Somebody added pg_replication_origin, pg_replication_origin_status and
pg_replication_slots to catalogs.sgml without a whole lot of concern for
either alphabetical order or the difference between a table and a view.
Clean up the mess.
Back-patch to 9.5, not so much because this is critical as because if
I don't it will result in a cross-branch divergence in release-9.5.sgml,
which would be a maintenance hazard.
API and mechanism to allow generic messages to be inserted into WAL that are
intended to be read by logical decoding plugins. This commit adds an optional
new callback to the logical decoding API.
Messages are either text or bytea. Messages can be transactional, or not, and
are identified by a prefix to allow multiple concurrent decoding plugins.
(Not to be confused with Generic WAL records, which are intended to allow crash
recovery of extensible objects.)
Author: Petr Jelinek and Andres Freund
Reviewers: Artur Zakirov, Tomas Vondra, Simon Riggs
Discussion: 5685F999.6010202@2ndquadrant.com
There's no reason not to expose both restart_lsn and confirmed_flush
since they have rather distinct meanings. The former is the oldest WAL
still required and valid for both physical and logical slots, whereas
the latter is the location up to which a logical slot's consumer has
confirmed receiving data. Most of the time a slot will require older
WAL (i.e. restart_lsn) than the confirmed
position (i.e. confirmed_flush_lsn).
Author: Marko Tiikkaja, editorialized by me
Discussion: 559D110B.1020109@joh.to
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
Right now it is visible whether a replication slot is active in any
session, but not in which. Adding the active_in column, containing the
pid of the backend having acquired the slot, makes it much easier to
associate pg_replication_slots entries with the corresponding
pg_stat_replication/pg_stat_activity row.
This should have been done from the start, but I (Andres) dropped the
ball there somehow.
Author: Craig Ringer, revised by me Discussion:
CAMsr+YFKgZca5_7_ouaMWxA5PneJC9LNViPzpDHusaPhU9pA7g@mail.gmail.com
A future patch (9.5 only) adds slot management to pg_receivexlog. The
verbs create/drop don't seem descriptive enough there. It seems better
to rename pg_recvlogical's commands now, in beta, than live with the
inconsistency forever.
The old form (e.g. --drop) will still be accepted by virtue of most
getopt_long() options accepting abbreviations for long commands.
Backpatch to 9.4 where pg_recvlogical was introduced.
Author: Michael Paquier and Andres Freund
Discussion: CAB7nPqQtt79U6FmhwvgqJmNyWcVCbbV-nS72j_jyPEopERg9rg@mail.gmail.com
Previously the duplicated paragraphs were used next to each other
in the document to demonstrate that the changes in the stream
were not consumed by pg_logical_slot_peek_changes function.
But some users misunderstood that the duplication of the same
paragraph was just typo. So this commit rewords the sentence in
the latter paragraph for less confusing.
Christoph Moench-Tegeder
Previously there's been a mix between 'slotname' and 'slot_name'. It's
not nice to be unneccessarily inconsistent in a new feature. As a post
beta1 initdb now is required in the wake of eeca4cd35e, fix the
inconsistencies.
Most the changes won't affect usage of replication slots because the
majority of changes is around function parameter names. The prominent
exception to that is that the recovery.conf parameter
'primary_slotname' is now named 'primary_slot_name'.
The main problem is that DocBook SGML allows indexterm elements just
about everywhere, but DocBook XML is stricter. For example, this common
pattern
<varlistentry>
<indexterm>...</indexterm>
<term>...</term>
...
</varlistentry>
needs to be changed to something like
<varlistentry>
<term>...<indexterm>...</indexterm></term>
...
</varlistentry>
See also bb4eefe7bf.
There is currently nothing in the build system that enforces that things
stay valid, because that requires additional tools and will receive
separate consideration.
Simon Riggs
Alvaro Herrera
Tom Lane
Peter Eisentraut
Fujii Masao
Andres Freund
Magnus Hagander
Heikki Linnakangas
Robert Haas