I am experiencing an issue with Exchange 2013 CU2 DAG, Exchange Mailbox VM are experiencing unexpected issues.

Recently I have noticed the events logs logged under one of the VM under System Logs as follows. Similar logs are logging in second Mailbox VMs as well.

1.      A process serving application pool 'MSExchangePowerShellFrontEndAppPool' failed to respond to a ping. The process id was '14112'. Log Name: System, Source: WAS, Event ID 5010. Log time 19-09-201303:15:26

2.      A process serving application pool 'MSExchangeServicesAppPool' failed to respond to a ping. The process id was '8468'. Log Name: System, Source: WAS, Event ID 5010. Log time 19-09-201303:15:39

3.      A process serving application pool 'MSExchangeECPAppPool' failed to respond to a ping. The process id was '13476'. Log Name: System, Source: WAS, Event ID 5010. Log time 19-09-201303:15:51

4.      A process serving application pool 'MSExchangeSyncAppPool' failed to respond to a ping. The process id was '15712'. Log Name: System, Source: WAS, Event ID 5010. Log time 19-09-201303:15:53

5.      A timeout (30000 milliseconds) was reached while waiting for a transaction response from the HostControllerService service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:16:23

6.      A process serving application pool 'MSExchangeOWAAppPool' failed to respond to a ping. The process id was '15632'. Log Name: System, Source: WAS, Event ID 5010. Log time 19-09-201303:17:29

7.      The Application Experience service entered the stopped state. Log Name: System, Source: Service Control Manager, Event ID 7036. Log time 19-09-201303:17:46

8.      A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeDagMgmt service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:18:13

9.      A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeDagMgmt service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:18:43

10.  A process serving application pool 'MSExchangeAutodiscoverAppPool' failed to respond to a ping. The process id was '12824'. Log Name: System, Source: WAS, Event ID 5010. Log time 19-09-201303:20:32

11.  A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeDelivery service. . Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:19:18

12.  A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeMailboxAssistants service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:19:50

13.  A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeFastSearch service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:20:00

14.  A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeMailboxReplication service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:20:21

15.  A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeMailboxAssistants service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:20:38

16.  A timeout (30000 milliseconds) was reached while waiting for a transaction response from the MSExchangeMailboxReplication service. Log Name: System, Source: Service Control Manager, Event ID 7011. Log time 19-09-201303:21:09

17.  A process serving application pool 'MSExchangeECPAppPool' suffered a fatal communication error with the Windows Process Activation Service. The process id was '11608'. The data field contains the error number. Log Name: System, Source: WAS, Event ID 5011. Log time 19-09-2013 03:21:58

18.  A process serving application pool 'MSExchangeServicesAppPool' failed to respond to a ping. The process id was '12724'. Log Name: System, Source: WAS, Event ID 5010. Log time 19-09-201303:23:20

19.  The Microsoft Exchange Service Host service terminated unexpectedly. It has done this 1 time(s).  The following corrective action will be taken in 5000 milliseconds: Restart the service. Log Name: System, Source: Service Control Manager, Event ID 7031. Log time 19-09-201303:24:25

20.  The Microsoft Exchange DAG Management service terminated unexpectedly. It has done this 1 time(s).  The following corrective action will be taken in 5000 milliseconds: Restart the service. Log Name: System, Source: Service Control Manager, Event ID 7031. Log time 19-09-201303:37:07

21.  Cluster node 'BESTECH-MB02' was removed from the active failover cluster membership. The Cluster service on this node may have stopped. This could also be due to the node having lost communication with other active nodes in the failover cluster. Run the Validate a Configuration wizard to check your network configuration. If the condition persists, check for hardware or software errors related to the network adapters on this node. Also check for failures in any other network components to which the node is connected such as hubs, switches, or bridges. Log Name: System, Source: FailoverClustering, Event ID 1135. Log time 19-09-201304:20:37

22.  DCOM was unable to communicate with the computer BESTECH-MB02.bestech.com using any of the configured protocols; requested by PID    2808 (C:\Windows\system32\ServerManager.exe). Log Name: System, Source: DistributedCOM, Event ID 10028. Log time 19-09-201304:21:33

23.  DCOM was unable to communicate with the computer BESTECH-MB02.bestech.com using any of the configured protocols; requested by PID    3834 (E:\Program Files\Microsoft\Exchange Server\V15\Bin\MSExchangeHMWorker.exe). Log Name: System, Source: DistributedCOM, Event ID 10028. Log time 19-09-201304:32:02

I want to also enable Level 5 Logging for cluster log, may be cluster log will give us some clue to go to root of the issue....