[rsyslog] How to test rsyslog performance

[david at lang.hm]

On Mon, 29 Jun 2009, Sayan Chowdhury wrote:

> Hi,
> I saw the announcement of the 4.2.0 stable version of rsyslog. I was
> wondering if there is a way I can test the performance of rsyslog with my
> own rsyslog.conf.
> The way I am trying to use rsyslog is on a local system, which has following
> rules
>
> logging different facilities to different files with different formats.
> forwarding certain facilities to an external server.
> receive messages from one(and only one) other machine over udp.
>
> Are there any tool/scripts available which I can use to perform the tests
> myself?
> Basically what I am thinking of is running a script which writes is bunch of
> messages to syslog, but then how do I make sure all those messages were
> actually logged and not lost? It may be very painful to look through the
> entire log file 1 message at a time :)
> Is there a stat/counter based api which shows me how many messages were
> logged?

what I do is to send a known quantity of messages and include a identifier 
string in the message ('rsyslog-test-message' for example), and then grep 
the resulting files to make sure that the right number of messages arrive.

to send messages to rsyslog I have used tcpreplay to replay UDP messages. 
I first setup a system to send the messages via UDP, start tcpdump, send 
the messages to the local box (which then sends them via UDP to a remote 
server), then I stop tcpdump and can use the resulting capture file with 
tcpreplay to replay the messages at different speeds.

David Lang