Data Sync Group wont start - no obvious errors

Question

Hello.

We have a Data Sync Group from Azure to On-prem that was working fine.

A few days ago it generated an error due to a lack of memory:

Sync failed with the exception "Cannot enumerate changes at the ************ for table '************'.    
Check the inner exception for any store-specific errors.Inner exception: Insufficient memory to continue the execution of the program.   

I restarted the on-prem sync agent in hopes that would solve the issue.

Since then the Sync Group will not actually sync. (It has a constant "Warning" status but no logs with errors)

Each attempt to satrt the sync shows one log entry: Tombstone cleanup completed successfully. 0 rows deleted.

But nothing more. I enabled logging on the on-prem agent but there is no mention of the sync group in the log (which does refer to others running ok)

Its like it is now a "ghost" sync group that appears ok in azure but has no real implementation.

All help appreciated

Bill

Answer 1

I have seen that error "Cannot enumerate changes at the ..." when schema changes have been applied on the database but not related to out of memory error condition.

Please consider to stop and delete the sync group related to the table specified on the error "Cannot enumerate changes at the ..." after that recreate the syn group. If that table is big, put it on a separate sync group just for that table.

Make sure the computer where the agent is installed has enough memory to handle SQL Data Sync activity.