Playr attempts to answer the question "How much headroom will our new
server give us?"
It's a PostgreSQL log file replay application. It works by taking your
PostgreSQL logs and running them through a conversion application
which turns them into a binary format. The replay application then
reads in the binary format and attempts to replay the logs in the same
timing with the same backend assignments. By attempting to do this,
Playr is stressing a PostgreSQL box with the same query frequency
distributed across the same quantity of backends, in an attempt to
truly stress PostgreSQL in the same way as it was originally stressed
when the logs were taken.
Theoretically, using Playr in conjunction with sysstat and a graphing
application like Staplr, one can analyze other hardware against
production load.
Playr is not designed to work with lesser hardware than the machine
where the log files were originally taken from. It is not designed to
be a benchmark application in the traditional sense. If the new
hardware can not keep up with the timing, Playr will give up its
stress test and let you know that it fell behind.
More information about Playr can be found at:
https://area51.myyearbook.com/trac.cgi/wiki/Playr