Message "Archive and index out of sync" is displayed for some Index Volumes in Accelerator Searches

Problem

Enterprise Vault (EV) Compliance Accelerator (CA) and Discovery Accelerator (DA) have the ability to run Searches to find items that meet the search criteria as specified by the user running a CA or DA Search . The search progress can be viewed in the Search Details pane in the Searches Tab of a CA Department/Research Folder or a DA Case/Research Folder. A drop-down menu allows for the filtering of Index Volumes that are running the search based on their status. The currently available statuses are:

Top 2000 archive indexes by hits
Bottom 2000 archive indexes by hits
2000 failed/error archive indexes
2000 abandoned archive indexes
2000 not started archive indexes
2000 queued archive indexes
2000 retrying archive indexes
2000 finished archive indexes

Some Index Volumes under Top 2000 archive indexes by hits, Bottom 2000 archive indexes by hits, or 2000 finished archive indexes may display in the Information column the message noted in the Error Message section below when there are no hits.

This message is not a warning, exception or error message; it is simply an informational message, as described below. Additionally, the same message will also be listed for these Index Volumes in the comma-separated values (CSV) file that is generated when clicking on the Download Search Details for all Archives link in the Search Details pane.

Error Message

Archive and index out of sync. (archive is being updated)

Cause

The normal behaviour of EV Archiving and Indexing is that items are Indexed after they are Archived. This means EV Indexing will be slightly lagging behind EV Archiving as it processes newly Archived items to be Indexed. When there are newly Archived items that have not been Indexed, the EV Indexing engine sets the Index Volume to a status indicating items need to be Indexed and then begins the process of obtaining the newly Archived items and Indexing them. Where there are no more newly Archived items to be Indexed, the EV Indexing engine sets the Index Volume to a status indicating no more items need to be Indexed.

During a CA/DA search's execution, CA/DA will send the search criteria to EV Indexing for the Indexing engine to run the Search against EV Index Volumes targeted by the search criteria. The Indexing engine will find search hits based on the Indexed items that are available in EV Index Volumes at the time that the search was run.

When the search hits are returned to CA/DA by EV Indexing, the status of the Index Volume is also returned, i.e., whether or not the Index Volume is actively processing newly Archived items. This status is in the form of a flag called InSync which indicates if the Index Volume is in sync with Archiving (no items being actively Indexed) or not in sync with Archiving (there are newly Archived items that are being Indexed).

If the InSync flag is true, there is no special informational message required nor displayed in the CA/DA Client.

If the InSync flag is false, this indicates the Index Volume is being actively updated with newly Archived items and it may not contain the Index information for these newly Archived items. This means the search results may be, but not necessarily, incomplete. To indicate this to the search creator when there are no hits, the message Archive and index out of sync. (archive is being updated) is displayed in the Information column in the Search Details pane simply as a reminder for the search creator to review the potential need of re-running the search at a later date based on the search criteria and the potential need of including the newly Archived items that may not have been present in the Index Volume when the search was originally run. When there are hits, this informational message is not displayed as the Index Volume has successfully returned all available hits that matched the search criteria.

Please note that in either case, the Index Volume has successfully processed the search criteria based on the items present in the Index Volume at the time the search was run. If the same search was re-run at a later date and the newly Indexed Items, i.e., items that were Indexed after the previous Search was run, match the search criteria, then they will appear as search hits.

Here are some other scenarios that might be encountered when running searches:

- If an Index Volume is undergoing the Rebuild operation, the original Index Volume information will be used for a search until the newly rebuilt Index Volume is fully online. The original Volume is not offline but is set to Read Only mode so that no new items are added to that Volume during the Rebuild. The search would complete successfully against the original (Read Only) Volume and either return hits that matched the search criteria or log the informational message Archive and index out of sync. (archive is being updated) if no hits were found that matched the search criteria.

- If an Index Volume was deleted and then a Rebuild was initiated, the Search would fail and list the failure message Index Search failed: %1 Index: %3 Internal reference: %2 (0xc0041c0e) since the old Index Volume was not available in a Read Only mode to be Searched and the new Volume is still in the Rebuild process and not ready to be searched.

- If an Index Volume is in an Offline state, the search would fail and log list the failure message: The search could not be performed due to the index not being searchable..

- If an Index Volume is not active, i.e. no new items are being added, and there are some missing items, the search would list the message Items or content missing from the index. In this case, the search will find whatever is present in that Index Volume. It will be the decision of the search submitter to review this message and determine if the search results are accurate or if the search needs to be re-run after addressing any missing items from the Index Volume and then verifying the Volume is healthy.

- If an Index Volume is not active, i.e. no new items are being added, and a Synchronize operation is run against the Index Volume, a Search that returns no hits may list the following message: Archive and index out of sync. (archive is being updated); Items or content missing from the index. In this case, it is best to wait until the Synchronize operation is complete and then re-run the search.

Solution

In summary, if the Search Details pane or CSV file list the informational message Archive and index out of sync. (archive is being updated) when there are no hits and the Index Volume displaying this informational message is listed under Top 2000 archive indexes by hits, Bottom 2000 archive indexes by hits or 2000 finished archive indexes, this informational message simply provides a hint for the Search creator to review the search results based on the search criteria and make a determination if there is a potential need to re-run the search at a later date based on the search criteria and the possibility of newly Indexed items meeting the search criteria. The search itself has completed successfully against that Index Volume.
 
This is expected behaviour and is not a defect.