On Tue, Dec 2, 2008 at 6:16 PM, Christopher Jones < christopher.jones@xxxxxxxxxx> wrote: > Themis Vassiliadis wrote: > > > > On Tue, Dec 2, 2008 at 4:18 PM, Christopher Jones > > <christopher.jones@xxxxxxxxxx <mailto:christopher.jones@xxxxxxxxxx>> > wrote: > > > Oracle 11g DRCP support is available in PHP. See this whitepaper: > > > http://www.oracle.com/technology/tech/php/pdf/php-scalability-ha-twp.pdf > > Change the connection string slightly, and set one new php.ini > > parameter to > > use it. > > > > Chris > > > > I think that DRCP is a work around solution. > > I disagree. It is a major technology feature that enables pooling for > a wide variety of client programs. It is extremely scalable. The > whitepaper shows results from a small, commodity computer handling > 20,000 concurrent connections. > > > Of course is much better than traditional connections as we had > > before 11G. > > > > But I think that is really possible to develop a new extension working > > like Java component Apache DBCP. This is a traditional pooling > > mechanism, where is defined in a xml file the pooling description and it > > is ensured that just applications behind Tomcat will use the pool. > > The advantage of DRCP is precisely that it is server side: all your > mid-tier application servers share the one pool on the DB server. It > becomes easier to add web server machines, and their configuration is > simpler. > > > So if imbedded in an extension, the pool will start just when apache > > starts, and will down when apache stops. And the whole pooling > > definition will be at the client side. > > The main problem with mid-tier multi-threaded pooling solutions is > that PHP is mostly run single-threaded because some PHP extensions are > not thread safe. > > > Pooling is a solution created for web applications, the DRCP, if I'm not > > wrong, should be used from web and client applications like SQL Plus. > > They just need to select the TNSNAME key and use the pool. > > When the DRCP server pool is started, applications can choose to use > it, or they can continue to use "dedicated" connections if they want. > > > Chris > > -- > Email: christopher.jones@xxxxxxxxxx Tel: +1 650 506 8630 > Twitter: http://twitter.com/ghrd Free PHP Book: > http://tinyurl.com/f8jad > DRCP is really a big improvement. But for me it has a great holdback: the pool controlled in the server side isn't defined for a specific schema, so if we have an application server serving different connections demanding different credentials certainly the performance will be worse. Another big problem is that one application hosted in the web server can lock the pool completely is the demand for this application improve. In other hands if we work with traditional pooling, configured in the client side, we should define one pool for each aplication with his own credentials. The pool will never blocked by one system and for hosts with several credentials the performance will be better. The performance and availability will be insured. Of corse both are good solutions, each one for your specific purpose. -- Themis Vassiliadis
