Description

How to stop/terminate In-Service Software Upgrade (ISSU) process in case it stalls in the middle of the upgrade.

Symptoms

At times, customers would like to upgrade their production SRX cluster devices with minimal downtime, and most often the practice followed is to use the ISSU process to achieve this.
It so happens that at times, ISSU may not complete correctly which lead to cluster problems including session synchronization and correct recognition of peer.

Solution

If the system did not complete the ISSU process, perform the following steps to completely stop the ISSU process and rollback to previous state.

  •  If both nodes completed the upgrade (verify with the command 'show version') run the following commands on both nodes simultaneously to rollback to the previous Junos version.
request chassis cluster in-service-upgrade abort
request system software rollback
request system reboot
 
  • If only one node completed the upgrade (verify with the command 'show version') run the following commands:
    1. On the upgraded node (with the rollback command mentioned below, the upgraded node will be back to the older version post-reboot)
      request chassis cluster in-service-upgrade abort
      request system software rollback node local
    2. On the node that did not complete the upgrade
      request chassis cluster in-service-upgrade abort
    3. On both nodes after completing the above steps 
      request system reboot
  • If neither node completed the upgrade successfully (verify with the command 'show version') run the following commands on both nodes simultaneously to rollback to the previous Junos version
    request chassis cluster in-service-upgrade abort
    request system reboot

Refer to KB17946 [juniper.net] for ISSU non-supported features that may impact ISSU upgrades.
Refer to KB17947 [juniper.net] for minimal downtime upgrade procedure.

 

Note: Recommendation is to perform above steps in the maintenance window to avoid any traffic impact.

Modification History

 

2026-06-18: Updated the solution line with a note.

2023-08-24: Added the explanation for step(1) in the solution section.
2021-03-25: Updated the article terminology to align with Juniper's Inclusion and diversity initiatives.