performance


smokeping and SOAP

We’ve had an issue with performance of a SOAP interface, and here’s how you go about setting up smokeping to time it:- extraargs = -H Content-Type:text/xml --data @/srv/scripts/soap_check/soap-test.xml urlformat = http://server.name.com/url/soap_url The only annoying problem is that the SOAP payload cannot be included as part of the command line, so any slaves would require the file manually copied into the same location

Filesystem caching and performance

well this is slightly surprising, but in a very good way, and does lead to some interesting suggestions on how to best to improve matters, but look at the following graph of FAST ESP query latency: Notice that the average latency drops as we use the server more … but WHY? Well that’s just because we’re running the FAST indexes on a ZFS based file system and the L2 ARC cache is making it’s presence felt

playing with TCP Trace

# tcpdump -ni en0 port 80 -w output.trace # tcptrace -G output.trace # xplot *tput.xpl From the online manpage: Yellow: instantaneous packets Red: Throughput for the last few packets Blue: Throughput since the start of the stream/connection Other useful graphs: _owin.xpl - outstanding data/congestion _rtt.xpl - round trip time/time _ssize.xpl - segment size/time _tput.xpl - throughput/time _tsg.xpl - time sequence graph _tline.xpl - Timeline graph - W Richard Stevens style Just some notes here so I don’t forget the basics - manual over at here