[SNMP4J] problem receiving v3Traps over TCP using DefaultTcpTransportMapping

[shanmugam vairavan]

Hi,



I am using snmp4j (v1.9.2) for writing a V3Trap listener. The listener
should be able to receive 'hundreds of thousands' of V3Traps per day, over
TCP from multiple senders. When testing my listener implementation I found
that my listener goes into a deadlock, and stops listening when the load
increases (say 2 senders, sending Traps of size 500kilobytes per
10milliseconds). The listener is running on a machine with the following
configuration: Intel Pentium (D) CPU 3.40GHz, Windows XP Professional SP3,
2GB RAM, 100Mbps LAN.



When the problem occurred, TCPView shows around 40 TCP connections (for my
listener port) with almost all in ESTABLISHED state, barring a few in
CLOSE_WAIT state. I have attached the same.



Debug reveled the reason for this problem being the
java.nio.channels.Selector.select() call in
DefaultTcpTransportMapping$ServerThread.run() method blocks forever. I even
tried modifying the call with a timeout,
java.nio.channels.Selector.select(10000). Now there is no deadlock but when
the load increases the call always returns 0.



Has anyone faced a similar situation before? Is this problem inherent to TCP
or the Sun's NIO implementation? Please provide me some pointers to solve
the same.



PS: Please let me know if you need any further information regarding my
setup and code.



Thanks & Regards

Shanmugam.VE