SMTP archiving performance degrades when a large quantity of messages is archived from a single folder

Article:TECH201772  |  Created: 2013-01-17  |  Updated: 2014-11-27  |  Article URL http://www.symantec.com/docs/TECH201772
Article Type
Technical Solution


Issue



When SMTP archiving is configured to archive from a single folder, containing a large quantity of email messages, archiving performance degrades from what is expected.  

Due to SMTP archiving being dependent upon the File System Archiving task (FSA) the issue can be seen in the performance of the FSA task.  More information about the dependency can be found in the "Setting up SMTP Archiving.pdf", provided with the installation media.


Error



 A dtrace log capturing the EvFsaArchivingTask will show long run times of the GetArchivedItemPropertiesInBatch  stored procedure.  Times shown in the dtrace for “Time taken to execute StoreDB Query” are in Milliseconds.

13:22:49.481 (EvFsaArchivingTask)  EV-L {STOREDB.EN_US} Executing stored procedure GetArchivedItemPropertiesInBatch 
13:24:00.746 (EvFsaArchivingTask)  EV-L {FILESYSTEMITEMPROCESSOR.EN_US} Time taken to execute StoreDB Query = 71261

Cause



This issue reveals itself when the "SMTP Archiving Components” are not configured on the target SMTP server.

Explanation:
During the SMTP archiving process, new files are compared to what has already been archived from the specified folder.  The comparison of the file names is done within the SQL database.  When the destination folder within the archive contains a large number files, the SQL query run time will increase proportionally to the number of items within the folder.  As more items are archived into the single destination folder, performance will degrade.  This behavior is dependent upon the processing power of the SQL server.

Example Scenario:
SMTP server is set to place email messages in the \\SMTP_Server_Name\Email_folder_share without any subfolder structure.  The EV FSA task targets the  \\SMTP_Server_Name\Email_folder_share and archives its contents into a single folder in the FSA archive.  2 Million Messages have already been archived into the single folder within the FSA Archive and  100K+ messages still remain in the \\SMTP_Server_Name\Email_folder_share folder. Archiving performance begins to degrade as more email messages are archived.


Solution



Install the EV SMTP Archiving Components as described in the Setting up SMTP Archiving.pdf provided with the installation media or available online via the following technote DOC2200.  Once configured the SMTP server will start to use subfolders for messages, allowing the FSA archiving task to archive at expected rates.





Article URL http://www.symantec.com/docs/TECH201772


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