You can use the Distribution and Consistency Services (DCS) counters that the Performance Monitoring Infrastructure (PMI) and Tivoli Performance Viewer (TPV) collect to monitor communication between core groups.
| Name | Key | Description | Granularity | Type | Level | Overhead |
| Number of message buffer reallocations | DCSStats.numOfReallocs | Number of message buffer reallocations due to inadequate buffer size. If this number is larger than 20 percent of the number of sent messages, you may want to contact IBM Support | Per DCS stack | CountStatistic | All | Medium |
| Outgoing message size | DCSStats.outgoingMessageSize | Minimal, maximal, and average size (in bytes) of the messages that were sent through the DCS stack | Per DCS stack | AverageStatistic | All | High |
| Number of sent messages | DCSStats.outgoingMessageCounter | Number of messages sent through the DCS stack | Per DCS stack | CountStatistic | All | High |
| Incoming message size | DCSStats.incomingMessageSize | Minimal, maximal and average size (in bytes) of the messages that were received by the DCS stack | Per DCS stack | AverageStatistic | All | High |
| Number of received messages | DCSStats.incomingMessageCounter | Number of messages received by the DCS stack | Per DCS stack | CountStatistic | All | High |
| Amount of time needed for the synchronization procedure to complete | DCSStats.vsCompleteCurrentTime | Amount of time needed to guarantee that all view members are synchronized. | Per DCS stack | TimeStatistic | All | High |
| Number of messages retransmitted by local member during the view change | DCSStats.numOfVSCompletionMessages | Number of messages that were retransmitted during the view change to ensure synchronization with other members. | Per DCS stack | AverageStatistic | All | High |
| Number of times that the synchronization procedure timed out | DCSStats.vsTimetoutExpiredCounter | Number of times that the synchronization procedure timed out. | Per DCS stack | CountStatistic | All | Medium |
| Number of times that a high severity congestion event for outgoing messages was raised | DCSStats.transmitterCongestedCounter | Number of times that a high severity congestion event for outgoing messages was raised. | Per DCS stack | CountStatistic | All | Medium |
| Number of times the view change procedure timed out. | DCSStats.mbrAlarmTimeoutCounter | Number of times that membership layer alarms expired, indicating that the view change procedure timed out. | Per DCS stack | CountStatistic | All | Medium |
| Coalesce Time | DCSStats.coalesceTime | Measures the amount of time it actually takes to coalesce a view. | Per DCS stack | TimeStatistic | All | Medium |
| Join View Change Time | DCSStats.mergeTime | Measures the time to do a merge view change. The DCS stack is blocked during this time. | Per DCS stack | TimeStatistic | All | High |
| Remove View Change Time | DCSStats.splitTime | Measures the time to do a split view change.The DCS stack is blocked during this time. | Per DCS stack | TimeStatistic | All | High |
| Number of suspicions | DCSStats.suspectCounter | Measures the number of times that the local member suspected other members. | Per DCS stack | CountStatistic | All | High |
| Number of view changes | DCSStats.viewCounter | Number of times that this member underwent view changes. | Per DCS stack | CountStatistic | All | Medium |
| View group size | DCSStats.groupSize | Measures the size of the group the local member belongs to. | Per DCS stack | AverageStatistic | All1 | Medium |