From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on dcvr.yhbt.net X-Spam-Level: X-Spam-ASN: X-Spam-Status: No, score=-4.0 required=3.0 tests=ALL_TRUSTED,BAYES_00 shortcircuit=no autolearn=ham autolearn_force=no version=3.4.2 Received: from localhost (dcvr.yhbt.net [127.0.0.1]) by dcvr.yhbt.net (Postfix) with ESMTP id 6D1B01F8C8 for ; Sun, 19 Sep 2021 00:36:04 +0000 (UTC) From: Eric Wong To: meta@public-inbox.org Subject: [PATCH] doc: tuning: note git 2.33+, move libgit2 into Inline::C section Date: Sun, 19 Sep 2021 00:36:04 +0000 Message-Id: <20210919003604.20879-1-e@80x24.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit List-Id: git 2.33+ contains important optimizations for the thousands-of-inboxes case. And combine the Inline::C stuff with libgit2, since our use of libgit2 requires Inline::C. --- Documentation/public-inbox-tuning.pod | 29 ++++++++++++++++++--------- 1 file changed, 20 insertions(+), 9 deletions(-) diff --git a/Documentation/public-inbox-tuning.pod b/Documentation/public-inbox-tuning.pod index 67316fb1..7b18b3bc 100644 --- a/Documentation/public-inbox-tuning.pod +++ b/Documentation/public-inbox-tuning.pod @@ -16,7 +16,7 @@ New inboxes: public-inbox-init -V2 =item 2 -Process spawning +Optional Inline::C use =item 3 @@ -38,6 +38,10 @@ Read-only daemons Other OS tuning knobs +=item 8 + +Scalability to many inboxes + =back =head2 New inboxes: public-inbox-init -V2 @@ -46,7 +50,7 @@ If you're starting a new inbox (and not mirroring an existing one), the L<-V2|public-inbox-v2-format(5)> requires L, but is orders of magnitude more scalable than the original C<-V1> format. -=head2 Process spawning +=head2 Optional Inline::C use Our optional use of L speeds up subprocess spawning from large daemon processes. @@ -56,17 +60,16 @@ environment variable to point to a writable directory, or create C<~/.cache/public-inbox/inline-c> for any user(s) running public-inbox processes. -More (optional) L use will be introduced in the future -to lower memory use and improve scalability. - -=head2 libgit2 usage via Inline::C - If libgit2 development files are installed and L is enabled (described above), per-inbox C processes are replaced with a single L process running -C in read-only daemons. +C in read-only daemons. libgit2 use +will be available in public-inbox 1.7.0+ -Available as of public-inbox 1.7.0. +More (optional) L use will be introduced in the future +to lower memory use and improve scalability. + +Note: L is required for L, but not public-inbox-* =head2 Performance on rotational hard disk drives @@ -160,6 +163,14 @@ out-of-memory errors from git. Other OSes may have similar tuning knobs (patches appreciated). +=head2 Scalability to many inboxes + +git 2.33+ startup time is orders-of-magnitude faster and uses +less memory when dealing with thousands of alternates required +for thousands of inboxes. + +L allows any number of public-inboxes +to share the same Xapian indices. =head1 CONTACT