Thanks Chris, Would the expensive opening database connection a issue while using Named Pipes ? (is the cost mostly coming from TCP 3 way or the xact setup/resource allocation on the db side for a new inbound connection ?)
Ran On 12/13/06, Christopher Schultz <[EMAIL PROTECTED]> wrote:
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Ran, Ran wrote: > In this > case, my bean should hold up on one connection until the bean instance gets > gc'ed (for a request/ session scope bean) You can never count on an object to get GC'd: you should always explicitly free resources whenever you are actually done with them. So, if you have a bean that needs a connection, get the connection, use it, and then return it to the pool (or close it, which is usually the same thing when using pooled connections). > For a bean that persists in application scope, I would close the connection > after query finishes. > > Do pooled connections remain open in the container while idle? Yes. That's the whole point of pooling. Most database connections have a high cost to establish, so you get better performance by holding idle connections open waiting for some request to use them. If you open a new connection for every request that needs one, you suffer from two problems: 1. Resource management. If you get a flood of traffic all at once, you could open up many database connections and bring your database to its knees. Any decent connection pool can limit the number of connections it holds, so you know there is an upper limit on the number of in-use database connections at any one time. 2. Performance. Opening a new connection each time you want to access your database is costly. If you open up your connections on app start, then you only pay the penalty that one time. Otherwise, you will pay that penalty for every request that needs a database. - -chris -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.6 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFFgB+e9CaO5/Lv0PARAhdeAJ9CFR2143im9CWvrTnF8exIkq169gCeK9JB 4ILIuRcvXzHOYIkg9qd63ao= =3XJq -----END PGP SIGNATURE----- --------------------------------------------------------------------- To start a new topic, e-mail: users@tomcat.apache.org To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
