Can you please provide more information about how you producing this
behavior. What specific commands are you executing, starting from a
fresh install? Are you enabling monitoring? Are the instances in a
cluster? Have applications been deployed? Are the instances on different
servers?
I started with a fresh install. The DAS had 50 threads (based on jstack
output). After creating the first instance, the number of threads went
up to 65 (which is expected as the first asadmin command that is
executed will do this).Then I created 19 more instances using
create-local-instance and the number of threads in the DAS was 67.
Then I started 10 of the instances and the number of DAS threads was
down to 56. After enabling monitoring on all of the instances, the
number of threads went up to 72 but later went back down to 67.
Note: these were all stand-alone instances, not clustered instances and
everything was on one system.
If 4 threads were created for every instance, I would expect to see
either 80 (based on the number created) or 40 (based on the number
started) additional threads, but I'm not seeing that.
Tom
On 3/8/2011 6:14 AM, glassfish.lu wrote:
> Hi, All:
> I find the number of the active threads in GlassFish DAS will increase
> greatly as new server instance is created.
> such as:
> *For each server instance, a {ClientNotifForwarder} thread will be
> created.*
>
> "ClientNotifForwarder-20" daemon prio=1 tid=0x0000000050b108e0
> nid=0x6f27 runnable [0x00000000560af000..0x00000000560afb10]
> at java.net.SocketInputStream.socketRead0(Native Method)
> at java.net.SocketInputStream.read(SocketInputStream.java:129)
> at java.io.BufferedInputStream.fill(BufferedInputStream.java:218)
> at java.io.BufferedInputStream.read(BufferedInputStream.java:235)
> - locked <0x00002ab056932048> (a java.io.BufferedInputStream)
> at java.io.DataInputStream.readByte(DataInputStream.java:241)
> at
> sun.rmi.transport.StreamRemoteCall.executeCall(StreamRemoteCall.java:189)
> at sun.rmi.server.UnicastRef.invoke(UnicastRef.java:126)
> at com.sun.jmx.remote.internal.PRef.invoke(Unknown Source)
> at
> javax.management.remote.rmi.RMIConnectionImpl_Stub.fetchNotifications(Unknown
> Source)
> at
> javax.management.remote.rmi.RMIConnector$RMINotifClient.fetchNotifs(RMIConnector.java:1285)
> at
> com.sun.jmx.remote.internal.ClientNotifForwarder$NotifFetcher.fetchNotifs(ClientNotifForwarder.java:559)
> at
> com.sun.jmx.remote.internal.ClientNotifForwarder$NotifFetcher.doRun(ClientNotifForwarder.java:441)
> at
> com.sun.jmx.remote.internal.ClientNotifForwarder$NotifFetcher.run(ClientNotifForwarder.java:422)
> at
> com.sun.jmx.remote.internal.ClientNotifForwarder$LinearExecutor$1.run(ClientNotifForwarder.java:88)
>
> *For each server instance, a {*JMX server connection timeout}*thread
> will be created.*
>
> "JMX server connection timeout 463" daemon prio=1
> tid=0x0000000050963310 nid=0x6f1e in Object.wait()
> [0x0000000055baa000..0x0000000055baac90]
> at java.lang.Object.wait(Native Method)
> - waiting on <0x00002ab056201dc0> (a [I)
> at
> com.sun.jmx.remote.internal.ServerCommunicatorAdmin$Timeout.run(ServerCommunicatorAdmin.java:150)
> - locked <0x00002ab056201dc0> (a [I)
> at java.lang.Thread.run(Thread.java:595)
>
> *For each server instance, a {*RMI RenewClean }*thread will be
> created.*
>
> "RMI RenewClean-[192.168.2.151:33057]" daemon prio=1
> tid=0x0000000051370380 nid=0x6e94 in Object.wait()
> [0x0000000054796000..0x0000000054796c90]
> at java.lang.Object.wait(Native Method)
> - waiting on <0x00002ab03c1d8730> (a
> java.lang.ref.ReferenceQueue$Lock)
> at java.lang.ref.ReferenceQueue.remove(ReferenceQueue.java:120)
> - locked <0x00002ab03c1d8730> (a
> java.lang.ref.ReferenceQueue$Lock)
> at
> sun.rmi.transport.DGCClient$EndpointEntry$RenewCleanThread.run(DGCClient.java:501)
> at java.lang.Thread.run(Thread.java:595)
>
> *And some {RMI ConnectionExpiration} thread will also be created.*
>
> "RMI ConnectionExpiration-[192.168.2.151:41022]" daemon prio=1
> tid=0x00000000514ecbb0 nid=0x73b6 waiting on condition
> [0x000000004d5cd000..0x000000004d5cdb10]
> at java.lang.Thread.sleep(Native Method)
> at
> sun.rmi.transport.tcp.TCPChannel$Reaper.run(TCPChannel.java:446)
> at java.lang.Thread.run(Thread.java:595)
>
> As the number of instances managed by DAS grow, the thread created
> by JVM will grow accordingly .
> Sometimes the number will exceed the thread limit of JVM.
> So my question now is how to avoid this situation, how to reduce
> these threads.
> Is there any system property configuration or configuration in
> domain.xml to workaroud this.
> Thanks guys in advance.
>
> Best Regards.
>