Horton

Re: speed up a logical replica setup

Shlok Kyal <shlok.kyal.oss@gmail.com>

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From: Shlok Kyal <shlok.kyal.oss@gmail.com>
To: Amit Kapila <amit.kapila16@gmail.com>
Cc: Euler Taveira <euler@eulerto.com>, vignesh C <vignesh21@gmail.com>, Michael Paquier <michael@paquier.xyz>, Peter Eisentraut <peter@eisentraut.org>, pgsql-hackers@lists.postgresql.org, Andres Freund <andres@anarazel.de>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>
Date: 2024-01-05T06:49:14Z
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. pg_createsubscriber: Remove obsolete comment

  2. pg_createsubscriber: Fix an unpredictable recovery wait time.

  3. Fix unstable test in 040_pg_createsubscriber.

  4. Fix the testcase introduced in commit 81d20fbf7a.

  5. Further weaken new pg_createsubscriber test on Windows.

  6. Temporarily(?) weaken new pg_createsubscriber test on Windows.

  7. Make pg_createsubscriber warn if publisher has two-phase commit enabled.

  8. Make pg_createsubscriber more wary about quoting connection parameters.

  9. pg_createsubscriber: Remove failover replication slots on subscriber

  10. pg_createsubscriber: Remove replication slot check on primary

  11. pg_createsubscriber: Only --recovery-timeout controls the end of recovery process

  12. pg_createsubscriber: creates a new logical replica from a standby server

  13. Add some const decorations

  14. Add option force_initdb to PostgreSQL::Test::Cluster:init()

  15. Remove MSVC scripts

On Thu, 4 Jan 2024 at 16:46, Amit Kapila <amit.kapila16@gmail.com> wrote:
>
> On Thu, Jan 4, 2024 at 12:22 PM Shlok Kyal <shlok.kyal.oss@gmail.com> wrote:
> >
> > Hi,
> > I was testing the patch with following test cases:
> >
> > Test 1 :
> > - Create a 'primary' node
> > - Setup physical replica using pg_basebackup  "./pg_basebackup –h
> > localhost –X stream –v –R –W –D ../standby "
> > - Insert data before and after pg_basebackup
> > - Run pg_subscriber and then insert some data to check logical
> > replication "./pg_subscriber –D ../standby -S “host=localhost
> > port=9000 dbname=postgres” -P “host=localhost port=9000
> > dbname=postgres” -d postgres"
> > - Also check pg_publication, pg_subscriber and pg_replication_slots tables.
> >
> > Observation:
> > Data is not lost. Replication is happening correctly. Pg_subscriber is
> > working as expected.
> >
> > Test 2:
> > - Create a 'primary' node
> > - Use normal pg_basebackup but don’t set up Physical replication
> > "./pg_basebackup –h localhost –v –W –D ../standby"
> > - Insert data before and after pg_basebackup
> > - Run pg_subscriber
> >
> > Observation:
> > Pg_subscriber command is not completing and is stuck with following
> > log repeating:
> > LOG: waiting for WAL to become available at 0/3000168
> > LOG: invalid record length at 0/3000150: expected at least 24, got 0
> >
>
> I think probably the required WAL is not copied. Can you use the -X
> option to stream WAL as well and then test? But I feel in this case
> also, we should wait for some threshold time and then exit with
> failure, removing new objects created, if any.

I have tested with -X stream option in pg_basebackup as well. In this
case also the pg_subscriber command is getting stuck.
logs:
2024-01-05 11:49:34.436 IST [61948] LOG:  invalid resource manager ID
102 at 0/3000118
2024-01-05 11:49:34.436 IST [61948] LOG:  waiting for WAL to become
available at 0/3000130

>
> > Test 3:
> > - Create a 'primary' node
> > - Use normal pg_basebackup but don’t set up Physical replication
> > "./pg_basebackup –h localhost –v –W –D ../standby"
> > -Insert data before pg_basebackup but not after pg_basebackup
> > -Run pg_subscriber
> >
> > Observation:
> > Pg_subscriber command is not completing and is stuck with following
> > log repeating:
> > LOG: waiting for WAL to become available at 0/3000168
> > LOG: invalid record length at 0/3000150: expected at least 24, got 0
> >
>
> This is similar to the previous test and you can try the same option
> here as well.
For this test as well tried with -X stream option  in pg_basebackup.
It is getting stuck here as well with similar log.

Will investigate the issue further.


Thanks and regards
Shlok Kyal