Personally I've found that using query timing + log aggregation on the client side is more effective than trying to mess with tracing probability in order to find a single query which has recently become a problem. I recommend wrapping your session with something that can automatically log the statement on a slow query, then use tracing to identify exactly what happened. This way finding your problem is not a matter of chance.
On Fri Nov 07 2014 at 9:41:38 AM Chris Lohfink <clohfin...@gmail.com> wrote: > It saves a lot of information for each request thats traced so there is > significant overhead. If you start at a low probability and move it up > based on the load impact it will provide a lot of insight and you can > control the cost. > > --- > Chris Lohfink > > On Fri, Nov 7, 2014 at 11:35 AM, Jimmy Lin <y2klyf+w...@gmail.com> wrote: > >> is there any significant performance penalty if one turn on Cassandra >> query tracing, through DataStax java driver (say, per every query request >> of some trouble query)? >> >> More sampling seems better but then doing so may also slow down the >> system in some other ways? >> >> thanks >> >> >> >
