user/dev discussion of public-inbox itself
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From: Eric Wong <e@80x24.org>
To: meta@public-inbox.org
Cc: Ricardo Ribalda <ribalda@chromium.org>
Subject: [PATCH] lei q|up: limit default write --jobs for IMAP(S)
Date: Mon, 14 Nov 2022 08:07:02 +0000	[thread overview]
Message-ID: <20221114080702.M933003@dcvr> (raw)
In-Reply-To: <20220910201958.GA12212@dcvr>

Eric Wong <e@80x24.org> wrote:
> Thanks for confirming things work as intended.  I think the
> default should be clamped, though... 15 seems a bit high for
> smaller IMAP servers *shrug*

--------8<-------
Subject: [PATCH] lei q|up: limit default write --jobs for IMAP(S)

IMAP(S) servers often limit per-user connections, so avoid
bumping into limits to improve the out-of-the-box experience.
4 seems like a conservative default, since we already chose
that number for remote HTTP(S) endpoints.

Link: https://public-inbox.org/meta/20220910201958.GA12212@dcvr/
---
  /me having git-repack OOM due to excessive default pack.threads
  reminded me of this issue :x

 Documentation/lei-q.pod     | 4 ++--
 lib/PublicInbox/LeiQuery.pm | 7 +++++--
 2 files changed, 7 insertions(+), 4 deletions(-)

diff --git a/Documentation/lei-q.pod b/Documentation/lei-q.pod
index 8134223e..d52c5b04 100644
--- a/Documentation/lei-q.pod
+++ b/Documentation/lei-q.pod
@@ -135,8 +135,8 @@ Set the number of query and write worker processes for parallelism.
 C<QUERY_WORKERS> defaults to the number of CPUs available, but 4 per
 remote (HTTP/HTTPS) host.
 
-C<WRITE_WORKERS> defaults to the number of CPUs available for Maildir,
-IMAP/IMAPS, and mbox* destinations.
+C<WRITE_WORKERS> defaults to 75% of the number of CPUs available for
+Maildir and mbox* destinations, but 4 per IMAP/IMAPS host.
 
 Omitting C<QUERY_WORKERS> but leaving the comma (C<,>) allows
 one to only set C<WRITE_WORKERS>
diff --git a/lib/PublicInbox/LeiQuery.pm b/lib/PublicInbox/LeiQuery.pm
index df9c32b3..0f839236 100644
--- a/lib/PublicInbox/LeiQuery.pm
+++ b/lib/PublicInbox/LeiQuery.pm
@@ -39,8 +39,11 @@ sub _start_query { # used by "lei q" and "lei up"
 			$lms->lms_write_prepare->lms_pause; # just create
 		}
 	}
-	$l2m and $l2m->{-wq_nr_workers} //= $mj //
-		int($nproc * 0.75 + 0.5); # keep some CPU for git
+	$l2m and $l2m->{-wq_nr_workers} //= $mj // do {
+		# keep some CPU for git, and don't overload IMAP destinations
+		my $n = int($nproc * 0.75 + 0.5);
+		$self->{net} && $n > 4 ? 4 : $n;
+	};
 
 	# descending docid order is cheapest, MUA controls sorting order
 	$self->{mset_opt}->{relevance} //= -2 if $l2m || $opt->{threads};

      reply	other threads:[~2022-11-14  8:07 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-09-09 10:09 imap: "Can't use an undefined value as a subroutine reference" Ricardo Ribalda
2022-09-09 17:44 ` [PATCH] lei: add diagnostics for IMAP writer failures Eric Wong
2022-09-09 18:00   ` [PATCH] doc: document --jobs for `lei q' and `lei up' Eric Wong
2022-09-09 20:35   ` [PATCH] lei: add diagnostics for IMAP writer failures Ricardo Ribalda
2022-09-10  1:18     ` [PATCH v2] lei: bail out earlier on " Eric Wong
2022-09-10 19:34       ` Ricardo Ribalda
2022-09-10 19:50         ` Eric Wong
2022-09-10 19:53           ` Ricardo Ribalda
2022-09-10 20:19             ` Eric Wong
2022-11-14  8:07               ` Eric Wong [this message]

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