Author: rjung
Date: Thu Sep 22 23:23:18 2011
New Revision: 1174449
URL: http://svn.apache.org/viewvc?rev=1174449&view=rev
Log:
Add the mapping rule extension "stateless" and analogous
HTTPD env var JK_STATELESS.
They can be used to improve session based load
balancing. We normally count any request without session
id as a new session. Requests known to not create a new
session can be marked using "stateless". They will not
influence the session balancing.
Those requests themselves will be distributed in a
round-robin way (but stickyness would be respected).
Modified:
tomcat/jk/trunk/native/apache-1.3/mod_jk.c
tomcat/jk/trunk/native/apache-2.0/mod_jk.c
tomcat/jk/trunk/native/common/jk_lb_worker.c
tomcat/jk/trunk/native/common/jk_service.h
tomcat/jk/trunk/native/common/jk_status.c
tomcat/jk/trunk/native/common/jk_uri_worker_map.c
tomcat/jk/trunk/native/common/jk_uri_worker_map.h
tomcat/jk/trunk/native/common/jk_util.c
tomcat/jk/trunk/native/iis/jk_isapi_plugin.c
tomcat/jk/trunk/xdocs/miscellaneous/changelog.xml
tomcat/jk/trunk/xdocs/reference/apache.xml
tomcat/jk/trunk/xdocs/reference/uriworkermap.xml
tomcat/jk/trunk/xdocs/reference/workers.xml
Modified: tomcat/jk/trunk/native/apache-1.3/mod_jk.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/apache-1.3/mod_jk.c?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/apache-1.3/mod_jk.c (original)
+++ tomcat/jk/trunk/native/apache-1.3/mod_jk.c Thu Sep 22 23:23:18 2011
@@ -80,6 +80,7 @@
#define JK_ENV_CERTCHAIN_PREFIX ("SSL_CLIENT_CERT_CHAIN_")
#define JK_ENV_REPLY_TIMEOUT ("JK_REPLY_TIMEOUT")
#define JK_ENV_STICKY_IGNORE ("JK_STICKY_IGNORE")
+#define JK_ENV_STATELESS ("JK_STATELESS")
#define JK_ENV_WORKER_NAME ("JK_WORKER_NAME")
#define JK_NOTE_WORKER_NAME ("JK_WORKER_NAME")
#define JK_NOTE_WORKER_TYPE ("JK_WORKER_TYPE")
@@ -681,6 +682,7 @@ static int init_ws_service(apache_privat
char *ssl_temp = NULL;
const char *reply_timeout = NULL;
const char *sticky_ignore = NULL;
+ const char *stateless = NULL;
rule_extension_t *e;
/* Copy in function pointers (which are really methods) */
@@ -729,6 +731,7 @@ static int init_ws_service(apache_privat
if (e) {
s->extension.reply_timeout = e->reply_timeout;
s->extension.sticky_ignore = e->sticky_ignore;
+ s->extension.stateless = e->stateless;
s->extension.use_server_error_pages = e->use_server_error_pages;
if (e->activation) {
s->extension.activation = ap_palloc(r->pool, e->activation_size *
sizeof(int));
@@ -763,6 +766,22 @@ static int init_ws_service(apache_privat
}
}
+ stateless = ap_table_get(r->subprocess_env, JK_ENV_STATELESS);
+ if (stateless) {
+ if (*stateless == '\0') {
+ s->extension.stateless = JK_TRUE;
+ }
+ else {
+ int r = atoi(stateless);
+ if (r) {
+ s->extension.stateless = JK_TRUE;
+ }
+ else {
+ s->extension.stateless = JK_FALSE;
+ }
+ }
+ }
+
if (conf->options & JK_OPT_DISABLEREUSE)
s->disable_reuse = 1;
Modified: tomcat/jk/trunk/native/apache-2.0/mod_jk.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/apache-2.0/mod_jk.c?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/apache-2.0/mod_jk.c (original)
+++ tomcat/jk/trunk/native/apache-2.0/mod_jk.c Thu Sep 22 23:23:18 2011
@@ -115,6 +115,7 @@
#define JK_ENV_CERTCHAIN_PREFIX ("SSL_CLIENT_CERT_CHAIN_")
#define JK_ENV_REPLY_TIMEOUT ("JK_REPLY_TIMEOUT")
#define JK_ENV_STICKY_IGNORE ("JK_STICKY_IGNORE")
+#define JK_ENV_STATELESS ("JK_STATELESS")
#define JK_ENV_WORKER_NAME ("JK_WORKER_NAME")
#define JK_NOTE_WORKER_NAME ("JK_WORKER_NAME")
#define JK_NOTE_WORKER_TYPE ("JK_WORKER_TYPE")
@@ -736,6 +737,7 @@ static int init_ws_service(apache_privat
char *ssl_temp = NULL;
const char *reply_timeout = NULL;
