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Posted to cvs@httpd.apache.org by tr...@apache.org on 2012/08/17 17:45:28 UTC
svn commit: r1374330 - in /httpd/httpd/branches/2.2.x: CHANGES STATUS
server/mpm/experimental/event/event.c server/mpm/worker/worker.c
Author: trawick
Date: Fri Aug 17 15:45:28 2012
New Revision: 1374330
URL: http://svn.apache.org/viewvc?rev=1374330&view=rev
Log:
mpm_event, mpm_worker: Remain active amidst prevalent child process
resource shortages.
Submitted by: trawick
Reviewed by: wrowe, rjung
Modified:
httpd/httpd/branches/2.2.x/CHANGES
httpd/httpd/branches/2.2.x/STATUS
httpd/httpd/branches/2.2.x/server/mpm/experimental/event/event.c
httpd/httpd/branches/2.2.x/server/mpm/worker/worker.c
Modified: httpd/httpd/branches/2.2.x/CHANGES
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.2.x/CHANGES?rev=1374330&r1=1374329&r2=1374330&view=diff
==============================================================================
--- httpd/httpd/branches/2.2.x/CHANGES [utf-8] (original)
+++ httpd/httpd/branches/2.2.x/CHANGES [utf-8] Fri Aug 17 15:45:28 2012
@@ -5,6 +5,9 @@ Changes with Apache 2.2.23
envvars: Fix insecure handling of LD_LIBRARY_PATH that could lead to the
current working directory to be searched for DSOs. [Stefan Fritsch]
+ *) mpm_event, mpm_worker: Remain active amidst prevalent child process
+ resource shortages. [Jeff Trawick]
+
*) mod_proxy_balancer: Restore balancing after a failed worker has
recovered when using lbmethod_bybusyness. PR 48735. [Jeff Trawick]
Modified: httpd/httpd/branches/2.2.x/STATUS
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.2.x/STATUS?rev=1374330&r1=1374329&r2=1374330&view=diff
==============================================================================
--- httpd/httpd/branches/2.2.x/STATUS (original)
+++ httpd/httpd/branches/2.2.x/STATUS Fri Aug 17 15:45:28 2012
@@ -112,14 +112,6 @@ PATCHES ACCEPTED TO BACKPORT FROM TRUNK:
2.2.x patch: http://people.apache.org/~jim/patches/mod_proxy_ajp-erroroverride.patch
+1: igalic, jim, rpluem
- * mpm_event, mpm_worker: Remain active amidst prevalent child process
- resource shortages.
- trunk patch: http://svn.apache.org/viewvc?rev=1363557&view=rev
- trunk patch: http://svn.apache.org/viewvc?rev=1364601&view=rev
- 2.4.x patch: trunk patch works
- 2.2.x patch: http://people.apache.org/~trawick/r1363557_1364601_to_2.2.x.txt
- +1: trawick, wrowe, rjung
-
PATCHES PROPOSED TO BACKPORT FROM TRUNK:
[ New proposals should be added at the end of the list ]
Modified: httpd/httpd/branches/2.2.x/server/mpm/experimental/event/event.c
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.2.x/server/mpm/experimental/event/event.c?rev=1374330&r1=1374329&r2=1374330&view=diff
==============================================================================
--- httpd/httpd/branches/2.2.x/server/mpm/experimental/event/event.c (original)
+++ httpd/httpd/branches/2.2.x/server/mpm/experimental/event/event.c Fri Aug 17 15:45:28 2012
@@ -148,6 +148,7 @@ static int ap_daemons_limit = 0;
static int server_limit = DEFAULT_SERVER_LIMIT;
static int first_server_limit = 0;
static int thread_limit = DEFAULT_THREAD_LIMIT;
+static int had_healthy_child = 0;
static int first_thread_limit = 0;
static int changed_limit_at_restart;
static int dying = 0;
@@ -1657,6 +1658,7 @@ static void perform_idle_server_maintena
int any_dying_threads = 0;
int any_dead_threads = 0;
int all_dead_threads = 1;
+ int child_threads_active = 0;
if (i >= ap_max_daemons_limit
&& totally_free_length == idle_spawn_rate)
@@ -1686,10 +1688,11 @@ static void perform_idle_server_maintena
++idle_thread_count;
}
if (status >= SERVER_READY && status < SERVER_GRACEFUL) {
- ++active_thread_count;
+ ++child_threads_active;
}
}
}
+ active_thread_count += child_threads_active;
if (any_dead_threads
&& totally_free_length < idle_spawn_rate
&& free_length < MAX_SPAWN_RATE
@@ -1713,6 +1716,9 @@ static void perform_idle_server_maintena
}
++free_length;
}
+ else if (child_threads_active == ap_threads_per_child) {
+ had_healthy_child = 1;
+ }
/* XXX if (!ps->quiescing) is probably more reliable GLA */
if (!any_dying_threads) {
last_non_dead = i;
@@ -1721,21 +1727,23 @@ static void perform_idle_server_maintena
}
if (sick_child_detected) {
- if (active_thread_count > 0) {
- /* some child processes appear to be working. don't kill the
- * whole server.
