Product Documentation

Limiting Failovers Caused by Route Monitors in non-INC mode

Aug 28, 2013

In an HA configuration in non-INC mode, if route monitors fail on both nodes, failover happens every 180 seconds until one of the nodes is able to reach all of the routes monitored by the respective route monitors.

However, for a node, you can limit the number of failovers for a given interval by setting the Maximum Number of Flips and Maximum Flip Time parameters on the nodes. When either limit is reached, no more failovers occur, and the node is assigned as primary even if any route monitor fails on that node. If the node is then able to reach all of the monitored routes, the next monitor failure triggers resetting of the Maximum Number of Flips and Maximum Flip Time parameters on the node and starting the time specified in the Maximum Flip Time parameter.

These parameters are set independently on each node and therefore are neither propagated nor synchronized.

Parameters for limiting the number of failovers

Maximum Number of Flips (maxFlips)

Maximum number of failovers allowed, within the Maximum Flip Time interval, for the node in HA in non INC mode, if the failovers are caused by route-monitor failure.

Maximum Flip Time ( maxFlipTime )

Amount of time, in seconds, during which failovers resulting from route-monitor failure are allowed for the node in HA in non INC mode.

To limit the number of failovers by using the command line interface

At the command prompt, type:

  • set HA node [-maxFlips < positive_integer>] [-maxFlipTime <positive_integer>]
  • show HA node [< id>]
Example
> set ha node -maxFlips 30 -maxFlipTime 60 
 Done 
> sh ha node  
1) Node ID: 0 
 IP: 10.102.169.82 (NS) 
 Node State: UP 
 Master State: Primary 
 Fail-Safe Mode: OFF 
 INC State: DISABLED 
 Sync State: ENABLED 
 Propagation: ENABLED 
 Enabled Interfaces : 1/1 
 Disabled Interfaces : None 
 HA MON ON Interfaces : 1/1 
 Interfaces on which heartbeats are not seen :None 
 Interfaces causing Partial Failure:None 
 SSL Card Status: NOT PRESENT 
 Hello Interval: 200 msecs 
 Dead Interval: 3 secs 
 Node in this Master State for: 0:4:24:1  
 (days:hrs:min:sec) 
2) Node ID: 1 
 IP: 10.102.169.81 
 Node State: UP 
 Master State: Secondary 
 Fail-Safe Mode: OFF 
 INC State: DISABLED 
 Sync State: SUCCESS 
 Propagation: ENABLED 
 Enabled Interfaces : 1/1 
 Disabled Interfaces : None 
 HA MON ON Interfaces : 1/1 
 Interfaces on which heartbeats are not seen : None 
 Interfaces causing Partial Failure: None 
 SSL Card Status: NOT PRESENT 
 
Local node information: 
 Configured/Completed Flips: 30/0  
 Configured Flip Time: 60  
 Critical Interfaces: 1/1  
 
Done 
To limit the number of failovers by using the configuration utility
  1. Navigate to System > High Availability and, on the Nodes tab, open the local node.
  2. Set the following parameters:
    • Maximum Number of Flips
    • Maximum Flip Time