Loosing Database Connectivity

[Guest miva]

Hello,

 

We have a problem with more than one server where database connectivity stops working (to any datasource), queries all start timing out, however if we manually do a query they are quick and working correctly independant of VG.

 

The only way to fix it is to stop VG and restart the service, it then works fine again for a short time (sometimes an hour or two) and then stops again.

 

We went to update to the latest version of VG, however the download file tripped our anti virus software (Nortons) which indicated the download was not safe and was therefore removed: [old link removed]

 

The norton serverity was "HIGH" and the message was "Suspicious.Cloud.9" detected. File was quarantined.

 

I've attached log files kt_Tel and vgEngine. We manged to find an instance where it happened quickly, so the logs are relatively short.

 

Your assistance is appreciated.

 

Regards,

Miva

[Guest miva]

Sorry I'm not sure the Zip attached. So here it is, feel free to remove this thread after download.

0124_1416_Logs.zip

[SupportTeam]

Just downloaded v7.4.2 from website and uploaded it to VirusTotal.

 

All anti-virus / anti-malware engines used by VirusTotal gave it an all-clear.

 

Results can be seen here:

 

https://www.virustotal.com/en/file/14114b2a53aeba2715960b1201ec6ed966755e22ce085afe1c7f8aa990130e00/analysis/1390537421/

[SupportTeam]

Looks like your script is accessing MS Access databases.

 

Trace shows that VoiceGuide issues a command to connect to the database using the .NETs System.Data.OleDb.OleDbConnection (connector used for MS Access).

 

We can see in trace that the database open commands work for a while (160 queries are successful) but then all of a sudden the OleDbConnection.Open call just does not return.

Attached db.txt trace shows "db oledb connection open call " is usually followed by "db oledb connection open returned." - sometimes waiting for a previous connection to complete. But then it just stops responding.

 

We can see that calls the MS Access database are sometimes being queued - with new queries starting before previous ones complete. Maybe this is the reason for your problems - MS Access may have issues handling multiple concurrent queries.

 

BTW. whenever you see in VoiceGuide trace "db oledb ConnectAndRun_OleDb thread completed." this means that the MS Access connection .Close() call has completed. So VoiceGuide is not leaving any database connections open.

 

You could maybe try setting up an ODBC connector for your databases and using these MS Access databases via ODBC to see if this fixes anything, but ultimately the recommendation here would be to use a different database (SQLServer, MySQL, PostgreSQL, etc)

142630.906  4  31  11       db    oledb ConnectAndRun_OleDb begin. Create connection: [Provider=Microsoft.Jet.OLEDB.4.0;Data Source='C:\Program Files\VoiceGuide\Scripts\MCR\rmvd\NSW_Service_Warranty\Queuing.mdb']
142630.906  4  31  11       db    oledb connection open call [Provider=Microsoft.Jet.OLEDB.4.0;Data Source='C:\Program Files\VoiceGuide\Scripts\MCR\Actron\NSW_Service_Warranty\Queuing.mdb']
142630.937 21  31  11       db    oledb ConnectAndRun_OleDb thread completed.
142630.937  4  31  11       db    oledb connection open returned.
142630.937  4  31  11       db    oledb m_strSQL=[UPDATE LiveStats SET Status='Offline', TotalTime=230, CallerID='0288144000' WHERE QueueID=51 AND LineID=11 AND System=1;]
142638.906  6  40  14       db    oledb RunQuery_OleDb AgentHeartbeat, C:\Program Files\VoiceGuide\Scripts\MCR\Actron\NSW_Tech_Support\Queuing.mdb, , UPDATE Agents SET Connected=1, HeartBeat=#01/24/2014 14:26:38# WHERE Name='removed'
142638.906 21  40  14       db    oledb ConnectAndRun_OleDb begin. Create connection: [Provider=Microsoft.Jet.OLEDB.4.0;Data Source='C:\Program Files\VoiceGuide\Scripts\MCR\rmvd\NSW_Tech_Support\Queuing.mdb']
142638.906 21  40  14       db    oledb connection open call    <- never gets response

db.txt

[SupportTeam]

Maybe some other user/process is using your MS Access databases and hence blocking new connections from opening to them?

 

These kinds of issues with MSAccess are the reason why this DB should not be used in environment where multiple users/processes need to issue queries to it.

[SupportTeam]

This is the latest versions of v7.4.2. Please update to this version: [old link removed]

 

Another thing to look at may be to disable connection pooling by using this parameter in your connection string:

 

OLE DB Services=-2

 

(see: http://www.c-sharpcorner.com/uploadfile/mahesh/understanding-connection-pooling-in-ado-net/ )