WebDAV Query generates a high number of transaction log files
Hi all,I have a program that launch WebDAV queries to search for contacts on an Exchange 2007 server. The number of contacts returned for each user's mailbox is quite high (about 4500).I've noticed that each time the query is launched, about 15 transaction log files are generated on the Exchange server (each of them 1Mb). If I ask only for 2 properties on the contacts, this number is reduced to about 8.This is a problem since our program is supposed to launch often (about every 3/5min) as It will synchronize Exchange mailboxes with a SQL Server DB. The result is that the logs increase very quickly on the server side, even if there are not so many updates.Any idea why so many transaction logs are generated when doing a WebDAV search returning many items? I would understand that logs are created when an update is done on the server, but here it's only a search with many contacts items returned.Is there maybe a setting on the Exchange server to control what kind of logs to generate?Thank for your help,Alexandre
January 21st, 2009 2:39pm

Hi Alex,Do you mean that transaction logs, which have names something likeEnnxxxxxxxx.log, are being generated when you do WebDAV queries?Transaction logs: Before changes are made to an Exchange database file, Exchange writes the changes to a transaction log file. After a change has been safely logged, it can then be written to the database file. Further detail:http://technet.microsoft.com/en-us/library/bb331951.aspxAcutally there isn't any setting on server to control transcation logs. Whenver any transcation occurs (send/recieve email or move/copy the mailbox data) logs are being generated.There is a way to configure transcation logs to circuler logging which uses same log file when data has been written to Exchange database to secure the drive space but it is NOTrecommend as a best practice in normal condition because it does not allow a roll-forward recovery after a backup has been restored when any disaster happens you are in loss of data from the point you have full backup to the point of disaster.Basically you need to find out, what the program does internally when you do WebDAV query, ask to the developers or the vendor of the porgram to give more details if program does any temporary transaction in any mailbox or location.Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com
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January 21st, 2009 4:09pm

Thanks for your answer Amit.Yes I'm talking about these files named Ennxxxx.logI've actually reproduced the problem in a very simple program that simply launch a WEBDav Query against the contacts folder on a user's mailbox. The query returns 4350 contacts.When I look at the server right after the query was launched, I immediately see 15 transaction log files created. All of them seem to contain information about the contacts that were returned from the query. Although the file is binary, I can see some entries like "I P M . C o n t a c t" followed by the name, phone or some other info from the contact. There are hundreds of entries like that in each of the 15 log files, so I guess it generated logs for each of the 4350 contacts returned.In my sample, I'm sure that only the query is launched to the server and nothing else when the search is launched (I've especially used Fiddler to see what request are being to the server).So Exchange really seems to write logs when it build the search results to be returned from the WebDAV query, although no updates are done on the mailbox (at least not be me).I was hoping there could be another solution rather than setting circular logs, or more frequent backups.Alexandre
January 21st, 2009 5:55pm

Hi Alex,Actually circular logging/backup was not a solution, I was just explaining that there is an option like that on server but it is not recommended hence not useful in our case :)- I am not a developer butAFAIK,WebDAVsearch query shouldn't generate transaction log because it just searches the mailboxes and gives the result inHTTPformat and doesn't produce any Exchange transaction.- I wouldn't open transaction logs since it is being used by Exchange which may generate errors and may corrupt Exchange databasesometimetoo. However it is not readable, as you observed, other than Exchange Information Store service (store.exe).- You can post this query in development forum to get better idea on this, if any other programmer observed similar symptom while usingWebDAVcontact search query in Exchange 2007 or can validate yourquery.MicrosoftTechNet>Forums Home>Exchange Server>DevelopmentWell, I just saw that you are using Exchange 2007, in that case why don't you use Exchange Web Service which is better and improved method to access/query mailboxes where asWebDAVis also de-emphasized in Exchange2007 and might be disappeared in next version of Exchange. Checkout below article for further detail.Development: Overviewhttp://technet.microsoft.com/en-us/library/aa997614.aspx Amit Tank | MVP - Exchange | MCITP:EMA MCSA:M | http://ExchangeShare.WordPress.com
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January 21st, 2009 7:31pm

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