I agree with Mario. It really seams llike the internal structure of the TreeMap is destroyed, thus ending in some infinite loop and causing 100% CPU.
Shouldn't we generally synchronize those Maps or use ConcurrentMaps? Regards, Jakob Korherr 2009/12/10 Mario Ivankovits <ma...@ops.co.at> > For me, this clearly looks like concurrent usage of the request map. > > All the servlet scopes (session, request, …) are not thread safe and one > has to assure that they are not accessed at the same time by multiple > threads. > > > > This turns out to be hard as e.g. there is no "standard" how to synchronize > against the session map. As a side note: I often wonder why this does not > lead to much more problems in the wild … > > > > Anyway, in your case it seems the internal datastructure of the request map > is damaged - which in fact is strange as I do not know when the request map > will be accessed by multiple threads. > > > > Sorry that this is not a solution, but it should give you a clue where to > look next … > > > > Ciao, > > Mario > > > > *Von:* Jan Baudisch [mailto:jan.baudi...@gmx.net] > *Gesendet:* Donnerstag, 10. Dezember 2009 08:02 > *An:* MyFaces Discussion > *Betreff:* 100% CPU Usage and blocking concurrent Threads when using > t:saveState > > > > Hello MyFaces Community, > > > > we are using MyFaces 1.2.0 with Tomahawk Sandbox 1.1.5 and have the > problem, that once in a while we get 100% CPU Usage and blocking concurrent > threads because of using t:saveState > > > > A thread dump shows that the threads always stops at > > > > at java.util.TreeMap.put(TreeMap.java:545) > > at > org.apache.myfaces.custom.redirectTracker.RedirectTrackerManager.addSaveStateBean(RedirectTrackerManager.java:306) > > at > org.apache.myfaces.custom.redirectTracker.RedirectTrackerVariableResolver.resolveVariable(RedirectTrackerVariableResolver.java:50) > > > > (The complete thread dump is attached). The problem shows up on one system > with heavy concurrent usage and JxBrowser as client. > > > > After we kill these threads using Lambda Probe, the CPU Usage normalizes. > > > > The problem occurs in that method: > > > > ... > > public void addSaveStateBean(String expressionString, Object value) > > { > > if(log.isDebugEnabled()) > > log.debug("addSaveStateBean: " + expressionString + " value=" + > value); > > requestBeanMap.put(expressionString, value); > > } > > ... > > private final Map requestBeanMap = new TreeMap(); ... > > > > As the problem is really severe for us, any hints are highly appreciated. > > > > Many thanks in advance, > > -- Jan > > >
