From 9d728db70a984803fc7e2b4d52e6a399f240c515 Mon Sep 17 00:00:00 2001 From: Galen Charlton Date: Thu, 2 Dec 2021 10:14:29 -0500 Subject: [PATCH] LP#1953047: don't try to kill children with non-numeric PIDs This patch band-aids around the following listener error that we've occassionally seen: server: died with error Can't kill a non-numeric process ID at .../OpenSRF/Server.pm line 335. With this patch, OpenSRF::Server->kill_child() will now simply log a warning rather than passing a non-numeric value to kill() This patch does not address the root cause, which is still unknown, but could include: - An actual failure to fork a new child leading to an undef PID ending up on the drone list. As OpenSRF::Server does not currently check for undef return from fork(), this cannot be dismissed, but this doesn't fit our observations. - Something akin to bug 1953044; in particular, there might be a race condition between ->reap_children(), ->check_status(), and ->handle_sighup() that results in an attempt to kill a child that's already been reaped. If so, the patch for bug 1953044 *might* also ameliorate this crash. To test ------- [1] Check logs to see if you've encountered the issue listed above. [2] Apply the patch and wait to see if the error ever recurs or if you see one of the two warnings in the log: refused to kill child with non-numeric PID $pid refused to kill child with undefined PID Signed-off-by: Galen Charlton --- src/perl/lib/OpenSRF/Server.pm | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/src/perl/lib/OpenSRF/Server.pm b/src/perl/lib/OpenSRF/Server.pm index 52c53d2..c7466a4 100644 --- a/src/perl/lib/OpenSRF/Server.pm +++ b/src/perl/lib/OpenSRF/Server.pm @@ -332,7 +332,16 @@ sub kill_child { my $self = shift; my $child = shift || pop(@{$self->{idle_list}}) or return; $chatty and $logger->internal("server: killing child $child"); - kill('TERM', $child->{pid}); + + if (defined($child->{pid})) { + if ($child->{pid} =~ /^-?\d+$/) { + kill('TERM', $child->{pid}); + } else { + $logger->warn("refused to kill child with non-numeric PID $child->{pid}"); + } + } else { + $logger->warn('refused to kill child with undefined PID'); + } } # ---------------------------------------------------------------- -- 2.11.0