connection-pooling

In the Java world it is pretty standard for app servers to pool "expensive" resources, like DB connections. On the other hand in dynamic languages, most stacks have little to do with pooled resources and especially DB connections. E.g. for the popular PHP+MySQL combo, I've rarely seen it used with persistent connection, which can be considered poor-mans pooled connections. If the concept of pooling DB connections is not that widely implemented, does this mean that the performance/scalability gains might not be all that important, in real-life deployments? The main reason for connection pooling

Question: Lot of active unclosed physical connections with database even with connection pooling. Can someone tell me why is it so? I configured the connection pool settings using oracle.jdbc.pool.OracleDataSource . However it seems the physical connections are not getting closed after use. I thought, Since it is connection pooling, the connections will be reused from the pool, so so many physical connections will not be made, but thats not what is happening now! There are 100+ active physical connections in the database generating from the application [not from plsql developer or any such

I am looking for a robust connection pooling library for Postgresql. Something similar to https://github.com/dweldon/riakpool would be great. Poolboy is a pretty good general-purpose pooling library: https://github.com/devinus/poolboy It comes with an example of how to use it with pgsql (scroll down the README file). 来源： https://stackoverflow.com/questions/7767415/postgresql-connection-pooling-in-erlang

Greetings, I'm looking for a good solution for externalizing the JNDI connection pool information in context.xml of a war so that as the application moves from dev to QA to prod, the war file won't need to be recompiled. Ideally the url, driver, username and password would be variablized and then populated by means of a properties file that would customized for each environment. If this isn't possible, are there other suggestions on how to handle moving a war across environments without recompiling for a target environment? Maven provides profiles this requires a build targeted at a specific

I'm trying to debug what seems to be an excessive number of database connections being opened and closed despite the fact that we are using the Tomcat 7 JDBC connection pool. How can I log when calling getConnection() on the data source results in a new connection being opened versus an existing connection being borrowed from the pool? I have faced a similar case today. I log through slf4j, and my problem was caused by hibernate. What I've done is setting up in the log configuration the space where the JDBC connection getter is called. Fortunately, for hibernate there are logs at debug level

An answer from here Typically, opening a database connection is an expensive operation, so pooling keeps the connections active so that, when a connection is later requested, one of the active ones is used in preference to opening another one. I understand the concept of Connection Pool in DB management. That is the answer for a " what is ~ " question. All developers blog posts, answers, tutorials, DB docs out there always answer for a question " what is ". Like they constantly copy/paste text from one another. Nobody tries to explain " why is it so " and " how ". The answer above is an