[solved] mysql on a slug - is this a bad idea?

[bernied]

I'm running gentoo on a LinkSys NSLU-2 (slug), using the armeb-softfloat-linux-uclibc stage 3. I'd like to get torrentflux, which is a php web frontend for bittorrent, but it needs mysql among other things (like Apache).

So, is installing mysql on a 266MHz, 32M ram machine, a bad idea? Likewise for Apache? I only ask because mysql has taken over 12 hours compiling time so far, and doesn't look like it's going to finish any time soon. And then there is Apache to install, and the php module for it. All dependencies seem to be available (ie. not masked, like a lot of the stuff I've tried), so there are no *obvious* (to me anyway) difficulties ahead.

Does this stuff run well on low-spec machines? Or will it run the CPU at 100% 24/7 and cook the poor little beast into an early grave?

I've been running bittorrent-curses in screen, and accessing it through ssh, and each instance of bittorrent uses about 10% CPU when steaming along, so couldn't be happier with that, but I want something a bit more accessible for the less technnically-minded on the network. Is there a lighter way to have the pretty interface?

[zeonglow]

You could try cross-compliling on a newer machine and then copying the binaries, might save you some time! You'd better check the mysql web site to see if the ram is sufficent.

[bernied]

If anyone is following this, the mysql website doesn't seem to have any minimum RAM requirements, but does suggest that each instance of mysql will use about 100M of RAM, which doesn't sound good for a 32M machine, hmmmm?

I interrupted the build twice, once because it just seemed too slow (over 48 hours for one package?), and once because I thought the machine had hung. What seems to be happening is that the 32M ram is nowhere near enough for the compiling, and in top what I see is usb-storage and kswapd0 both very busy, cc1plus using all the memory, and around 65% of cpu time is waiting (that is what 'wa' means, right?). So it's swapping madly and only compiling at maybe 10% of cpu time, which is pretty slow on a 266MHz machine. I will give it a few days this time and see what happens.

Apache is running ok though. Only mysql and mod-php to add to get torrentflux going. The torrentflux docs suggest that another database solution might be used, but the details are hazy, so I'm still going to try this.

EDIT: just had a look at the ipkg lists for uNSLUng (my other slug runs on this), and they do include mysql, apache, apache-php, which is encouraging.

[tokka]

[bernied]

It almost works. All the components work on the uNSLUng machine, but when I try to do stuff with the php scripts (like running torrentflux), apache hangs - I can't reach the webserver at all until I restart it, and no error messages. Most of the httpd processes reported in top (atop on this machine) disappear and those remaining need kill -9 to die. A simple php script (the old phpinfo) works fine.

mysql has finished building on the gentoo box, emerging php now.

I think it might all be a bit of wasted effort though - not optimistic that this lot will fly.

[bernied]

Well, I'm mightily impressed - the slug is badly named, unless there is a flying slug.

So, using gentoo it all works very well - I now I have a fanless, web-based bittorrent server running.
Torrentflux is very attractive and seems quite sensible/friendly/intuitive etc (all the good things a GUI should be). The bittorrent client runs in python, the web-side is php and it uses mysql to keep its data.

Total CPU usage varies, but for one torrent (which is about all I ever have going at a time), it's about 20-35% when the web interface isn't running, another 10% or so when it's being watched. There's a lot of memory-hungry stuff involved (mysql, apache2, python), and it's using about 40M of swap on top of the 32M of RAM. This seriously makes me want to 'fatten' this slug (doubling RAM to 64M - involves soldering - ouch!)
[EDIT: CPU usage is more like 5-25%, once it settles down, but this torrent is not very fast - 10K or so]

Here's some example output from top - any suggestions on how to reduce overhead (memory and cpu) appreciated - this is inside a firewall and I don't plan to open the web server to the big wide world, so security not a huge factor (I am running it all under a user that cannot do anything else though)...

this output is from when I am using the web front-end, so it's a bit busier than when I'm not watching:

[bxwen]

I have torrentflux working also. But mysqld prevents my hard drive spinning down.