Displaying Host details for active Proxy Connections

Question

It is possible via JMX to display the number of active connections associated with Proxy services.
For problem resolution it would be very useful to determine the hosts that are connected. I already have a mechanism of capturing new connection requests (for logical connection throttling) so I can log the host details when a new connection is used - but my preference would be to view this in realtime e.g. via JMX. (Similar in concept to viewing all JMS clients that are connected to a JMS server).
Q1. Is there a way the above can be achieved and/or is there any intention to move this feature in to the core product?
Q2. If my client VM that has an open connection dies unexpectedly how quickly will the Proxy service recycle the connection and decrement the active connection count?
Thanks,
Simon

Answer 1

Q1: It is our policy to not comment on contents/dates of future releases in the forum. However, Oracle is always looking to improve the usability and manageability of Coherence. To help me advocate this feature, could you elaborate on the information being collected, the usage models and the value proposition.
To help with the short term issue, The information you currently logging can be exposed through JMX by creating a custom MBean. The custom MBean is a combination of an Interface and an Implementation.
To create a custom MBean "ConnectionCounter":
Define the interface:
Interface ConnectionCounterMBean
public int getConnectionCount();
public class ConnectionCounter
implements ConnectionCounterMBean
public int getConnectionCount()
// return the connection count.
Register the custom MBean:
http://wiki.tangosol.com/display/COH33UG/Manage+Custom+MBeans+within+the+Coherence+Cluster
Q2: A Coherence*Extend service has several mechanisms for detecting dropped connections. Some mechanisms are inherent to the underlying protocol (i.e. a javax.jms.ExceptionListener in Extend-JMS and TCP/IP in Extend-TCP), whereas others are implemented by the service itself. The latter mechanisms are configured via the <outgoing-message-handler> configuration element.
The primary configurable mechanism used by a Coherence*Extend client service to detect dropped connections is a request timeout. When the service sends a request to the remote cluster and does not receive a response within the request timeout interval (see <request-timeout>), the service assumes that the connection has been dropped. The Coherence*Extend client and clustered services can also be configured to send a periodic heartbeat over the connection (see <heartbeat-interval> and <heartbeat-timeout>). If the service does not receive a response within the configured heartbeat timeout interval, the service assumes that the connection has been dropped.
For more information:
http://wiki.tangosol.com/display/COH33UG/Configuring+and+Using+Coherence*Extend
Hope this helps,
Everett Williams
Coherence development team