Tell Tomcat to drop requests instead of dying "All threads (150) are currently busy"
- by Nicolas Raoul
My Tomcat 6.0.26 sometimes dies saying:
SEVERE: All threads (150) are currently busy, waiting. Increase
maxThreads (150) or check the servlet status
... then Tomcat shuts down, and users can't access the webapp until I restart Tomcat manually.
Some of the threads indeed take a long time to execute, it is by-design, not a thread-gone-wild problem.
I know I could increase maxThreads, but that is not a viable solution, because the server might receive requests even more requests.
QUESTION: Instead of dying, can I tell Tomcat to just drop requests when maxThreads is reached and the AJP/1.3 backlog is full?
Below is my server.xml in any case:
<?xml version='1.0' encoding='utf-8'?>
<Server port="8005" shutdown="SHUTDOWN">
<Listener className="org.apache.catalina.core.AprLifecycleListener" SSLEngine="on" />
<Listener className="org.apache.catalina.core.JasperListener" />
<Listener className="org.apache.catalina.mbeans.ServerLifecycleListener" />
<Listener className="org.apache.catalina.mbeans.GlobalResourcesLifecycleListener" />
<GlobalNamingResources>
<Resource name="UserDatabase" auth="Container"
type="org.apache.catalina.UserDatabase"
description="User database that can be updated and saved"
factory="org.apache.catalina.users.MemoryUserDatabaseFactory"
pathname="conf/tomcat-users.xml" />
</GlobalNamingResources>
<Service name="Catalina">
<Executor name="tomcatThreadPool" namePrefix="catalina-exec-" minSpareThreads="100"/>
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443" />
<Connector port="8009" protocol="AJP/1.3" redirectPort="8443"
enableLookups="false" useBodyEncodingForURI="true"
backlog="150" maxThreads="150" executor="tomcatThreadPool"
keepAliveTimeout="5000" connectionTimeout="300000" />
<Engine name="Catalina" defaultHost="localhost" jvmRoute="ecm1">
<Realm className="org.apache.catalina.realm.UserDatabaseRealm"
resourceName="UserDatabase"/>
<Host name="localhost" appBase="webapps"
unpackWARs="true" autoDeploy="true"
xmlValidation="false" xmlNamespaceAware="false">
</Host>
</Engine>
</Service>
</Server>
