File 10859.patch of Package squid-beta
---------------------
PatchSet 10859
Date: 2007/06/19 21:13:49
Author: rousskov
Branch: HEAD
Tag: (none)
Log:
Partial bug #1973 fix: Try to revive a suspended service after the
icap_service_revival_delay.
When a service gets suspended, schedule an OPTIONS update after the
icap_service_revival_delay. If there is already an OPTIONS fetch scheduled,
that outdated event will be deleted using eventDelete().
Eventually, we may want to have a separate option to control suspended
service revival.
Polished code, comments, and debugging.
Merged from the squid3-icap branch.
Members:
src/ICAP/ICAPServiceRep.cc:1.15->1.16
src/ICAP/ICAPServiceRep.h:1.9->1.10
Index: squid3/src/ICAP/ICAPServiceRep.cc
===================================================================
RCS file: /cvsroot/squid/squid3/src/ICAP/ICAPServiceRep.cc,v
retrieving revision 1.15
retrieving revision 1.16
diff -u -r1.15 -r1.16
--- squid3/src/ICAP/ICAPServiceRep.cc 30 May 2007 20:22:30 -0000 1.15
+++ squid3/src/ICAP/ICAPServiceRep.cc 19 Jun 2007 21:13:49 -0000 1.16
@@ -175,8 +175,11 @@
void ICAPServiceRep::noteFailure() {
++theSessionFailures;
- debugs(93,4, "ICAPService failure " << theSessionFailures <<
- ", out of " << TheICAPConfig.service_failure_limit << " allowed");
+ debugs(93,4, theSessionFailures << " ICAPService failures, out of " <<
+ TheICAPConfig.service_failure_limit << " allowed " << status());
+
+ if (isSuspended)
+ return;
if (TheICAPConfig.service_failure_limit >= 0 &&
theSessionFailures > TheICAPConfig.service_failure_limit)
@@ -194,6 +197,7 @@
} else {
isSuspended = reason;
debugs(93,1, "suspending ICAPService for " << reason);
+ scheduleUpdate(squid_curtime + TheICAPConfig.service_revival_delay);
announceStatusChange("suspended", true);
}
}
@@ -453,7 +457,7 @@
debugs(93,3, "ICAPService got new options and is now " << status());
- scheduleUpdate();
+ scheduleUpdate(optionsFetchTime());
scheduleNotification();
}
@@ -468,53 +472,67 @@
// Such a timeout should probably be a generic AsyncStart feature.
}
-void ICAPServiceRep::scheduleUpdate()
+void ICAPServiceRep::scheduleUpdate(time_t when)
{
- if (updateScheduled)
- return; // already scheduled
-
- // XXX: move hard-coded constants from here to TheICAPConfig
-
- // conservative estimate of how long the OPTIONS transaction will take
- const int expectedWait = 20; // seconds
-
- time_t when = 0;
-
- if (theOptions && theOptions->valid()) {
- const time_t expire = theOptions->expire();
- debugs(93,7, "ICAPService options expire on " << expire << " >= " << squid_curtime);
-
- // Unknown or invalid (too small) expiration times should not happen.
- // ICAPOptions should use the default TTL, and ICAP servers should not
- // send invalid TTLs, but bugs and attacks happen.
