Database error “Timed out waiting for database connection”
For On-Premise Connect customers only. This does not apply to hosted customers.
Occasionally during heavy system usage, attendees will get disconnected from a meeting, or users will be unable to access meeting content.
When searching in the debug.log files for the time when these problems occur, if you see the error messages shown below, then it is due to a configuration paramter that needs to be udpated.
2013-05-23 09:53:09 “Timed out waiting for database connection.” DB DB_CONNECTION_TIME_OUT E S – “-” – – –
2013-05-23 09:53:09 “Timed out waiting for database connection.” DB DB_CONNECTION_TIME_OUT E S – “-” – – –
2013-05-23 09:53:09 “Timed out waiting for database connection.” DB DB_CONNECTION_TIME_OUT E S – “-” – – –
2013-05-23 09:53:09 “Timed out waiting for database connection.” DB DB_CONNECTION_TIME_OUT E S – “-” – – –
2013-05-23 09:53:10 “Timed out waiting for database connection.” DB DB_CONNECTION_TIME_OUT E S – “-” – – –
2013-05-23 09:53:10 “Timed out waiting for database connection.” DB DB_CONNECTION_TIME_OUT E S – “-” – – –
2013-05-23 09:53:10 “Timed out waiting for database connection.” DB DB_CONNECTION_TIME_OUT E S – “-” – – –
The problem is that Connect is configured to have a limited number of connections to the database, and as traffic increases, users’ requests get queued up and sometimes time out while waiting for the database.
To resolve the problem, add the following line to custom.ini:
DB_POOL_MAX_SIZE=3000
This will create a large pool of database connections and should ensure that no connection requests are denied due to timeout issues.
There is another setting in the custom.ini, that affects the Database connectivity: DB_LOCK_TIMEOUT
Is there a need to change this value also (at our installation we have a value of 50)?
The DB_LOCK_TIMEOUT setting indicates how long a query will wait in a lock condition before it times out, incomplete. While it does affect timeouts, it would not resolve the issue addressed in this blog post. For this instance, there are too few connections in the pool to handle the volume of requests, so it is necesary to increase the size of the available pool.
Thanks for your answer. Is there a way to monitor amount of connections to sql server?
Yes, this can be done at the SQL Server level using Microsoft tools. Here are a couple of pages with more information about SQL Monitoring:
http://technet.microsoft.com/en-us/library/ms175518.aspx
http://msdn.microsoft.com/en-us/library/ms179428.aspx