From: Bill Erickson <berickxx@gmail.com>
Date: Wed, 13 May 2020 17:55:43 +0000 (-0400)
Subject: LPXXX C listener backlog loop speedbump
X-Git-Url: https://old-git.evergreen-ils.org/?a=commitdiff_plain;h=refs%2Fheads%2Fuser%2Fberick%2Flpxxx-c-backlog-speedbump;p=working%2FOpenSRF.git

LPXXX C listener backlog loop speedbump

When the request backlog contains items in the C forking code, attempts
to process the request run in a tight loop without stopping until the
backlog is once again empty.  This can lead to spewing "Could not launch
a new child" warning messages at a high rate, saturating log files.

This commit adds a 1 second speed bump between backlog processing loops
to allow time for drones to complete their task and start processing the
remaining queued requests.  The delay has a secondary affect of limited
the speed of the warning log spewing.

This 1-second speedbump logic matches that of the Perl code.

Signed-off-by: Bill Erickson <berickxx@gmail.com>
---

diff --git a/src/libopensrf/osrf_prefork.c b/src/libopensrf/osrf_prefork.c
index a9f7c42..845a64e 100644
--- a/src/libopensrf/osrf_prefork.c
+++ b/src/libopensrf/osrf_prefork.c
@@ -885,8 +885,11 @@ static void prefork_run( prefork_simple* forker ) {
 			cur_msg = client_recv( forker->connection, -1 );
 			received_from_network = 1;
 		} else {
-			// See if any messages are immediately available
-			cur_msg = client_recv( forker->connection, 0 );
+			// We have queued messages, which means all of our drones
+			// are occupied.  See if any new messages are available on the
+			// network while waiting up to 1 second to allow time for a drone
+			// to become available to handle the next request in the queue.
+			cur_msg = client_recv( forker->connection, 1 );
 			if ( cur_msg != NULL )
 				received_from_network = 1;
 		}