I currently have an application deployed using Tomcat that interacts with a Postgres database via JDBC. The queries are very expensive, so what I\'m seeing is a timeout caus
Unless your application handles request in a matter where it directly connects to the database on a per http connection basis, then you should configure your JDBC connection pool based on what your database software is set to/ can handle and your maxthreads to what your application / hardware can handle.
Keeping maxActive value (of db connection pooling) lesser than maxThreads (i.e. number of concurrent threads) makes sense in most of the cases. You can set acceptCount to a higher value depending upon what traffic you are expecting in your website and how fast one request can be processed.
Note that the HTTP connector is for incoming HTTP requests, and unrelated to JDBC. You probably want to configure the JDBC connection pool separately, such as the connectionProperties for the JDBC connector: http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html