X-Git-Url: http://www.git.stargrave.org/?a=blobdiff_plain;f=Documentation%2Fpublic-inbox-tuning.pod;h=67316fb11109b4071197a2db9788dc254eb9a1d0;hb=f3d0e746c6a35c8600b91af99958a52cbc114a4b;hp=e3f2899b76e58d90a22934f1d772beb3e8516816;hpb=78b1c973fba89bc6651ffa16807c40abd38e7bad;p=public-inbox.git

diff --git a/Documentation/public-inbox-tuning.pod b/Documentation/public-inbox-tuning.pod
index e3f2899b..67316fb1 100644
--- a/Documentation/public-inbox-tuning.pod
+++ b/Documentation/public-inbox-tuning.pod
@@ -34,6 +34,10 @@ Performance on solid state drives
 
 Read-only daemons
 
+=item 7
+
+Other OS tuning knobs
+
 =back
 
 =head2 New inboxes: public-inbox-init -V2
@@ -55,6 +59,15 @@ public-inbox processes.
 More (optional) L<Inline::C> 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<Inline::C>
+is enabled (described above), per-inbox C<git cat-file --batch>
+processes are replaced with a single L<perl(1)> process running
+C<PublicInbox::Gcf2::loop> in read-only daemons.
+
+Available as of public-inbox 1.7.0.
+
 =head2 Performance on rotational hard disk drives
 
 Random I/O performance is poor on rotational HDDs.  Xapian indexing
@@ -74,7 +87,7 @@ sharding imposes a performance penalty for read-only queries.
 
 Users with large amounts of RAM are advised to set a large value
 for C<publicinbox.indexBatchSize> as documented in
-L<public-inbox-config(5)>.
+L<public-inbox-index(1)>.
 
 C<dm-crypt> users on Linux 4.0+ are advised to try the
 C<--perf-same_cpu_crypt> C<--perf-submit_from_crypt_cpus>
@@ -95,7 +108,9 @@ Disabling copy-on-write also disables checksumming, thus C<raid1>
 Fortunately, these SQLite and Xapian indices are designed to
 recoverable from git if missing.
 
-Disabling CoW does not prevent all fragmentation.
+Disabling CoW does not prevent all fragmentation.  Large values
+of C<publicInbox.indexBatchSize> also limit fragmentation during
+the initial index.
 
 Avoid snapshotting subvolumes containing Xapian and/or SQLite indices.
 Snapshots use CoW despite our efforts to disable it, resulting
@@ -131,12 +146,21 @@ for parallelism.
 
 The open file descriptor limit (C<RLIMIT_NOFILE>, C<ulimit -n> in L<sh(1)>,
 C<LimitNOFILE=> in L<systemd.exec(5)>) may need to be raised to
-accomodate many concurrent clients.
+accommodate many concurrent clients.
 
 Transport Layer Security (IMAPS, NNTPS, or via STARTTLS) significantly
 increases memory use of client sockets, sure to account for that in
 capacity planning.
 
+=head2 Other OS tuning knobs
+
+Linux users: the C<sys.vm.max_map_count> sysctl may need to be increased if
+handling thousands of inboxes (with L<public-inbox-extindex(1)>) to avoid
+out-of-memory errors from git.
+
+Other OSes may have similar tuning knobs (patches appreciated).
+
+
 =head1 CONTACT
 
 Feedback encouraged via plain-text mail to L<mailto:meta@public-inbox.org>
@@ -145,10 +169,10 @@ Information for *BSDs and non-traditional filesystems especially
 welcome.
 
 Our archives are hosted at L<https://public-inbox.org/meta/>,
-L<http://hjrcffqmbrq6wope.onion/meta/>, and other places
+L<http://4uok3hntl7oi7b4uf4rtfwefqeexfzil2w6kgk2jn5z2f764irre7byd.onion/meta/>, and other places
 
 =head1 COPYRIGHT
 
-Copyright 2020 all contributors L<mailto:meta@public-inbox.org>
+Copyright 2020-2021 all contributors L<mailto:meta@public-inbox.org>
 
 License: AGPL-3.0+ L<https://www.gnu.org/licenses/agpl-3.0.txt>