Why are items stuck in a 'Pending' state (or failing with Error Number 106) when being indexed

Problem

Archived items are not being indexed and there is no indication why these items have not been indexed.

Checking the 'ItemAdditionStatusLog' SQL table in the Enterprise Vault Vault Store database(s) shows that there are items detailed there with a 'Status' value of 1 or have an Error Number' value of 106.

Cause

There are a few reasons for this behavior as detailed below:

1. Indexing engine shutdown
   • If the indexing engine shuts down while data is being sent to it, it can cause a situation where Enterprise Vault believes the items have been received (because no error was received) but the indexing engine did not receive the entire batch (and so does not process it).
   • Enterprise Vault waits for the indexing engine to generate acknowledgements for these items that never arrive.
2. Indexing service stops processing an index volume abruptly.
   • If Enterprise Vault stops processing an index volume abruptly, for example to enter backup mode or subtask is stopped, then if any error reported by the indexing engine for this index volume related to the data sent can be missed.
   • This results in Enterprise Vault waiting for the indexing engine to generate acknowledgements for these items that never arrive.
3. Complex message encountered (timeout)
   • If Enterprise Vault sends a complex message (e.g. large expanded distribution list) that requires a lot of processing as it is being received) by the indexing engine (within IIS), it can take too long to send. There is a timeout (in IIS) of 30 minutes (by default) to send a ‘batch’ of items to the indexing engine. If this timeout is exceeded the indexing engine fails to process the item but Enterprise Vault waits for acknowledgements for these items that never arrive.

Solution

Items that are stuck in a pending state for too long are marked as failed (with an 'Error Number' value of 106) and are retried later.

If the item(s) continually fail to be indexed (with an 'Error Number' value of 106) then it is worth checking the possible causes to determine why this is happening and take appropriate action.