Re: O(n) tasks cause lengthy startups and checkpoints

From: Nathan Bossart <nathandbossart(at)gmail(dot)com>
To: Andres Freund <andres(at)anarazel(dot)de>
Cc: Simon Riggs <simon(dot)riggs(at)enterprisedb(dot)com>, Robert Haas <robertmhaas(at)gmail(dot)com>, "Bossart, Nathan" <bossartn(at)amazon(dot)com>, Bharath Rupireddy <bharath(dot)rupireddyforpostgres(at)gmail(dot)com>, Maxim Orlov <orlovmg(at)gmail(dot)com>, Amul Sul <sulamul(at)gmail(dot)com>, Bruce Momjian <bruce(at)momjian(dot)us>, "pgsql-hackers(at)postgresql(dot)org" <pgsql-hackers(at)postgresql(dot)org>
Subject: Re: O(n) tasks cause lengthy startups and checkpoints
Date: 2022-08-11 23:09:21
Message-ID: 20220811230921.GA1707962@nathanxps13
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On Wed, Jul 06, 2022 at 09:51:10AM -0700, Nathan Bossart wrote:
> Here's a new revision where I've attempted to address all the feedback I've
> received thus far. Notably, the custodian now uses a queue for registering
> tasks and determining which tasks to execute. Other changes include
> splitting the temporary file functions apart to avoid consecutive boolean
> flags, using a timestamp instead of an integer for the staging name for
> temporary directories, moving temporary directories to a dedicated
> directory so that the custodian doesn't need to scan relation files,
> ERROR-ing when something goes wrong when cleaning up temporary files,
> executing requested tasks immediately in single-user mode, and more.

Here is a rebased patch set for cfbot. There are no other differences
between v7 and v8.

Nathan Bossart
Amazon Web Services:

Attachment Content-Type Size
v8-0001-Introduce-custodian.patch text/x-diff 24.1 KB
v8-0002-Also-remove-pgsql_tmp-directories-during-startup.patch text/x-diff 4.8 KB
v8-0003-Split-pgsql_tmp-cleanup-into-two-stages.patch text/x-diff 14.2 KB
v8-0004-Move-pgsql_tmp-file-removal-to-custodian-process.patch text/x-diff 5.5 KB
v8-0005-Move-removal-of-old-serialized-snapshots-to-custo.patch text/x-diff 4.6 KB
v8-0006-Move-removal-of-old-logical-rewrite-mapping-files.patch text/x-diff 9.2 KB

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