const char *sticky_ignore = NULL;
+ const char *stateless = NULL;
rule_extension_t *e;
/* Copy in function pointers (which are really methods) */
@@ -783,6 +785,7 @@ static int init_ws_service(apache_privat
if (e) {
s->extension.reply_timeout = e->reply_timeout;
s->extension.sticky_ignore = e->sticky_ignore;
+ s->extension.stateless = e->stateless;
s->extension.use_server_error_pages = e->use_server_error_pages;
if (e->activation) {
s->extension.activation = apr_palloc(r->pool, e->activation_size *
sizeof(int));
@@ -817,6 +820,22 @@ static int init_ws_service(apache_privat
}
}
+ stateless = apr_table_get(r->subprocess_env, JK_ENV_STATELESS);
+ if (stateless) {
+ if (*stateless == '\0') {
+ s->extension.stateless = JK_TRUE;
+ }
+ else {
+ int r = atoi(stateless);
+ if (r) {
+ s->extension.stateless = JK_TRUE;
+ }
+ else {
+ s->extension.stateless = JK_FALSE;
+ }
+ }
+ }
+
if (conf->options & JK_OPT_DISABLEREUSE)
s->disable_reuse = 1;
Modified: tomcat/jk/trunk/native/common/jk_lb_worker.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/common/jk_lb_worker.c?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/common/jk_lb_worker.c (original)
+++ tomcat/jk/trunk/native/common/jk_lb_worker.c Thu Sep 22 23:23:18 2011
@@ -807,8 +807,9 @@ static int find_best_byvalue(jk_ws_servi
*/
if (JK_WORKER_USABLE(states[wr.i], activation)) {
if (candidate < 0 || wr.distance < d ||
- (wr.s->lb_value < curmin &&
- wr.distance == d)) {
+ (s->extension.stateless != JK_TRUE &&
+ wr.s->lb_value < curmin &&
+ wr.distance == d)) {
candidate = i;
curmin = wr.s->lb_value;
d = wr.distance;
@@ -1244,10 +1245,11 @@ static int JK_METHOD service(jk_endpoint
if (p->worker->lbmethod == JK_LB_METHOD_REQUESTS ||
p->worker->lbmethod == JK_LB_METHOD_BUSYNESS ||
(!sessionid &&
+ s->extension.stateless != JK_TRUE &&
(p->worker->lbmethod == JK_LB_METHOD_SESSIONS ||
p->worker->lbmethod == JK_LB_METHOD_NEXT)))
rec->s->lb_value += rec->lb_mult;
- if (!sessionid) {
+ if (!sessionid && s->extension.stateless != JK_TRUE) {
rec->s->sessions++;
}
if (p->worker->lblock == JK_LB_LOCK_PESSIMISTIC)
Modified: tomcat/jk/trunk/native/common/jk_service.h
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/common/jk_service.h?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/common/jk_service.h (original)
+++ tomcat/jk/trunk/native/common/jk_service.h Thu Sep 22 23:23:18 2011
@@ -84,6 +84,9 @@ struct svc_extension
int reply_timeout;
/* Whether to ignore session routing info */
int sticky_ignore;
+ /* Whether the request is stateless and should not
+ * influence session load balancing */
+ int stateless;
/* activation state overwrites for load balancers */
/* Dynamically allocated array with one entry per lb member. */
int *activation;
Modified: tomcat/jk/trunk/native/common/jk_status.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/common/jk_status.c?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/common/jk_status.c (original)
+++ tomcat/jk/trunk/native/common/jk_status.c Thu Sep 22 23:23:18 2011
@@ -1551,6 +1551,7 @@ static void display_map(jk_ws_service_t
uri_worker_map_get_source(uwr, l),
uwr->extensions.reply_timeout,
uwr->extensions.sticky_ignore,
+ uwr->extensions.stateless,
uwr->extensions.fail_on_status_str ?
uwr->extensions.fail_on_status_str : "-",
uwr->extensions.active ? uwr->extensions.active :
"-",
uwr->extensions.disabled ? uwr->extensions.disabled
: "-",
@@ -1563,6 +1564,7 @@ static void display_map(jk_ws_service_t
uri_worker_map_get_source(uwr, l),
uwr->extensions.reply_timeout,
uwr->extensions.sticky_ignore,
+ uwr->extensions.stateless,
uwr->extensions.fail_on_status_str ?
