Horton

RE: speed up a logical replica setup

Hayato Kuroda (Fujitsu) <kuroda.hayato@fujitsu.com>

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From: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
To: 'Euler Taveira' <euler@eulerto.com>
Cc: "pgsql-hackers@lists.postgresql.org" <pgsql-hackers@lists.postgresql.org>, Amit Kapila <amit.kapila16@gmail.com>, Andres Freund <andres@anarazel.de>, Ashutosh Bapat <ashutosh.bapat.oss@gmail.com>, Michael Paquier <michael@paquier.xyz>, Peter Eisentraut <peter@eisentraut.org>
Date: 2024-01-05T10:06:11Z
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

Dear Euler,

I love your proposal, so I want to join the review. Here are my first comments.

01. 
Should we restrict that `--subscriber-conninfo` must not have hostname or IP?
We want users to execute pg_subscriber on the target, right?

02.
When the application was executed, many outputs filled my screen. Some of them
were by pg_subscriber, and others were server log. Can we record them into
separated file? I imagined like pg_upgrade.

03.
A replication command is used when replication slots are created. Is there a
reason to use it? I think we do not have to use logical replication walsender mode,
we can use an SQL function instead. pg_create_logical_replication_slot() also outputs
LSN, isn't it sufficient?

04.
As you know, there are several options for publications/subscriptions/replication
slots. Do you have a good way to specify them in your mind? 

05.
I found that the connection string for each subscriptions have a setting
"fallback_application_name=pg_subscriber". Can we remove it?

```
postgres=# SELECT subconninfo FROM pg_subscription;
                                   subconninfo                                   
---------------------------------------------------------------------------------
 user=postgres port=5431 fallback_application_name=pg_subscriber dbname=postgres
(1 row)
```

Best Regards,
Hayato Kuroda
FUJITSU LIMITED