Out of memory Exception - On a node in cassandra cluster

["Tamil selvan R.S" <ta...@gmail.com>]

One of my cassandra nodes out of 4 nodes cluster gone down throwing this
exception out

ERROR [MutationStage:2405] 2011-11-24 14:44:46,242
AbstractCassandraDaemon.java (line 133) Fatal exception in thread
Thread[MutationStage:2405,5,main]
java.lang.OutOfMemoryError: unable to create new native thread
    at java.lang.Thread.start0(Native Method)
    at java.lang.Thread.start(Thread.java:691)
    at
java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:943)
    at
java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1325)
    at
org.apache.cassandra.service.StorageProxy$6.runMayThrow(StorageProxy.java:561)
    at
org.apache.cassandra.service.StorageProxy$DroppableRunnable.run(StorageProxy.java:1254)
    at
java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1110)
    at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:603)
    at java.lang.Thread.run(Thread.java:722)
ERROR [Thread-19] 2011-11-24 14:44:46,245 AbstractCassandraDaemon.java
(line 133) Fatal exception in thread Thread[Thread-19,5,main]
java.lang.OutOfMemoryError: unable to create new native thread
    at java.lang.Thread.start0(Native Method)
    at java.lang.Thread.start(Thread.java:691)
    at
java.util.concurrent.ThreadPoolExecutor.addWorker(ThreadPoolExecutor.java:943)
    at
java.util.concurrent.ThreadPoolExecutor.execute(ThreadPoolExecutor.java:1325)
    at
org.apache.cassandra.net.MessagingService.receive(MessagingService.java:521)
    at
org.apache.cassandra.net.IncomingTcpConnection.receiveMessage(IncomingTcpConnection.java:159)
    at
org.apache.cassandra.net.IncomingTcpConnection.run(IncomingTcpConnection.java:117)

Wish to have some help over this.

Cassandra version - 1.0.2 RPM built on Red Hat 6
Memory allocated to Cassandra - 8 GB

Regards,
Tamil