Log Messages Generated for Stateful LM Switchover

When you configure high availability for line modules and SRP modules, the modules that support stateful switchover record log messages and SNMP traps when they transition to different switchover states, such as disabled, initializing, and active.

In releases of JunosE Software that did not support high availability for line modules, the logging messages for the ha event log category displayed information about high availability functions that were specific to SRP switchover operations. Although the log messages were associated with SRP switchover, the high availability details in the recorded messages did not explicitly indicate that the information was relevant to only SRP modules.

In JunosE releases that support high availability for line modules, the existing messages for the ha log event category have been enhanced to uniquely distinguish the changes to switchover states for line modules and SRP modules. The following examples describe logging messages generated when SRP modules and line modules transition from one state to the other during the switchover process.

Log Messages Displayed During the Transition from Disabled State to Active State

In the disabled state, which is the default state for high availability mode, the router uses redundancy mode for line modules (if a standby line module is configured for switchover purposes). If all criteria are met for the system to shift from the disabled state to begin bulk synchronization of the memory, high availability mode transitions to the initialization state. After initialization is completed, the system enters the active state. The following log messages are saved for SRP modules and line modules when the system moves from the disabled state to the active state. You must configure the high availability log event category using the logging severity ha command in Global Configuration mode to enable logs related to high availability operations to be recorded.

Log Messages Displayed During the Transition from Active State to Pending or Disabled State

When an unsupported application is configured after HA is active on the line module, the application is regarded as unsafe for HA. The state machine on the line module transitions to the disabled state. For SRP modules, the system transitions to the pending state. The following sample log messages are generated for SRP modules when the system transitions from the active state to the pending state, and for line modules when the system transitions from the active state to the disabled state:

Log Messages Displayed During the Transition from Pending or Disabled State to Active State

The system transitions to the pending state if an unsupported application is configured for SRP modules. For line modules, when an unsupported application is configured, the system transitions to the disabled state. After the configuration of the unsupported application is removed, the system moves from the pending or disabled state to the active state. The following sample log messages are generated for SRP modules that are configured for high availability when the system transfers from the pending state to the active state, and for line modules when the system transfers from the disabled state to the active state:

Log Messages Displayed During the Transition from Active or Pending State to Disabled State

From the active state, the system changes to the pending state if an unsupported application is configured for SRP modules. From the active state, the system changes to the disabled state for line modules if an unsupported application is configured or if any other criterion is not satisfied for remaining in the active state. The following log messages are generated for SRP modules and line modules that configured for high availability when the system transfers from the pending state or the active state to the disabled state:

Log Messages Displayed for Stateful SRP and Line Module Switchover When HA Is Enabled

The following log messages are displayed for SRP modules and line modules when stateful switchover is enabled for those modules.

Log Messages Displayed for Stateful SRP and Line Module Switchover When HA Is Disabled

The following log messages are displayed for SRP modules and line modules when stateful switchover is disabled for those modules. Any failure or restart of the secondary line module causes high availability to move to the disabled state.