uwr->extensions.fail_on_status_str : "-",
uwr->extensions.active ? uwr->extensions.active :
"-",
uwr->extensions.disabled ? uwr->extensions.disabled
: "-",
@@ -1579,6 +1581,7 @@ static void display_map(jk_ws_service_t
jk_print_xml_att_string(s, 8, "source",
uri_worker_map_get_source(uwr, l));
jk_print_xml_att_int(s, 8, "reply_timeout",
uwr->extensions.reply_timeout);
jk_print_xml_att_int(s, 8, "sticky_ignore",
uwr->extensions.sticky_ignore);
+ jk_print_xml_att_int(s, 8, "stateless", uwr->extensions.stateless);
jk_print_xml_att_string(s, 8, "fail_on_status",
uwr->extensions.fail_on_status_str);
jk_print_xml_att_string(s, 8, "active", uwr->extensions.active);
jk_print_xml_att_string(s, 8, "disabled",
uwr->extensions.disabled);
@@ -1596,6 +1599,7 @@ static void display_map(jk_ws_service_t
jk_printf(s, " source=\"%s\"", uri_worker_map_get_source(uwr, l));
jk_printf(s, " reply_timeout=\"%d\"",
uwr->extensions.reply_timeout);
jk_printf(s, " sticky_ignore=\"%d\"",
uwr->extensions.sticky_ignore);
+ jk_printf(s, " stateless=\"%d\"", uwr->extensions.stateless);
jk_printf(s, " fail_on_status=\"%s\"",
uwr->extensions.fail_on_status_str ? uwr->extensions.fail_on_status_str : "");
jk_printf(s, " active=\"%s\"", uwr->extensions.active ?
uwr->extensions.active : "");
jk_printf(s, " disabled=\"%s\"", uwr->extensions.disabled ?
uwr->extensions.disabled : "");
@@ -1611,6 +1615,7 @@ static void display_map(jk_ws_service_t
jk_print_prop_item_string(s, w, worker, "map", count, "source",
uri_worker_map_get_source(uwr, l));
jk_print_prop_item_int(s, w, worker, "map", count,
"reply_timeout", uwr->extensions.reply_timeout);
jk_print_prop_item_int(s, w, worker, "map", count,
"sticky_ignore", uwr->extensions.sticky_ignore);
+ jk_print_prop_item_int(s, w, worker, "map", count, "stateless",
uwr->extensions.stateless);
jk_print_prop_item_string(s, w, worker, "map", count,
"fail_on_status", uwr->extensions.fail_on_status_str);
jk_print_prop_item_string(s, w, worker, "map", count, "active",
uwr->extensions.active);
jk_print_prop_item_string(s, w, worker, "map", count, "disabled",
uwr->extensions.disabled);
Modified: tomcat/jk/trunk/native/common/jk_uri_worker_map.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/common/jk_uri_worker_map.c?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/common/jk_uri_worker_map.c (original)
+++ tomcat/jk/trunk/native/common/jk_uri_worker_map.c Thu Sep 22 23:23:18 2011
@@ -41,6 +41,7 @@
#define JK_UWMAP_EXTENSION_REPLY_TIMEOUT "reply_timeout="
#define JK_UWMAP_EXTENSION_STICKY_IGNORE "sticky_ignore="
+#define JK_UWMAP_EXTENSION_STATELESS "stateless="
#define JK_UWMAP_EXTENSION_ACTIVE "active="
#define JK_UWMAP_EXTENSION_DISABLED "disabled="
#define JK_UWMAP_EXTENSION_STOPPED "stopped="
@@ -639,6 +640,7 @@ int uri_worker_map_add(jk_uri_worker_map
w = jk_pool_strdup(p, worker);
uwr->extensions.reply_timeout = -1;
uwr->extensions.sticky_ignore = JK_FALSE;
+ uwr->extensions.stateless = JK_FALSE;
uwr->extensions.active = NULL;
uwr->extensions.disabled = NULL;
uwr->extensions.stopped = NULL;
@@ -672,6 +674,15 @@ int uri_worker_map_add(jk_uri_worker_map
uwr->extensions.sticky_ignore = JK_FALSE;
}
}
+ else if (!strncmp(param, JK_UWMAP_EXTENSION_STATELESS,
strlen(JK_UWMAP_EXTENSION_STATELESS))) {
+ int val = atoi(param +
strlen(JK_UWMAP_EXTENSION_STATELESS));
+ if (val) {
+ uwr->extensions.stateless = JK_TRUE;
+ }
+ else {
+ uwr->extensions.stateless = JK_FALSE;
+ }
+ }
else if (!strncmp(param, JK_UWMAP_EXTENSION_USE_SRV_ERRORS,
strlen(JK_UWMAP_EXTENSION_USE_SRV_ERRORS))) {
uwr->extensions.use_server_error_pages = atoi(param +
strlen(JK_UWMAP_EXTENSION_USE_SRV_ERRORS));
}
Modified: tomcat/jk/trunk/native/common/jk_uri_worker_map.h
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/common/jk_uri_worker_map.h?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/common/jk_uri_worker_map.h (original)
+++ tomcat/jk/trunk/native/common/jk_uri_worker_map.h Thu Sep 22 23:23:18 2011
