Comments on: Disabling NPTL for MySQL on RHEL4 systems

By: arjen

arjen — Wed, 31 Jan 2007 09:11:28 +0000

That was not the intent of the post.
Other people (developers) are dealing with the internals of it, that wasn’t the focus of what I wrote.

By: realmotk

realmotk — Wed, 31 Jan 2007 08:58:31 +0000

I’d be happy to follow it up for you, but using the lazyweb in the vague hope arjen or ingo or someone decides to do your homework for you is perhaps not an effective way of getting things fixed.

If someone was reporting some similar class of bug in MySQL, would you not ask for a testcase and a bug report at least?

By: arjen

arjen — Tue, 30 Jan 2007 22:38:17 +0000

Not disagreeing. Just being pragmatic about dealing with an existing situation.
Are you offering to help fix the problem?

By: anonymous

anonymous — Tue, 30 Jan 2007 22:24:04 +0000

Such hacks like disabling NPTL stops working as soon as you start using RECENT linux distribution which uses glibc 2.4 or 2.5 where there linuxthreads is no longer supported.

Anyway hacks suck badly.

By: arjen

arjen — Tue, 30 Jan 2007 19:33:21 +0000

Yes, I understand that that has been discussed. However, it’s a major architectural decision in the sense that such a change would be fairly fundamental to how MySQL works, and would require serious testing. It’s similar to this nice LL(k) parser we have “on the shelf”, putting it in place would be a very serious release on its own.
So, I’m all for it, but fixing the threading libraries would nevertheless be good.

By: arjen

arjen — Tue, 30 Jan 2007 19:31:23 +0000

MySQL 4.0 is a different issue.

By: anonymous

anonymous — Tue, 30 Jan 2007 17:08:45 +0000

Have you considered separating threads from connections in MySQL? Right now they are one and the same (class THD), plus some thread local variables are used. The thread local variables are easy to spot. I assume you want to support thousands of connections, but you don’t really want thousands of threads. This could be called MTTS (multi threaded threaded server) because MTS is taken and MySQL is already threaded.

By: anonymous

anonymous — Tue, 30 Jan 2007 16:56:09 +0000

Well, the idea that NPTL does not work with MySQL 4.0 is very well documented. Apparently they are considering a backport to deal with this.

Whether that is the issue, is uncertain since there are no versions talked about here. If there are issues with later versions and NPTL I would be very interested in details!

By: yusufg

yusufg — Tue, 30 Jan 2007 14:51:18 +0000

Can you point me to the bugzilla report which you’ve filed with Redhat about this ?

By: imajica_lj

imajica_lj — Tue, 30 Jan 2007 14:28:40 +0000

lotsa text, needs a tag