Redundancy, Synchronization, and Failover

When initial data synchronization is complete, the following SNMP trap is generated:

[Month] [Date] [Time] [hostname] snmptrapd[xxxxx]: [IP Address]:

Enterprise Specific Trap (25) Uptime: [Time], SNMPv2-

SMI::enterprises.343.2.14.1.5 = STRING: "Time : [Day] [Month] [Date]

[Time] [Year], Location : [location] , Chassis Serial # : [xxxxxxxx],

Board : CMM[x] , Sensor : CMM[x]:Datasync Status , Event : Initial Data Synchronization is complete. Asserted "

3.5.6System Health

The “Datasync Status” sensor will not contribute to the system health. However sync failures are captured by the “File Sync Failure” sensor and it contributes to the system health

3.6CMM Failover

Once information is synchronized between the redundant CMMs, the active CMM will constantly monitor its own health as well as the health of the standby CMM. In the event of one of the scenarios listed in the sections that follow, the active CMM will automatically failover to the standby CMM so that no management functionality is lost at any time.

3.6.1Scenarios That Prevent Failover

The following are reasons a failover can NOT occur:

The active CMM can NOT communicate with the standby CMM via their IPMB bus.

Not all priority 1 data has been completely synchronized between the CMMs.

To determine the active CMM at anytime, use the CLI command:

cmmget -l cmm –d redundancy

This command will output a list stating if both CMMs are present, which one is the active CMM, and which CMM you are logged in to. CMM1 is the CMM on the left when looking from the front of the chassis, and CMM2 is on the right.

3.6.2Scenarios That Failover to a Healthier Standby CMM

The scenarios listed below can only cause a failover if the standby CMM is in a healthier state than the active CMM. The health of the CMM is determined by computing a CMM health score, which is equal to the sum of the weights of the following active conditions. A CMM health score is determined for each CMM whenever any of these conditions occur on the active CMM. The CMM health score is composed of the sum of the weights of any of the three conditions listed below. Each condition has a default weight of 1 assigned to it, causing all conditions to have equal importance in causing failover.

To determine if a failover is necessary when one of these conditions occurs, the active CMM computes its CMM health score, and requests the health score of the standby CMM. If the score of the standby CMM is LESS than the score of the active CMM, a failover will occur. If a failover does not occur, the CMM SEL will contain an entry indicating the reason failover did not occur.

1.SNMPTrapAddress1 ping failure:

28MPCMM0001 Chassis Management Module Software Technical Product Specification

Page 28
Image 28
Intel MPCMM0001 manual System Health, CMM Failover, Scenarios That Prevent Failover