@@ -75,6 +75,9 @@ struct rule_extension
int reply_timeout;
/* Whether to ignore session routing info */
int sticky_ignore;
+ /* Whether the request is stateless and should not
+ * influence session load balancing */
+ int stateless;
/* activation state overwrites for load balancers */
/* Number of elements in the array activations. */
int activation_size;
Modified: tomcat/jk/trunk/native/common/jk_util.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/common/jk_util.c?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/common/jk_util.c (original)
+++ tomcat/jk/trunk/native/common/jk_util.c Thu Sep 22 23:23:18 2011
@@ -2076,6 +2076,7 @@ void jk_init_ws_service(jk_ws_service_t
s->flush_header = JK_FALSE;
s->extension.reply_timeout = -1;
s->extension.sticky_ignore = JK_FALSE;
+ s->extension.stateless = JK_FALSE;
s->extension.use_server_error_pages = 0;
s->extension.activation = NULL;
s->extension.fail_on_status_size = 0;
Modified: tomcat/jk/trunk/native/iis/jk_isapi_plugin.c
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/native/iis/jk_isapi_plugin.c?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/native/iis/jk_isapi_plugin.c (original)
+++ tomcat/jk/trunk/native/iis/jk_isapi_plugin.c Thu Sep 22 23:23:18 2011
@@ -3085,6 +3085,7 @@ static int init_ws_service(isapi_private
jk_log(logger, JK_LOG_DEBUG, "Applying service extensions" );
s->extension.reply_timeout = e->reply_timeout;
s->extension.sticky_ignore = e->sticky_ignore;
+ s->extension.stateless = e->stateless;
s->extension.use_server_error_pages = e->use_server_error_pages;
if (e->activation) {
s->extension.activation = jk_pool_alloc(s->pool,
e->activation_size * sizeof(int));
Modified: tomcat/jk/trunk/xdocs/miscellaneous/changelog.xml
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/xdocs/miscellaneous/changelog.xml?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/xdocs/miscellaneous/changelog.xml (original)
+++ tomcat/jk/trunk/xdocs/miscellaneous/changelog.xml Thu Sep 22 23:23:18 2011
@@ -62,6 +62,14 @@
It actually counts the number of requests that do not carry a session
id.
(rjung)
</add>
+ <add>
+ URI Map: Add "stateless" extension attributes to uri worker map.
+ This can improve session load balancing. (rjung)
+ </add>
+ <add>
+ HTTPD: Allow dynamic switching of requests to "stateless" using the
+ environment variable JK_STATELESS. (rjung)
+ </add>
</changelog>
</subsection>
</section>
Modified: tomcat/jk/trunk/xdocs/reference/apache.xml
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/xdocs/reference/apache.xml?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/xdocs/reference/apache.xml (original)
+++ tomcat/jk/trunk/xdocs/reference/apache.xml Thu Sep 22 23:23:18 2011
@@ -1124,7 +1124,7 @@ This is available since version 1.2.27.
</p>
<p>
The environment variable
-<b>JK_IGNORE_STICKY</b> can be set to disable session stickyness
+<b>JK_STICKY_IGNORE</b> can be set to disable session stickyness
for individual requests. If the variable is set to an empty string
or a nonzero number, session stickyness will be disabled. Setting
it to <b>0</b> will reset to the behaviour defined by the worker
@@ -1140,6 +1140,19 @@ the application which uses the session.
set this environment variable when a user requests a login form
to ensure, that this initial session request is balanced non-sticky.
</p>
+<p>
+The environment variable
+<b>JK_STATELESS</b> can be used to improve load balancing
+for the session based balancing methods <b>Session</b> and
+<b>Next</b>.
+In this case normally any request which does not come with
+a session id counts as a new session. This can be problematic,
+if for instance static content is retrieved without a session id.
+If you set the environment variable <b>JK_STATELESS</b> for a request,
+then the request will not count as a new session, even if it does not
+come with a session id.
+This is available since version 1.2.33.
