* [PATCH 3/3] xapcmd: increase scope of lock
2020-01-26 1:17 7% [PATCH 0/3] writing/admin code cleanups lock fix Eric Wong
@ 2020-01-26 1:17 7% ` Eric Wong
0 siblings, 0 replies; 2+ results
From: Eric Wong @ 2020-01-26 1:17 UTC (permalink / raw)
To: meta
The old lock scope was only sufficient for protecting against
concurrent modifications from the common -mda, -watch, or -learn
writers.
It was not sufficient for protecting against parallel -compact
or -xcpdb invocations from eager admins. Most of the time this
only leads to confusing and misleading warning messages, but
parallel xcpdb --reshard could lead to errors.
---
lib/PublicInbox/Xapcmd.pm | 59 +++++++++++++++++++++------------------
1 file changed, 32 insertions(+), 27 deletions(-)
diff --git a/lib/PublicInbox/Xapcmd.pm b/lib/PublicInbox/Xapcmd.pm
index 19c6ff07..2864b0d4 100644
--- a/lib/PublicInbox/Xapcmd.pm
+++ b/lib/PublicInbox/Xapcmd.pm
@@ -122,7 +122,8 @@ sub same_fs_or_die ($$) {
}
sub process_queue {
- my ($queue, $cb, $max, $opt) = @_;
+ my ($queue, $cb, $opt) = @_;
+ my $max = $opt->{jobs} || scalar(@$queue);
if ($max <= 1) {
while (defined(my $args = shift @$queue)) {
$cb->($args, $opt);
@@ -152,36 +153,18 @@ sub setup_signals () {
$SIG{HUP} = $SIG{PIPE} = $SIG{TERM} = sub { exit(1) };
}
-sub run {
- my ($ibx, $task, $opt) = @_; # task = 'cpdb' or 'compact'
- my $cb = \&${\"PublicInbox::Xapcmd::$task"};
- PublicInbox::Admin::progress_prepare($opt ||= {});
- my $dir = $ibx->{inboxdir} or die "no inboxdir in inbox\n";
- runnable_or_die($XAPIAN_COMPACT) if $opt->{compact};
- my $reindex; # v1:{ from => $x40 }, v2:{ from => [ $x40, $x40, .. ] } }
- my $from; # per-epoch ranges
-
- if (!$opt->{-coarse_lock}) {
- $reindex = $opt->{reindex} = {};
- $from = $reindex->{from} = [];
- require PublicInbox::SearchIdx;
- PublicInbox::SearchIdx::load_xapian_writable();
- }
+sub prepare_run {
+ my ($ibx, $opt) = @_;
+ my $tmp = {}; # old shard dir => File::Temp->newdir object or undef
+ my @queue; # ([old//src,newdir]) - list of args for cpdb() or compact()
- $ibx->umask_prepare;
my $old = $ibx->search->xdir(1);
-d $old or die "$old does not exist\n";
-
- my $tmp = {};
- my @q;
my $reshard = $opt->{reshard};
if (defined $reshard && $reshard <= 0) {
die "--reshard must be a positive number\n";
}
- local %SIG = %SIG;
- setup_signals();
-
# we want temporary directories to be as deep as possible,
# so v2 shards can keep "xap$SCHEMA_VERSION" on a separate FS.
if ($ibx->version == 1) {
@@ -194,7 +177,7 @@ sub run {
my $v = PublicInbox::Search::SCHEMA_VERSION();
my $wip = File::Temp->newdir("xapian$v-XXXXXXXX", DIR => $dir);
$tmp->{$old} = $wip;
- push @q, [ $old, $wip ];
+ push @queue, [ $old, $wip ];
} else {
opendir my $dh, $old or die "Failed to opendir $old: $!\n";
my @old_shards;
@@ -223,7 +206,7 @@ sub run {
my $wip = File::Temp->newdir($tmpl, DIR => $old);
same_fs_or_die($old, $wip->dirname);
my $cur = "$old/$dn";
- push @q, [ $src // $cur , $wip ];
+ push @queue, [ $src // $cur , $wip ];
$tmp->{$cur} = $wip;
}
# mark old shards to be unlinked
@@ -231,10 +214,32 @@ sub run {
$tmp->{$_} ||= undef for @$src;
}
}
- my $max = $opt->{jobs} || scalar(@q);
+ ($tmp, \@queue);
+}
+
+sub run {
+ my ($ibx, $task, $opt) = @_; # task = 'cpdb' or 'compact'
+ my $cb = \&${\"PublicInbox::Xapcmd::$task"};
+ PublicInbox::Admin::progress_prepare($opt ||= {});
+ defined(my $dir = $ibx->{inboxdir}) or die "no inboxdir defined\n";
+ -d $dir or die "inboxdir=$dir does not exist\n";
+ runnable_or_die($XAPIAN_COMPACT) if $opt->{compact};
+ my $reindex; # v1:{ from => $x40 }, v2:{ from => [ $x40, $x40, .. ] } }
+
+ if (!$opt->{-coarse_lock}) {
+ $reindex = $opt->{reindex} = {};
+ $reindex->{from} = []; # per-epoch ranges
+ require PublicInbox::SearchIdx;
+ PublicInbox::SearchIdx::load_xapian_writable();
+ }
+
+ local %SIG = %SIG;
+ setup_signals();
+ $ibx->umask_prepare;
$ibx->with_umask(sub {
my $im = $ibx->importer(0);
$im->lock_acquire;
+ my ($tmp, $queue) = prepare_run($ibx, $opt);
# fine-grained locking if we prepare for reindex
if (!$opt->{-coarse_lock}) {
@@ -243,7 +248,7 @@ sub run {
}
$ibx->cleanup;
- process_queue(\@q, $cb, $max, $opt);
+ process_queue($queue, $cb, $opt);
$im->lock_acquire if !$opt->{-coarse_lock};
commit_changes($ibx, $im, $tmp, $opt);
});
^ permalink raw reply related [relevance 7%]
* [PATCH 0/3] writing/admin code cleanups lock fix
@ 2020-01-26 1:17 7% Eric Wong
2020-01-26 1:17 7% ` [PATCH 3/3] xapcmd: increase scope of lock Eric Wong
0 siblings, 1 reply; 2+ results
From: Eric Wong @ 2020-01-26 1:17 UTC (permalink / raw)
To: meta
I accidentally did some parallel -compact runs and noticed some
confusing (though harmless) errors. It could be harmful if
-xcpdb is running reshard, though, but I don't do that much.
There's also some cleanups leading up to it since I got tired of
looking at '||' and '//' all over the code.
Eric Wong (3):
inbox: add ->version method
search: {version} => {ibx_ver}
xapcmd: increase scope of lock
lib/PublicInbox/Admin.pm | 5 +--
lib/PublicInbox/AltId.pm | 2 +-
lib/PublicInbox/Feed.pm | 2 +-
lib/PublicInbox/Inbox.pm | 11 +++---
lib/PublicInbox/InboxWritable.pm | 9 ++---
lib/PublicInbox/Search.pm | 6 +--
lib/PublicInbox/SearchIdx.pm | 6 +--
lib/PublicInbox/Xapcmd.pm | 64 +++++++++++++++++---------------
script/public-inbox-convert | 2 +-
scripts/import_slrnspool | 2 +-
10 files changed, 56 insertions(+), 53 deletions(-)
^ permalink raw reply [relevance 7%]
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