Currently we speak a lot about performance of the ownCloud WebDAV server. Speaking with a computer programmer about performance is like speaking with a doctor about pain. It needs to be qualified, the pain, and also the performance concerns.
To do a step into that direction, here is a little script collection for you to play with if you like: the DAV torture collection. We started it quite some time ago but never really introduced it. It is still very rough.
What it does
The first idea is that we need a reproducable set of files to test the server with. We don’t want to send around huge tarballs with files, so Danimo invented two perl scripts called torture_gen_layout.pl and torture_create_files.pl. With torture_gen_layout.pl one can create a file that contains the layout of the test file tree, a so called layout( or .lay)-file. The .lay-file describes the test file tree completely, with names, structure and size.
torture_gen_layout.pl takes the .lay-file and really creates the file tree on a machine. The cool thing about is that we can commit on a .lay-file as our standard test tree and just pass a file around with a couple of kbytes size that describes the tree.
Now that there is a standard file tree to test with, I wrote a little script called dav_torture.pl. It copies the whole tree described by a .lay file and created on the local file system to an ownCloud WebDAV server using PUT requests. Along with that, it produces performance relevant output.
Try it
Download the tarball and unpack it, or clone it from github.
After having installed a couple of perl deps (probably only modules Data::Random::WordList, HTTP::DAV, HTTP::Request::Common are not in perl’s core) you should be able to run the scripts from within the directory.
First, you need to create a config file. For that, copy t1.cfg.in to t1.cfg (don’t ask about the name) and edit it. For this example, we only need user, passwd and url to access ownCloud. Be careful with the syntax, it gets sourced into a perl script.
Now, create the local reference tree with a .lay-file which I put into the tarball: ./torture_create_files.pl small.lay tree This command will build the file tree described by small.lay into the directory called tree.
Now, you can already treat your server: Call ./dav_torture.pl small.lay tree This will perform PUT commands to the WebDAV server and output some useful information. It also appends to two files results.dat and puts.tsv. results.dat just logs the results of subseqent call. The tsv file is the data file for the html file index.html in the same directory. That opened in a browser gives a curve over the average transmission rate of all subsequent runs of dav_torture.pl (You have run dav_torture.pl a couple of times to make that visible). The dav_torture.pl script can now be hooked into our Jenkins CI and performed after every server checkin. The resulting curve must never raise :-)
To create your own .lay-file, open torture_gen_layout.pl and play with the variables on top of the script. Simply call the script and redirect into a file to create a .lay-file.
All this is pretty experimental, but I thought it will help us to get to a more objective discussion about performance. I wanted to open this up in a pretty early stage because I am hoping that this might be interesting for somebody of you: Treat your own server, create interesting .lay files or improve the script set (testing plain PUTs is rather boring) or the result html presentation.
What do you think?