+</p>
</subsection>
</section>
</body>
Modified: tomcat/jk/trunk/xdocs/reference/uriworkermap.xml
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/xdocs/reference/uriworkermap.xml?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/xdocs/reference/uriworkermap.xml (original)
+++ tomcat/jk/trunk/xdocs/reference/uriworkermap.xml Thu Sep 22 23:23:18 2011
@@ -249,7 +249,8 @@ For a general description of reply timeo
<subsection name="Extension sticky_ignore">
<br/>
<p>
-The extension <code>sticky_ignore</code> can disable session stickyness for a
single mapping rule.
+The extension <code>sticky_ignore</code> will disable session stickyness for a
single
+mapping rule.
<source>
# Disable session stickyness
# only for this mapping.
@@ -267,6 +268,22 @@ to ensure, that this initial session req
This extension is available since version 1.2.33.
</p>
</subsection>
+<subsection name="Extension stateless">
+<br/>
+<p>
+The extension <code>stateless</code> is only useful when using session based
+load balancing. In this case normally any request which does not come with
+a session id counts as a new session. If you mark a mapping rule with
+the <code>stateless</code> extension, then the requests matching the mapping
+rule will not count as a new session, even if they do not come with a session
+id.
+<source>
+ # Don't let static content trash our session balancing
+ /myapp/static/*=myworker;stateless=1
+</source>
+This extension is available since version 1.2.33.
+</p>
+</subsection>
<subsection name="Extensions active/disabled/stopped">
<br/>
<p>
Modified: tomcat/jk/trunk/xdocs/reference/workers.xml
URL:
http://svn.apache.org/viewvc/tomcat/jk/trunk/xdocs/reference/workers.xml?rev=1174449&r1=1174448&r2=1174449&view=diff
==============================================================================
--- tomcat/jk/trunk/xdocs/reference/workers.xml (original)
+++ tomcat/jk/trunk/xdocs/reference/workers.xml Thu Sep 22 23:23:18 2011
@@ -544,25 +544,26 @@ working well for most applications.
<p>
If method is set to <b>S[ession]</b> the balancer will use the number of
sessions
to find the best worker. Accesses will be distributed according to the
-lbfactor in a sliding time window. Because the balancer does not keep any
state,
+lbfactor in a sliding time window. This method should be used,
+if sessions are your limiting resource, e.g. when you only have limited memory
+and your sessions need a lot of memory. Because the balancer does not keep any
state,
it actually does not know the number of sessions. Instead it counts each
request
without a session cookie or URL encoding as a new session. This method will
neither
know, when a session is being invalidated, nor will it correct its load numbers
-according to session timeouts or worker failover. This method should be used,
-if sessions are your limiting resource, e.g. when you only have limited memory
-and your sessions need a lot of memory.
+according to session timeouts or worker failover. If you know request URLs,
that will be
+called without a session ID but should not be counted as new sessions, you
should
+add them to the <b>stateless</b> mapping rule extension or set the Apache HTTPD
+environment variable <b>JK_STATELESS</b> for them.
</p>
<p>
If method is set to <b>N[ext]</b> the balancer will again use the number of
sessions
-to find the best worker. The difference to the <b>S[ession]</b> method is how
-the session count is handled in the sliding time window. The <b>N[ext]</b>
method
-does not divide by 2, instead it subtracts the minimum number. This should
effectively
-result in a round-robin session balancing, thus the name <b>N[ext]</b>.
-Under high load, the two session balancing
-methods will result in a similar distribution, but <b>N[ext]</b> will be better
-if you need to distribute small numbers of sessions. Again this method will
-neither know, when a session is being invalidated, nor will it correct its
load numbers
-according to session timeouts or worker failover.
+to find the best worker. All remarks concerning the <b>Session</b>method apply
as well.
+The difference to the <b>Session</b> method is how the session count is
handled in the
+sliding time window. The <b>Next</b> method does not divide by 2, instead it
subtracts
+the current minimum number. This should effectively result in a round-robin
session
+balancing, thus the name <b>Next</b>. Under high load, the two session
balancing
+methods will result in a similar distribution, but <b>Next</b> will be better
+if you need to distribute small numbers of sessions.
</p>
<p>
If set to <b>T[raffic]</b> the balancer will use
@@ -580,8 +581,9 @@ interesting, if your request take a long
application.
</p>
<p>
-This feature has been added in <b>jk 1.2.9</b>.
-The Session method has been added in <b>jk 1.2.20</b>.
+This feature has been added in version <b>1.2.9</b>.
+The Session method has been added in version <b>1.2.20</b>,
+the <b>Next</b> method in version <b>1.2.32</b>..
</p>
</directive>
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