If the agent is not responding correctly to requests, it's possible for agent connections from the server to hang forever. This is common when doing mass operations where many agents need to be contacted, such as changing metric templates globally.

Need to investigate if setting a connection timeout would solve this problem.

The full thread dump:

"http-0.0.0.0-7080-177" daemon prio=10 tid=0x00002aab782abc00 nid=0x4274 runnable [0x000000005afcc000..0x000000005afd6c20]
   java.lang.Thread.State: RUNNABLE
        at java.net.SocketInputStream.socketRead0(Native Method)
        at java.net.SocketInputStream.read(SocketInputStream.java:129)
        at com.sun.net.ssl.internal.ssl.InputRecord.readFully(InputRecord.java:293)
        at com.sun.net.ssl.internal.ssl.InputRecord.read(InputRecord.java:331)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.readRecord(SSLSocketImpl.java:789)
        - locked <0x00002aaaefef7a80> (a java.lang.Object)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.performInitialHandshake(SSLSocketImpl.java:1096)
        - locked <0x00002aaaefef7a28> (a java.lang.Object)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1123)
        at com.sun.net.ssl.internal.ssl.SSLSocketImpl.startHandshake(SSLSocketImpl.java:1107)
        at org.hyperic.hq.bizapp.agent.client.SecureAgentConnection.getSSLSocket(SecureAgentConnection.java:95)
        at org.hyperic.hq.bizapp.agent.client.SecureAgentConnection.getSocket(SecureAgentConnection.java:132)
        at org.hyperic.hq.agent.client.AgentConnection.sendCommandHeaders(AgentConnection.java:153)
        at org.hyperic.hq.agent.client.AgentConnection.sendCommand(AgentConnection.java:121)
        at org.hyperic.hq.measurement.agent.client.MeasurementCommandsClient.getMeasurements(MeasurementCommandsClient.java:135)
        at org.hyperic.hq.measurement.agent.client.AgentMonitor.getLiveValues(AgentMonitor.java:218)