Re: DBI and threaded MPM
Anthony Gardner wrote: Perrin, I never received your mail (actually, I hardly receive any mails form this list) I have to go to the archives to see if I've received any replies or to see what's been posted in general!! You may want to check with your email admin on this. There's posting on this list almost daily!
Re: DBI and threaded MPM
On 7/11/07, Anthony Gardner [EMAIL PROTECTED] wrote: A. We recently went live with a DB application and the system ground to a halt. It could be due to many things, but the thing I'm looking at is the fact that we had many network connections. I then found the info about Databases and threaded MPM. From what I understand, DB connections created at server startup are not shared amongst threads. That's correct. Each process or thread must have a separate connection. Before you can fix your problem, you need to find out what the problem is. It sounds like you haven't done much configuration, so the most likely problem is that you have MaxClients set really high and you are using up all the memory on the machine and going into swap. There's lots of advice on the mod_perl site about how to correctly tune MaxClients and related settings. - Perrin
DBI and threaded MPM
http://perl.apache.org/docs/2.0/user/performance/mpm.html#Work_with_DataBases_under_Threaded_MPM I'm looking into a problem we're experiencing (lots of netword connections) and I think the answer lies with Apache::DBI and the version of mod_perl we're using. A few questions, does anyone know of the state of DBI::Pool? If anyone is using threaded MPM and Apache::DBI, how are they dealing with sharing the the connection within the threads? I'm looking at Thread::Sociable (preference) and threads::shared and I'm looking for tips and/or defacto stds used at the time of writing. Any tips would be great while I continue playing with threads and searching for other info. CIA -Ants - Yahoo! Answers - Get better answers from someone who knows. Tryit now.
Re: DBI and threaded MPM
On Jul 9, 2007, at 9:12 AM, Anthony Gardner wrote: http://perl.apache.org/docs/2.0/user/performance/ mpm.html#Work_with_DataBases_under_Threaded_MPM I'm looking into a problem we're experiencing (lots of netword connections) and I think the answer lies with Apache::DBI and the version of mod_perl we're using. A few questions, does anyone know of the state of DBI::Pool? If anyone is using threaded MPM and Apache::DBI, how are they dealing with sharing the the connection within the threads? I'm looking at Thread::Sociable (preference) and threads::shared and I'm looking for tips and/or defacto stds used at the time of writing. Any tips would be great while I continue playing with threads and searching for other info. Some people here ( not including me though ) are using connect_cached in DBI , and bypassing Apache::DBI altogether. you might want to try that. correct me if i'm wrong.. but i believe you want to not share dbi connections between threads. wouldn't you need a factory class to toss you a fresh connect ? if you want to do true connection pooling, you'd be best off with something like sqlrelay or pgpool. the apache::dbi/dbi cached don't really pool; they just override connects for established connections on their process and reuse them. things like sqlrelay/pgpool will let you use 50 db connections for 150 server processes ( by blocking a lot, yes ) // Jonathan Vanasco | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | CEO/Founder SyndiClick Networks | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | Founder/CTO/CVO | FindMeOn.com - The cure for Multiple Web Personality Disorder | Web Identity Management and 3D Social Networking | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - | RoadSound.com - Tools For Bands, Stuff For Fans | Collaborative Online Management And Syndication Tools | - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
Re: DBI and threaded MPM
On 7/9/07, Anthony Gardner [EMAIL PROTECTED] wrote: I'm looking into a problem we're experiencing (lots of netword connections) and I think the answer lies with Apache::DBI and the version of mod_perl we're using. Can you explain a little more about what the problem is and why you think it involves Apache::DBI? A few questions, does anyone know of the state of DBI::Pool? There is no working version of it, but Stas did write some code which someone else could pick up if they were interested. If anyone is using threaded MPM and Apache::DBI, how are they dealing with sharing the the connection within the threads? No one is doing that. It is not possible without doing some work on every DBD module that is going to be supported. I'm looking at Thread::Sociable (preference) and threads::shared and They won't work because DBD modules carry around XS structures which don't know anything about perl threads. That's the problem DBI::Pool was trying to address. May I ask why you're using a threaded MPM? Unless you're running on Windows, you should probably avoid it. The threaded MPM uses a lot more memory than the prefork one. - Perrin
