From ecabde4c14663c3c26e29fcdba4276e9407b3915 Mon Sep 17 00:00:00 2001 From: "emellor@leeni.uk.xensource.com" Date: Fri, 3 Mar 2006 15:41:56 +0100 Subject: [PATCH] Change the way that reboot-timeouts are handled. Rather than refreshing the list of domains each time XendDomainInfo.refresh is called, and spawning threads for each shutdown still in progress, we watch the control/shutdown node and spawn just the one thread immediately. When the daemon starts (say after a crash) all domains are checked for entries in the store indicating a reboot in progress. This avoids a large cost on the store and in threads when the list of domains is refreshed. This happens every time the server is queried, so the cost can be quite high. It's especially a high cost when using xm shutdown -a -w -- this operation should perform a lot better now. Signed-off-by: Ewan Mellor --- tools/python/xen/xend/XendDomainInfo.py | 81 ++++++++++++++++++------- 1 file changed, 59 insertions(+), 22 deletions(-) diff --git a/tools/python/xen/xend/XendDomainInfo.py b/tools/python/xen/xend/XendDomainInfo.py index 9007a2ce49..608604cc4a 100644 --- a/tools/python/xen/xend/XendDomainInfo.py +++ b/tools/python/xen/xend/XendDomainInfo.py @@ -13,7 +13,7 @@ # Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA #============================================================================ # Copyright (C) 2004, 2005 Mike Wray -# Copyright (C) 2005 XenSource Ltd +# Copyright (C) 2005, 2006 XenSource Ltd #============================================================================ """Representation of a single domain. @@ -82,7 +82,7 @@ restart_modes = [ STATE_DOM_OK = 1 STATE_DOM_SHUTDOWN = 2 -SHUTDOWN_TIMEOUT = 30 +SHUTDOWN_TIMEOUT = 30.0 ZOMBIE_PREFIX = 'Zombie-' @@ -182,7 +182,7 @@ def create(config): vm.initDomain() vm.storeVmDetails() vm.storeDomDetails() - vm.registerWatch() + vm.registerWatches() vm.refreshShutdown() return vm except: @@ -238,7 +238,7 @@ def recreate(xeninfo, priv): vm.storeVmDetails() vm.storeDomDetails() - vm.registerWatch() + vm.registerWatches() vm.refreshShutdown(xeninfo) return vm @@ -443,7 +443,10 @@ class XendDomainInfo: self.console_mfn = None self.vmWatch = None + self.shutdownWatch = None + self.shutdownStartTime = None + self.state = STATE_DOM_OK self.state_updated = threading.Condition() self.refresh_shutdown_lock = threading.Condition() @@ -648,7 +651,7 @@ class XendDomainInfo: self.introduceDomain() self.storeDomDetails() - self.registerWatch() + self.registerWatches() self.refreshShutdown() log.debug("XendDomainInfo.completeRestore done") @@ -711,13 +714,15 @@ class XendDomainInfo: ## public: - def registerWatch(self): - """Register a watch on this VM's entries in the store, so that - when they are changed externally, we keep up to date. This should - only be called by {@link #create}, {@link #recreate}, or {@link - #restore}, once the domain's details have been written, but before the - new instance is returned.""" + def registerWatches(self): + """Register a watch on this VM's entries in the store, and the + domain's control/shutdown node, so that when they are changed + externally, we keep up to date. This should only be called by {@link + #create}, {@link #recreate}, or {@link #restore}, once the domain's + details have been written, but before the new instance is returned.""" self.vmWatch = xswatch(self.vmpath, self.storeChanged) + self.shutdownWatch = xswatch(self.dompath + '/control/shutdown', + self.handleShutdownWatch) def getDomid(self): @@ -852,20 +857,14 @@ class XendDomainInfo: # Domain is alive. If we are shutting it down, then check # the timeout on that, and destroy it if necessary. - sst = self.readDom('xend/shutdown_start_time') - if sst: - sst = float(sst) - timeout = SHUTDOWN_TIMEOUT - time.time() + sst + if self.shutdownStartTime: + timeout = (SHUTDOWN_TIMEOUT - time.time() + + self.shutdownStartTime) if timeout < 0: log.info( "Domain shutdown timeout expired: name=%s id=%s", self.info['name'], self.domid) self.destroy() - else: - log.debug( - "Scheduling refreshShutdown on domain %d in %ds.", - self.domid, timeout) - threading.Timer(timeout, self.refreshShutdown).start() finally: self.refresh_shutdown_lock.release() @@ -873,12 +872,34 @@ class XendDomainInfo: self.maybeRestart(restart_reason) + def handleShutdownWatch(self, _): + log.debug('XendDomainInfo.handleShutdownWatch') + + reason = self.readDom('control/shutdown') + + if reason and reason != 'suspend': + sst = self.readDom('xend/shutdown_start_time') + now = time.time() + if sst: + self.shutdownStartTime = float(sst) + timeout = float(sst) + SHUTDOWN_TIMEOUT - now + else: + self.shutdownStartTime = now + self.storeDom('xend/shutdown_start_time', now) + timeout = SHUTDOWN_TIMEOUT + + log.trace( + "Scheduling refreshShutdown on domain %d in %ds.", + self.domid, timeout) + threading.Timer(timeout, self.refreshShutdown).start() + + return 1 + + def shutdown(self, reason): if not reason in shutdown_reasons.values(): raise XendError('Invalid reason: %s' % reason) self.storeDom("control/shutdown", reason) - if reason != 'suspend': - self.storeDom('xend/shutdown_start_time', time.time()) ## private: @@ -1225,6 +1246,8 @@ class XendDomainInfo: """Cleanup domain resources; release devices. Idempotent. Nothrow guarantee.""" + self.unwatchShutdown() + self.release_devices() if self.image: @@ -1276,6 +1299,20 @@ class XendDomainInfo: log.exception("Unwatching VM path failed.") + def unwatchShutdown(self): + """Remove the watch on the domain's control/shutdown node, if any. + Idempotent. Nothrow guarantee.""" + + try: + try: + if self.shutdownWatch: + self.shutdownWatch.unwatch() + finally: + self.shutdownWatch = None + except: + log.exception("Unwatching control/shutdown failed.") + + ## public: def destroy(self): -- 2.30.2