Diagnose the cause of a collection update failure


This article goes through the process of troubleshooting a collection that has failed to update.


For this scenario you are alerted to an issue due to a collection update failure being recorded. This could be either by observing a collection failure status when logged in to the administration interface, or by receiving a failed update email (if the admin email for the collection is configured).

Each time a collection is updated, an update log containing status information about each stage of the update process is created. These update logs are named update-<COLLECTION-ID>.log and can be viewed in the log viewer.

The update log contains several lines relating to the completion status of each stage in the update process. Sometimes it is possible to immediately diagnose the problem from the error message in the update log. Otherwise it will be necessary to examine the detailed log file of the stage that failed. These detailed logs can be viewed by clicking the links under the offline log files folder in the log viewer.


  1. View the update log (update-<COLLECTION-ID>.log) from the collection-level update logs, available from the log viewer in the administration interface. This will provide high level information on the status on an update.

  2. Check the live/offline update logs for the collection for details on the error. These are contained within the live and offline log folders, again accessed via the administration interface log viewer. The folder that you inspect will depend on the state of the collection and what you are trying to debug.

    Inspect the offline logs folder if:

    • The update failed and you are troubleshooting the cause of the failure.

    • The collection is currently updating and you wish to view logs relating to the currently live search indexes.

    • The collection is not currently updating and you wish to view the logs relating to the previously successful update.

      Inspect the live logs folder if:

    • The collection is not currently updating and you wish to view the logs relating to the currently live search indexes.

  3. Inspect the update.log of the relevant view (live or offline). This log provides the top level logging for each of the steps within the update pipeline. It should provide information on where within the update pipeline the error occurred.

  4. Use the information on where the error occurred to inspect the more detailed logs. For example, if the gather process failed then view the gather logs that correspond to the collection type. If the error occurred during indexing then inspect the indexing logs.