Horton

Re: [PoC] pg_upgrade: allow to upgrade publisher node

Dilip Kumar <dilipbalaut@gmail.com>

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From: Dilip Kumar <dilipbalaut@gmail.com>
To: "Hayato Kuroda (Fujitsu)" <kuroda.hayato@fujitsu.com>
Cc: Amit Kapila <amit.kapila16@gmail.com>, Peter Smith <smithpb2250@gmail.com>, PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>, Bruce Momjian <bruce@momjian.us>, Julien Rouhaud <rjuju123@gmail.com>, vignesh C <vignesh21@gmail.com>, Masahiko Sawada <sawada.mshk@gmail.com>, "Zhijie Hou (Fujitsu)" <houzj.fnst@fujitsu.com>
Date: 2023-08-31T13:22:59Z
Lists: pgsql-hackers 
On Tue, Aug 29, 2023 at 5:28 PM Hayato Kuroda (Fujitsu)
<kuroda.hayato@fujitsu.com> wrote:

Some comments in 0002

1.
+ res = executeQueryOrDie(conn, "SELECT slot_name "
+ "FROM pg_catalog.pg_replication_slots "
+ "WHERE slot_type = 'logical' AND "
+ "temporary IS FALSE;");

What is the reason we are ignoring temporary slots here?  I think we
better explain in the comments.

2.
+ res = executeQueryOrDie(conn, "SELECT slot_name "
+ "FROM pg_catalog.pg_replication_slots "
+ "WHERE slot_type = 'logical' AND "
+ "temporary IS FALSE;");
+
+ if (PQntuples(res))
+ pg_fatal("New cluster must not have logical replication slots but
found \"%s\"",
+ PQgetvalue(res, 0, 0));

It looks a bit odd to me that first it is fetching all the logical
slots from the new cluster and then printing the name of one of the
slots.  If it is printing the name of the slots then shouldn't it be
printing all the slots' names or it should just say that there
existing slots on the new cluster without giving any names?  And if we
are planning for option 2 i.e. not printing the name then better to
put LIMIT 1 at the end of the query.

-- 
Regards,
Dilip Kumar
EnterpriseDB: http://www.enterprisedb.com

Commits

  1. Fix issues in binary_upgrade_logical_slot_has_caught_up().

  2. Fix a random failure in 003_logical_slots.pl.

  3. Fix a test in 003_logical_slots.

  4. Fix uninitialized slot array access during the upgrade.

  5. Fix the test 003_logical_slots.

  6. Commit b195e6d482 forgot to update meson.build.

  7. Use shorter file names in the upgrade logical slots test.

  8. Migrate logical slots to the new node during an upgrade.

  9. Flush logical slots to disk during a shutdown checkpoint if required.

  10. Prevent possibility of panics during shutdown checkpoint.