The log space used for message box database periodically increases upto the order of 14 GB and the performance of BizTalk becomes slow. This happens intermittently.
ISSUE
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The log space used for message box database periodically increases upto the order of 14 GB and the performance of BizTalk becomes slow.
This happens intermittently.
CAUSE
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The issue occurs if the Backup BizTalk Server job is scheduled to perform log backups for long span of interval.
By default Backup BizTalk job is scheduled to perform log backups for every 15 minutes.
But in this case the customer had the Backup BizTalk Server job scheduled to perform log backups for every three hours. In such cases the Backup BizTalk job will not purge the logs from the message box until every 3rd hour and it continues to consume space in memory until next run which happens after three hours.
So in such scenarios, under heavy load, the log space used for message box database increases up to the order of 14 GB when we are about to reach the three hours mark and it will be as low as 2 Gb once we reach the 3 hours mark when the Backup job will purge the logs from the message box database.
RESOLUTION
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Please make sure that the Backup BizTalk Server job is scheduled to perform log backups in a shot interval of time. By default this job performs log back up for every 15 minutes.
You can check the scheduling of his job under Schedule column in the message box viewer report under BizTalk jobs List.