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fix: invalidate NodeRange caches inherited across fork

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xcatd forks child processes to handle plugin requests. The child
inherits NodeRange.pm's module-level caches (@allnodeset, %allgrphash,
@grplist) with their timestamps from the parent. If the parent had
populated these caches within the past 5 seconds, the child reuses
stale data that does not reflect database changes committed by other
requests that completed between cache population and the fork.

This causes non-deterministic failures in group-definition regression
tests (chdef_group, mkdef_group, rmdef_group) where lsdef -s runs
noderange expansion inside the forked plugin process and hits the
inherited stale cache that predates the mkdef -t group commit.

Track the PID at cache-build time and treat any cache built by a
different PID as expired, forcing a fresh database read in children.
This commit is contained in:
Vinícius Ferrão
2026-05-02 19:10:01 -03:00
parent 10c13a3635
commit f139904c3e
1 changed files with 17 additions and 5 deletions
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22
perl-xCAT/xCAT/NodeRange.pm
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@@ -41,8 +41,11 @@ my $glstamp = 0;
my $allnodesetstamp = 0;
my $allgrphashstamp = 0;
my %allgrphash;
my $retaincache = 0;
my $recurselevel = 0;
my $retaincache = 0;
my $recurselevel = 0;
my $nodeset_pid = 0;
my $grplist_pid = 0;
my $allgrphash_pid = 0;
my @cachedcolumns;
@@ -74,6 +77,9 @@ sub reset_db {
#workaround, something seems to be trying to use a corrupted reference to grptab
#this allows init_dbworker to reset the object
$grptab = 0;
$nodeset_pid = 0;
$grplist_pid = 0;
$allgrphash_pid = 0;
}
sub nodesbycriteria {
@@ -200,7 +206,8 @@ sub nodesbycriteria {
sub expandatom {
my $atom = shift;
if ($recurselevel > 4096) { die "NodeRange seems to be hung on evaluating $atom, recursion limit hit"; }
unless (scalar(@allnodeset) and (($allnodesetstamp + 5) > time())) { #Build a cache of all nodes, some corner cases will perform worse, but by and large it will do better. We could do tests to see where the breaking points are, and predict how many atoms we have to evaluate to mitigate, for now, implement the strategy that keeps performance from going completely off the rails
unless (scalar(@allnodeset) and (($allnodesetstamp + 5) > time()) and $nodeset_pid == $$) { #Build a cache of all nodes, some corner cases will perform worse, but by and large it will do better. We could do tests to see where the breaking points are, and predict how many atoms we have to evaluate to mitigate, for now, implement the strategy that keeps performance from going completely off the rails
$nodeset_pid = $$;
$allnodesetstamp = time();
$nodelist->_set_use_cache(1);
@allnodeset = $nodelist->getAllAttribs('node', 'groups');
@@ -234,7 +241,8 @@ sub expandatom {
unless ($grptab) {
$grptab = xCAT::Table->new('nodegroup');
}
if ($grptab and (($glstamp < (time() - 5)) or (not $didgrouplist and not scalar @grplist))) {
if ($grptab and (($glstamp < (time() - 5)) or $grplist_pid != $$ or (not $didgrouplist and not scalar @grplist))) {
$grplist_pid = $$;
$didgrouplist = 1;
$glstamp = time();
my $grplist_ptr = $grptab->getAllEntries();
@@ -270,7 +278,8 @@ sub expandatom {
# The atom is not a dynamic node group, is it a static node group???
if (!$isdynamicgrp)
{
unless (scalar %allgrphash and (time() < ($allgrphashstamp + 5))) { #build a group membership cache
unless (scalar %allgrphash and (time() < ($allgrphashstamp + 5)) and $allgrphash_pid == $$) { #build a group membership cache
$allgrphash_pid = $$;
$allgrphashstamp = time();
%allgrphash = ();
my $nlent;
@@ -488,6 +497,9 @@ sub retain_cache { #A semi private operation to be used *ONLY* in the interestin
unless ($retaincache) { #take a call to retain_cache(0) to also mean that any existing
#cache must be zapped
if ($nodelist) { $nodelist->_build_cache(1); }
$nodeset_pid = 0;
$grplist_pid = 0;
$allgrphash_pid = 0;
$glstamp = 0;
$allnodesetstamp = 0;
$allgrphashstamp = 0;