- if (expire < expectedWait)
- when = squid_curtime + 60*60;
+ if (updateScheduled) {
+ debugs(93,7, "ICAPService reschedules update");
+ // XXX: check whether the event is there because AR saw
+ // an unreproducible eventDelete assertion on 2007/06/18
+ if (eventFind(&ICAPServiceRep_noteTimeToUpdate, this))
+ eventDelete(&ICAPServiceRep_noteTimeToUpdate, this);
else
- when = expire - expectedWait; // before the current options expire
- } else {
- // delay for a down service
- when = squid_curtime + TheICAPConfig.service_revival_delay;
+ debugs(93,1, "XXX: ICAPService lost an update event.");
+ updateScheduled = false;
}
- debugs(93,7, "ICAPService options raw update at " << when << " or in " <<
+ debugs(93,7, HERE << "raw OPTIONS fetch at " << when << " or in " <<
(when - squid_curtime) << " sec");
+ debugs(93,9, HERE << "last fetched at " << theLastUpdate << " or " <<
+ (squid_curtime - theLastUpdate) << " sec ago");
/* adjust update time to prevent too-frequent updates */
if (when < squid_curtime)
when = squid_curtime;
- const int minUpdateGap = expectedWait + 10; // seconds
+ // XXX: move hard-coded constants from here to TheICAPConfig
+ const int minUpdateGap = 30; // seconds
if (when < theLastUpdate + minUpdateGap)
when = theLastUpdate + minUpdateGap;
const int delay = when - squid_curtime;
- debugs(93,5, "ICAPService will update options in " << delay << " sec");
+ debugs(93,5, "ICAPService will fetch OPTIONS in " << delay << " sec");
+
eventAdd("ICAPServiceRep::noteTimeToUpdate",
&ICAPServiceRep_noteTimeToUpdate, this, delay, 0, true);
updateScheduled = true;
}
+// returns absolute time when OPTIONS should be fetched
+time_t
+ICAPServiceRep::optionsFetchTime() const
+{
+ if (theOptions && theOptions->valid()) {
+ const time_t expire = theOptions->expire();
+ debugs(93,7, "ICAPService options expire on " << expire << " >= " << squid_curtime);
+
+ // conservative estimate of how long the OPTIONS transaction will take
+ // XXX: move hard-coded constants from here to TheICAPConfig
+ const int expectedWait = 20; // seconds
+
+ // Unknown or invalid (too small) expiration times should not happen.
+ // ICAPOptions should use the default TTL, and ICAP servers should not
+ // send invalid TTLs, but bugs and attacks happen.
+ if (expire < expectedWait)
+ return squid_curtime;
+ else
+ return expire - expectedWait; // before the current options expire
+ }
+
+ // use revival delay as "expiration" time for a service w/o valid options
+ return squid_curtime + TheICAPConfig.service_revival_delay;
+}
+
// returns a temporary string depicting service status, for debugging
const char *ICAPServiceRep::status() const
{
Index: squid3/src/ICAP/ICAPServiceRep.h
===================================================================
RCS file: /cvsroot/squid/squid3/src/ICAP/ICAPServiceRep.h,v
retrieving revision 1.9
retrieving revision 1.10
diff -u -r1.9 -r1.10
--- squid3/src/ICAP/ICAPServiceRep.h 29 May 2007 13:31:44 -0000 1.9
+++ squid3/src/ICAP/ICAPServiceRep.h 19 Jun 2007 21:13:49 -0000 1.10
@@ -1,6 +1,6 @@
/*
- * $Id: ICAPServiceRep.h,v 1.9 2007/05/29 13:31:44 amosjeffries Exp $
+ * $Id: ICAPServiceRep.h,v 1.10 2007/06/19 21:13:49 rousskov Exp $
*
*
* SQUID Web Proxy Cache http://www.squid-cache.org/
@@ -47,10 +47,13 @@
host many ICAP services. */
/*
- * A service is "up" if there is a fresh cached OPTIONS response and is
- * "down" otherwise. A service is "probed" if we tried to get an OPTIONS
- * response from it and succeeded or failed. A probed down service is
- * called "broken".
+ * A service with a fresh cached OPTIONS response and without many failures
+ * is an "up" service. All other services are "down". A service is "probed"
+ * if we tried to get an OPTIONS response from it and succeeded or failed.
+ * A probed down service is called "broken".
+ *
+ * The number of failures required to bring an up service down is determined
+ * by icap_service_failure_limit in squid.conf.
*
* As a bootstrapping mechanism, ICAP transactions wait for an unprobed
* service to get a fresh OPTIONS response (see the callWhenReady method).
@@ -151,8 +154,9 @@
bool hasOptions() const;
bool needNewOptions() const;
+ time_t optionsFetchTime() const;
- void scheduleUpdate();
+ void scheduleUpdate(time_t when);
void scheduleNotification();
void startGettingOptions();
