Start » History » Revision 5
Revision 4 (icy, 2011-10-15 19:36) → Revision 5/10 (stbuehler, 2012-06-03 19:36)
h1. weighttp
h2. About
@weighttp@ (pronounced @weighty@) is a lightweight and small benchmarking tool for webservers.
It was designed to be very fast and easy to use and only supports a tiny fraction of the HTTP protocol in order to be lean and simple.
@weighttp@ supports multithreading to make good use of modern CPUs with multiple cores as well as asynchronous i/o
for concurrent requests within a single thread.
For event handling, weighty relies on "libev":http://software.schmorp.de/pkg/libev.html which fits the design perfectly, being lightweight and fast itself.
Thanks to that, weighty supports all modern high-performance event interfaces like epoll or kqueue, that the major OSs provide.
h2. Deployment
h3. Obtaining
Use "git":http://git-scm.com/ to fetch the latest source:
<pre>
$ git clone git://git.lighttpd.net/weighttp
</pre>
or download a .tar.gz from http://cgit.lighttpd.net/weighttp/snapshot/weighttp-master.tar.gz
h3. Bulding
Use "waf":http://code.google.com/p/waf/ (included, needs python) to build:
<pre>
$ ./waf configure
$ ./waf build
</pre>
(If you have libraries/includes in special paths, try something like this: @LINKFLAGS=-L/opt/local/lib CFLAGS=-I/opt/local/include ./waf configure@)
See ./waf --help for available configure options and other commands available.
Alternatively, you can just use gcc directly too (but you will have to (un)install it manually:
<pre>
$ gcc -g2 -O2 src/*.c -o weighttp -lev -lpthread
</pre>
h3. Installing
Depending on your configure arguments, you might need root to (un)install.
<pre>
$ ./waf install
</pre>
h3. Removing
<pre>
$ ./waf uninstall
</pre>
h2. Usage
@weighttp@ uses similar commandline arguments as @apache bench@ (ab):
<pre>
weighttp <options> <url>
-n num number of requests (mandatory)
-t num threadcount (default: 1)
-c num concurrent clients (default: 1)
-k keep alive (default: no)
-h show help and exit
-v show version and exit
</pre>
h2. Troubleshooting
Benchmarking a webserver can result in a lot of sockets being created, especially if you don't use the -k parameter to reuse existing connections.
This can cause your system to run out of TCP port numbers and you will see the following error:
<pre>
error: connect() failed: Cannot assign requested address (99)
</pre>
Linux has a hardcoded 60 seconds timeout before it reuses a previously in use port. You can mitigate the problem by tuning 2 kernel parameters:
h3. TCP_TW_REUSE
This allows reusing of sockets which are in the TIME_WAIT state when it is safe from a protocol perspectiv.
<pre>
echo 1 > /proc/sys/net/ipv4/tcp_tw_reuse
</pre>
or add "net.ipv4.tcp_tw_reuse = 1" to your /etc/sysctl.conf to make the change permanent. You need to reload it via _sysctl /etc/sysctl.conf_
h3. TCP_TW_RECYCLE
This allows fast recycling of sockets which are in the TIME_WAIT state even if it is _not safe_ from a protocol perspective.
You should not use this in a production environment. It can cause issues with loadbalancers and other mayhem.
<pre>
echo 1 > /proc/sys/net/ipv4/tcp_tw_recycle
</pre>
or add "net.ipv4.tcp_tw_recycle = 1" to your /etc/sysctl.conf to make the change permanent (bad idea). You need to reload it via _sysctl /etc/sysctl.conf_