TYPO3 hogging

Well, we do appear to be having some strange load problems with our main TYPO3 box hosting several home pages of the local universities, as you can see below.

LOAD on t3node1 between 05:00-19:00 on 2008/04/07
LOAD on t3node1 between 05:00-19:00 on 2008/04/07

We repeatedly tried to figure out which of them was the one responsible, but neither I nor the other Unix sysadmin knew a better way to figure out the load each TYPO3 installation was causing (since there ain’t no phptop or something similar). But since today the new semester started, we figured it might be good to finally figure which one it was. And a few minutes (as in one or two) wouldn’t be much of a problem compared to the advantage we’re getting out of it.

As a comparison, here’s the “normal” load for the last week:

LOAD on t3node1 between 2008/03/31 and 2008/04/07
LOAD on t3node1 between 2008/03/31 and 2008/04/07

So as a last resort (because of said load problems), we simply deactivated one vHost after another, until the load started to relax. Unsurprisingly it was one of the installations that had problems before. Let’s see whether or not the people over at said university are insightful or not … πŸ˜†

OCFS2 follow-up

OK, it turned out that said colleague wasn’t responsible at all. Turns out, the *real* trigger was me creating a new volume on our SAN, on the same array that houses the OCFS2 volume.

Apparently, during creation of an additional SAN volume, all other SAN volumes in this array are either read-only or delayed during that time, as you can see from the following log:

OCFS2 fun yet again

I’m coming back today from a six day vacation in the warm south (that is Stuttgart), back at work and find three sheets of paper on my desk. Two tell me something I haven’t done yet, the other one tells me something I haven’t seen yet.

One of my colleagues had to restart one of our web nodes and now the thing can’t mount the logging volume (and thus, logrotate / awstats failed to do it’s job). OCFS2 ain’t spitting any error messages, when trying to mount the volume you see it joining the domain the volume belongs to on the other nodes, so from a first glance at things .. nothing is wrong ?

One thing I’ll have to add is, that you can’t reboot the box cleanly (as in you have to use the power button, so I figure something is either stuck or something is malfunctioning ..) *shrug*

Zend Optimizer again

Well, I happen to be back at my favorite application. Today I stumbled upon a “nice” thing. If you turn on the Zend Optimizer (doesn’t matter whether it is 2.6.2 or 3.3.0), one of the TYPO3 back ends ain’t showing *any* content in the preview pane. Once you turn the Zend Optimizer stuff off, it works without a problem.

O RLY ?
O RLY ?

And as Zend stated on their “Support Forum“, they don’t really support the Zend Optimizer stuff in the first place. Which is nice, what for do you need the Zend Guard shit in the first place ??

Well, so I do have two options now:

  1. Disable the one plug-in, which really needs the Zend Optimizer (as it also features the Zend De Guard engine – or whatever you want to call it)
  2. or risk some other things breaking due to the Zend Optimizer engine not working (correctly) with php-5.1.2 (which is rather old considering 5.3.0 is in development right now)

But I will see about that tomorrow …

YA RLY!
YA RLY!

Been a while

Well, it’s been quite a while since most of the people last heard a word from me. The last few months I’ve been extremely busy with work-related tasks (and as a side-effect of that, didn’t want to spend much time in front of the computer after 9 hours of work). I also started spending more and more time in the gym, like nearly two hours every Tuesday and Thursday.

  • I finally fixed our replication issues, we do now have a working! MySQL Multi-Master (1. Node, 2. Node — bear in mind, this boxes are *only* serving MySQL and nothing else, so don’t use these configurations on mixed setups) Replication Setup as database back end for our TYPO3-vHosts.
  • all the web nodes are now serving the content from a clustered, shared SAN volume (is that a good thing ? πŸ˜› – don’t know yet …)
  • our VI environment is getting more and more acceptance (even if you hear some complaints now and then, like “awww, damn that crap my 4GiB RAM, 2×3.0GHz Windows 2008 is running soooo choppy” – simple answer, don’t use Windows Server 2008 and/or Windows Vista!)
  • I finished prepping our VM templates (at least the Windows ones)
  • we’re still putting together the plans on whether or not invest into a VDI solution.

The next few weeks are gonna be as frantic as the weeks before, I still have to migrate a lot of TYPO3 installations to our new cluster (which sadly needs time, as we need to wait for DNS changes to propagate). Honestly, I might be ending up extending the SAN volume for the MySQL data storage, as even with only three somewhat busy sites, the binary log of the last 5 days is about 2GiB in size. And we still have ~20 other busy sites on a separate box.

Lucky me, I created the MySQL data storage on a logical volume, so I can easily extend the volume in the san-manager semi-online (the fs needs to be unmounted and thus the MySQL process), then extend the physical volume (LVM2 PV) and the logical volume (LV) afterwards, and at last the underlying EXT3 file system.

As some of you know by now, I am on extended leave for now. I don’t have tree access (at my own request), though I’m gonna try to keep up with Chris and 2008.0 … So long!

TYPO3 and MySQL replication

Apparently the TYPO3 version we are using, doesn’t play too nice with the MySQL MasterMaster replication.

Sometimes, something like this is going to happen:

Well, as you can see from the last line in the log, the Slave-SQL thread found a duplicate entry and thought it is smart to just turn off the thread instead of disregarding the just made entry. So from now on, both databases drift since there ain’t no replication anymore until someone kick starts the replication again (someone being me).

Anyway, I think I finally traced the fucker down, supposedly one of the problematic cases is located in t3lib/class.t3lib_tstemplate.php on line 362.

Basically what TYPO3 is doing is a DELETE and an INSERT right afterwards. But apparently, it doesn’t check whether the DELETE even succeeded. I hacked it for now, simply adding this:

Sadly, this looks more and more like a race-condition between the two boxes (as in the replication / UPDATE being too slow), when users visit a edited site, that hasn’t had it’s cache regenerated yet. Problem is, it ain’t just this single spot, but also the search indexing, image cache and the whole page cache. For now we switched the cluster to active/passive load balancing, till we have a chance to see if a newer TYPO3 fixes those issues.

Bitching

Once again, I’m compelled to play (other call it administering :P) with our TYPO3 cluster (which is sadly running SLES).

One thing I just learned about SLES (for the ones curious, its Novell’s SuSE Linux Enterprise Server and yes, it suffers the same pain as SuSE/openSuSE). They split one single config file (at least the apache2 one) into 9 (or more) different files.

Another thing is, for what the hell does a simple LAMP need a full blown Xorg w/ KDE installed ?

Good lord! Praise the USE-flags (f.e. -X or -kde)