Horton

Re: Minimal logical decoding on standbys

Craig Ringer <craig@2ndquadrant.com>

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From: Craig Ringer <craig@2ndquadrant.com>
To: Robert Haas <robertmhaas@gmail.com>
Cc: Amit Khandekar <amitdkhan.pg@gmail.com>, Alvaro Herrera <alvherre@2ndquadrant.com>, Andres Freund <andres@anarazel.de>, tushar <tushar.ahuja@enterprisedb.com>, Petr Jelinek <petr.jelinek@2ndquadrant.com>, Petr Jelinek <petr@2ndquadrant.com>, pgsql-hackers <pgsql-hackers@postgresql.org>, Shaun Thomas <shaun.thomas@2ndquadrant.com>
Date: 2019-10-10T00:19:28Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Reduce the log level in 035_standby_logical_decoding.pl.

  2. 035_standby_logical_decoding: Add missing waits for replication

  3. For cascading replication, wake physical and logical walsenders separately

  4. Handle logical slot conflicts on standby

  5. Support invalidating replication slots due to horizon and wal_level

  6. Prevent use of invalidated logical slot in CreateDecodingContext()

  7. Replace replication slot's invalidated_at LSN with an enum

  8. Pass down table relation into more index relation functions

  9. Assert only valid flag bits are passed to visibilitymap_set()

  10. Remove unused _bt_delitems_delete() argument.

  11. Add xl_btree_delete optimization.

On Tue, 1 Oct 2019 at 02:08, Robert Haas <robertmhaas@gmail.com> wrote:

>
> Why does create_logical_slot_on_standby include sleep(1)?


Yeah, we really need to avoid sleeps in regression tests.

If you need to wait, use a DO block that polls the required condition, and
wrap the sleep in that with a much longer total timeout. In BDR and
pglogical's pg_regress tests I've started to use a shared prelude that sets
a bunch of psql variables that I use as helpers for this sort of thing, so
I can just write :wait_slot_ready instead of repeating the same SQL command
a pile of times across the tests.

That reminds me: I'm trying to find the time to write a couple of patches
to pg_regress to help make life easier too:

- Prelude and postscript .psql files that run before/after every test step
to set variables, do cleanup etc

- Test header comment that can be read by pg_regress to set a per-test
timeout

- Allow pg_regress to time out individual tests and continue with the next
test

- Test result postprocessing by script, where pg_regress writes the raw
test results then postprocesses it with a script before diffing the
postprocessed output. This would allow us to have things like /*
BEGIN_TESTIGNORE */ ... /* END_TESTIGNORE */ blocks for diagnostic output
that we want available but don't want to be part of actual test output. Or
filter out NOTICEs that vary in output. That sort of thing.

-- 
 Craig Ringer                   http://www.2ndQuadrant.com/
 2ndQuadrant - PostgreSQL Solutions for the Enterprise