+ if (had_healthy_child) {
+ /* Assume this is a transient error, even though it may not be. Leave
+ * the server up in case it is able to serve some requests or the
+ * problem will be resolved.
*/
sick_child_detected = 0;
}
else {
- /* looks like a basket case. give up.
+ /* looks like a basket case, as no child ever fully initialized; give up.
*/
shutdown_pending = 1;
child_fatal = 1;
ap_log_error(APLOG_MARK, APLOG_ALERT, 0,
ap_server_conf,
- "No active workers found..."
- " Apache is exiting!");
+ "A resource shortage or other unrecoverable failure "
+ "was encountered before any child process initialized "
+ "successfully... httpd is exiting!");
/* the child already logged the failure details */
return;
}
@@ -2198,6 +2206,7 @@ static int worker_pre_config(apr_pool_t
ap_pid_fname = DEFAULT_PIDLOG;
ap_lock_fname = DEFAULT_LOCKFILE;
ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
+ had_healthy_child = 0;
ap_extended_status = 0;
#ifdef AP_MPM_WANT_SET_MAX_MEM_FREE
ap_max_mem_free = APR_ALLOCATOR_MAX_FREE_UNLIMITED;
Modified: httpd/httpd/branches/2.2.x/server/mpm/worker/worker.c
URL: http://svn.apache.org/viewvc/httpd/httpd/branches/2.2.x/server/mpm/worker/worker.c?rev=1374330&r1=1374329&r2=1374330&view=diff
==============================================================================
--- httpd/httpd/branches/2.2.x/server/mpm/worker/worker.c (original)
+++ httpd/httpd/branches/2.2.x/server/mpm/worker/worker.c Fri Aug 17 15:45:28 2012
@@ -124,6 +124,7 @@ static int first_server_limit = 0;
static int thread_limit = DEFAULT_THREAD_LIMIT;
static int first_thread_limit = 0;
static int changed_limit_at_restart;
+static int had_healthy_child = 0;
static int dying = 0;
static int workers_may_exit = 0;
static int start_thread_may_exit = 0;
@@ -1419,6 +1420,7 @@ static void perform_idle_server_maintena
int any_dying_threads = 0;
int any_dead_threads = 0;
int all_dead_threads = 1;
+ int child_threads_active = 0;
if (i >= ap_max_daemons_limit && totally_free_length == idle_spawn_rate)
break;
@@ -1449,10 +1451,11 @@ static void perform_idle_server_maintena
++idle_thread_count;
}
if (status >= SERVER_READY && status < SERVER_GRACEFUL) {
- ++active_thread_count;
+ ++child_threads_active;
}
}
}
+ active_thread_count += child_threads_active;
if (any_dead_threads && totally_free_length < idle_spawn_rate
&& free_length < MAX_SPAWN_RATE
&& (!ps->pid /* no process in the slot */
@@ -1475,6 +1478,9 @@ static void perform_idle_server_maintena
}
++free_length;
}
+ else if (child_threads_active == ap_threads_per_child) {
+ had_healthy_child = 1;
+ }
/* XXX if (!ps->quiescing) is probably more reliable GLA */
if (!any_dying_threads) {
last_non_dead = i;
@@ -1483,21 +1489,23 @@ static void perform_idle_server_maintena
}
if (sick_child_detected) {
- if (active_thread_count > 0) {
- /* some child processes appear to be working. don't kill the
- * whole server.
+ if (had_healthy_child) {
+ /* Assume this is a transient error, even though it may not be. Leave
+ * the server up in case it is able to serve some requests or the
+ * problem will be resolved.
*/
sick_child_detected = 0;
}
else {
- /* looks like a basket case. give up.
+ /* looks like a basket case, as no child ever fully initialized; give up.
*/
shutdown_pending = 1;
child_fatal = 1;
ap_log_error(APLOG_MARK, APLOG_ALERT, 0,
ap_server_conf,
- "No active workers found..."
- " Apache is exiting!");
+ "A resource shortage or other unrecoverable failure "
+ "was encountered before any child process initialized "
+ "successfully... httpd is exiting!");
/* the child already logged the failure details */
return;
}
@@ -2011,6 +2019,7 @@ static int worker_pre_config(apr_pool_t
ap_pid_fname = DEFAULT_PIDLOG;
ap_lock_fname = DEFAULT_LOCKFILE;
ap_max_requests_per_child = DEFAULT_MAX_REQUESTS_PER_CHILD;
+ had_healthy_child = 0;
ap_extended_status = 0;
#ifdef AP_MPM_WANT_SET_MAX_MEM_FREE
ap_max_mem_free = APR_ALLOCATOR_MAX_FREE_UNLIMITED;