What is the default MaxPoolSize?

Question

I am getting the dreaded error:

Timeout expired. The timeout period elapsed prior to obtaining a connection from 
the pool. This may have occurred because all pooled connections were in use 
and max pool size was reached.

In sql I see that I only have 116 connections open by running:

SELECT 
    DB_NAME(dbid) as DBName, 
    COUNT(dbid) as NumberOfConnections,
    loginame as LoginName
FROM
    sys.sysprocesses
WHERE 
    dbid > 0
GROUP BY 
    dbid, loginame
;

116 seems low, and I am currently not setting the MaxPoolSize. What is the default MaxPoolSize?

I have also made sure all my connections are closed when finished.

Answer 1

From MSDN: maximum pool size specified (100 is the default).

That what you have is a Timeout error. It only suggested that it might have been caused by max pool size being reached, but it could have happened for many other reasons.