File apache2-mod_jk-1.2.43-lb_retries.patch of Package apache2-mod_jk.15126
commit a52691efec2e784ec496f145acc4230ea2c8e14c
Author: Mark Thomas <markt@apache.org>
Date: Fri Aug 24 12:12:27 2018 +0000
Fix https://bz.apache.org/bugzilla/show_bug.cgi?id=62408
Add the new load-balancer worker property lb_retries to improve the control over the number of retries.
Based on a patch provided by Frederik Nosi.
git-svn-id: https://svn.apache.org/repos/asf/tomcat/jk/trunk@1838830 13f79535-47bb-0310-9956-ffa450edef68
Index: tomcat-connectors-1.2.43-src/native/common/jk_ajp_common.c
===================================================================
--- tomcat-connectors-1.2.43-src.orig/native/common/jk_ajp_common.c
+++ tomcat-connectors-1.2.43-src/native/common/jk_ajp_common.c
@@ -3044,6 +3044,10 @@ int ajp_init(jk_worker_t *pThis,
jk_get_worker_retries(props, p->name,
JK_RETRIES);
+ p->lb_retries =
+ jk_get_worker_lb_retries(props, p->name,
+ JK_LB_RETRIES);
+
p->max_packet_size =
jk_get_max_packet_size(props, p->name);
Index: tomcat-connectors-1.2.43-src/native/common/jk_ajp_common.h
===================================================================
--- tomcat-connectors-1.2.43-src.orig/native/common/jk_ajp_common.h
+++ tomcat-connectors-1.2.43-src/native/common/jk_ajp_common.h
@@ -370,6 +370,13 @@ struct ajp_worker
*/
int retries;
+ /*
+ * Public property used in load balancer workers, meaning
+ * the maximum number of failover attempts between ajp
+ * workers of cluster.
+ */
+ int lb_retries;
+
unsigned int max_packet_size; /* Maximum AJP Packet size */
int retry_interval; /* Number of milliseconds to sleep before doing a retry */
Index: tomcat-connectors-1.2.43-src/native/common/jk_lb_worker.c
===================================================================
--- tomcat-connectors-1.2.43-src.orig/native/common/jk_lb_worker.c
+++ tomcat-connectors-1.2.43-src/native/common/jk_lb_worker.c
@@ -1225,6 +1225,7 @@ static int JK_METHOD service(jk_endpoint
if (p->worker->sequence < p->worker->s->h.sequence)
jk_lb_pull(p->worker, JK_FALSE, l);
for (i = 0; i < num_of_workers; i++) {
+ jk_log(l, JK_LOG_DEBUG, "LB - num_of_workers: %d, retry: %d, lb_retries: %d", num_of_workers, i, p->worker->lb_retries);
lb_sub_worker_t *rec = &(p->worker->lb_workers[i]);
ajp_worker_t *aw = (ajp_worker_t *)rec->worker->worker_private;
if (rec->s->state == JK_LB_STATE_BUSY) {
@@ -1272,7 +1273,10 @@ static int JK_METHOD service(jk_endpoint
p->worker->sticky_session, sessionid ? sessionid : "empty");
while (recoverable == JK_TRUE) {
- if (attempt >= num_of_workers) {
+ if (JK_IS_DEBUG_LEVEL(l))
+ jk_log(l, JK_LOG_DEBUG, "attempt %d, max attempts %d, worker count %d",
+ attempt, p->worker->lb_retries, num_of_workers);
+ if (attempt >= num_of_workers || attempt >= p->worker->lb_retries) {
retry++;
if (retry >= p->worker->retries) {
/* Done with retrying */
@@ -1549,7 +1553,7 @@ static int JK_METHOD service(jk_endpoint
}
else {
/*
- * Reply timeout, bot not yet too many of them.
+ * Reply timeout, but not yet too many of them.
* Keep previous global state.
* Do not try to reuse the same node for the same request.
* Failing over to another node could help.
