Petr Jelinek
Reported-By: Andres Freund
Discussion: 20160406142513.wotqy3ba3kanr423@alap3.anarazel.de
When implementing a replication solution ontop of logical decoding, two
related problems exist:
* How to safely keep track of replication progress
* How to change replication behavior, based on the origin of a row;
e.g. to avoid loops in bi-directional replication setups
The solution to these problems, as implemented here, consist out of
three parts:
1) 'replication origins', which identify nodes in a replication setup.
2) 'replication progress tracking', which remembers, for each
replication origin, how far replay has progressed in a efficient and
crash safe manner.
3) The ability to filter out changes performed on the behest of a
replication origin during logical decoding; this allows complex
replication topologies. E.g. by filtering all replayed changes out.
Most of this could also be implemented in "userspace", e.g. by inserting
additional rows contain origin information, but that ends up being much
less efficient and more complicated. We don't want to require various
replication solutions to reimplement logic for this independently. The
infrastructure is intended to be generic enough to be reusable.
This infrastructure also replaces the 'nodeid' infrastructure of commit
timestamps. It is intended to provide all the former capabilities,
except that there's only 2^16 different origins; but now they integrate
with logical decoding. Additionally more functionality is accessible via
SQL. Since the commit timestamp infrastructure has also been introduced
in 9.5 (commit 73c986add) changing the API is not a problem.
For now the number of origins for which the replication progress can be
tracked simultaneously is determined by the max_replication_slots
GUC. That GUC is not a perfect match to configure this, but there
doesn't seem to be sufficient reason to introduce a separate new one.
Bumps both catversion and wal page magic.
Author: Andres Freund, with contributions from Petr Jelinek and Craig Ringer
Reviewed-By: Heikki Linnakangas, Petr Jelinek, Robert Haas, Steve Singer
Discussion: 20150216002155.GI15326@awork2.anarazel.de,
20140923182422.GA15776@alap3.anarazel.de,
20131114172632.GE7522@alap2.anarazel.de
Amit Kapila
Tomas Vondra
Michael Paquier
Tom Lane
Robert Haas
Andres Freund