@@ -1903,6 +1907,8 @@ static int JK_METHOD init(jk_worker_t *p
p->worker.we = we;
p->retries = jk_get_worker_retries(props, p->name,
JK_RETRIES);
+ p->lb_retries = jk_get_worker_lb_retries(props, p->name,
+ JK_LB_RETRIES);
p->retry_interval =
jk_get_worker_retry_interval(props, p->name,
JK_SLEEP_DEF);
Index: tomcat-connectors-1.2.43-src/native/common/jk_lb_worker.h
===================================================================
--- tomcat-connectors-1.2.43-src.orig/native/common/jk_lb_worker.h
+++ tomcat-connectors-1.2.43-src/native/common/jk_lb_worker.h
@@ -187,6 +187,7 @@ struct lb_worker
int error_escalation_time;
int max_reply_timeouts;
int retries;
+ int lb_retries;
int retry_interval;
int lbmethod;
int lblock;
Index: tomcat-connectors-1.2.43-src/native/common/jk_service.h
===================================================================
--- tomcat-connectors-1.2.43-src.orig/native/common/jk_service.h
+++ tomcat-connectors-1.2.43-src/native/common/jk_service.h
@@ -36,6 +36,7 @@
#include "jk_msg_buff.h"
#define JK_RETRIES 2
+#define JK_LB_RETRIES 2
#ifdef __cplusplus
extern "C"
Index: tomcat-connectors-1.2.43-src/native/common/jk_util.c
===================================================================
--- tomcat-connectors-1.2.43-src.orig/native/common/jk_util.c
+++ tomcat-connectors-1.2.43-src/native/common/jk_util.c
@@ -111,6 +111,7 @@
#define DEFAULT_WORKER_TYPE JK_AJP13_WORKER_NAME
#define SECRET_KEY_OF_WORKER "secretkey"
#define RETRIES_OF_WORKER "retries"
+#define LB_RETRIES_OF_WORKER "lb_retries"
#define STATUS_FAIL_OF_WORKER "fail_on_status"
#define DEFAULT_WORKER JK_AJP13_WORKER_NAME
@@ -232,6 +233,7 @@ static const char *unique_properties[] =
STYLE_SHEET_OF_WORKER,
READ_ONLY_OF_WORKER,
RETRIES_OF_WORKER,
+ LB_RETRIES_OF_WORKER,
WORKER_MAINTAIN_PROPERTY_NAME,
NAMESPACE_OF_WORKER,
XML_NAMESPACE_OF_WORKER,
@@ -342,6 +344,7 @@ static const char *supported_properties[
BAD_RATING_OF_WORKER,
SECRET_KEY_OF_WORKER,
RETRIES_OF_WORKER,
+ LB_RETRIES_OF_WORKER,
STATUS_FAIL_OF_WORKER,
LIST_PROPERTY_NAME,
MAINTAIN_PROPERTY_NAME,
@@ -1245,6 +1248,24 @@ int jk_get_worker_retries(jk_map_t *m, c
return rv;
}
+int jk_get_worker_lb_retries(jk_map_t *m, const char *wname, int def)
+{
+ char buf[1024];
+ int rv;
+ if (!m || !wname) {
+ return -1;
+ }
+
+ MAKE_WORKER_PARAM(LB_RETRIES_OF_WORKER);
+
+ rv = jk_map_get_int(m, buf, def);
+ if (rv < 1)
+ rv = 1;
+
+ return rv;
+}
+
+
int jk_get_worker_recovery_opts(jk_map_t *m, const char *wname, int def)
{
char buf[PARAM_BUFFER_SIZE];
Index: tomcat-connectors-1.2.43-src/xdocs/reference/workers.xml
===================================================================
--- tomcat-connectors-1.2.43-src.orig/xdocs/reference/workers.xml
+++ tomcat-connectors-1.2.43-src/xdocs/reference/workers.xml
@@ -626,15 +626,59 @@ This feature has been added in <b>jk 1.2
<directive name="retries" default="2" required="false">
<warn>This directive also exists for normal workers.
-For those it has a <a href="#Advanced Worker Directives">different meaning</a>.</warn>
-If the load balancer can not get a valid member worker or in case of failover,
-it will try again a number of times given by <b>retries</b>.
-Before each retry, it will make a pause define by <b>retry_interval</b> directive.
+For those it has a <a href="#Advanced Worker Directives">different
+meaning</a>.</warn>
+When making a request, the load-balancer worker will allocate the request to a
+member worker. If that member worker is either unable to service the request or
+fails to service the request, the request will be passed to another member
+worker until the request is processed, every member worker has attempted to
+process the request or <b>lb_retries</b> member workers have attempted to
+process the request.
+<p>
+If the request remains unprocessed, the load-balancer worker will repeat the
+above process a maximum of <b>retries</b> times (including the original
+attempt). Before each retry, the load-balancer worker will pause for a time
+defined by the <b>retry_interval</b> directive.
+</p>
+<p>
+ Note that this means that, if all workers fail, there will be a total of
+worker.retries * min(lb.lb_retries,member worker count) * lb.retries requests
+before a 504 response is returned to the client. So for an lb worker with four
+members and a default configuration, if all workers fail there will be a total
+of 8 requests before a 504 response is returned to the client.
+</p>
<p>
Until version <b>1.2.16</b> the default value was 3.
</p>
</directive>
+<directive name="lb_retries" default="2" required="false">
+When making a request, the load-balancer worker will allocate the request to a
+member worker. If that member worker is either unable to service the request or
+fails to service the request, the request will be passed to another member
+worker until the request is processed, every member worker has attempted to
+process the request or <b>lb_retries</b> member workers have attempted to
+ process the request.
+<p>
+If the request remains unprocessed, the load-balancer worker will repeat the
+above process a maximum of <b>retries</b> times (including the original
+attempt). Before each retry, the load-balancer worker will pause for a time
+defined by the <b>retry_interval</b> directive.
+</p>
+<p>
+Note that this means that, if all workers fail, there will be a total of
+worker.retries * min(lb.lb_retries,member worker count) * lb.retries requests
+before a 504 response is returned to the client. So for an lb worker with four
+members and a default configuration, if all workers fail there will be a total
+of 8 requests before a 504 response is returned to the client.
+</p>
+<p>
+This feature has been added in <b>jk 1.2.44</b>. Prior to this feature being
+added, the load-balancer worker behaved as if <b>lb_retries</b> was equal to the
+number of member workers.
+</p>
+</directive>
+
</directives>
</subsection>
Index: tomcat-connectors-1.2.43-src/native/common/jk_util.h
===================================================================
--- tomcat-connectors-1.2.43-src.orig/native/common/jk_util.h
+++ tomcat-connectors-1.2.43-src/native/common/jk_util.h
@@ -131,6 +131,8 @@ const char *jk_get_lb_session_cookie_pat
int jk_get_worker_retries(jk_map_t *m, const char *wname, int def);
+int jk_get_worker_lb_retries(jk_map_t *m, const char *wname, int def);
+
int jk_get_is_worker_disabled(jk_map_t *m, const char *wname);
int jk_get_is_worker_stopped(jk_map_t *m, const char *wname);
