I should stress that we only cache `isTraceEnabled()` in a static field. Debug logging can still be enabled or disabled on the fly.
Cheers Dan On Fri, Sep 30, 2016 at 3:14 PM, Wolf Fink <wf...@redhat.com> wrote: > Ok, > > thanks for clarifying it. > > So there is a factor of 3 for the test if no trace is enabled, just for > checking. > It makes sense to use it. > But my concern is still that it is sometimes good to have the possibility to > enable debug for some important information in production just on the fly > and switch it of to prevent from throtteling the server by that log > statements or restart the server. > We have the same issue in EAP but here a restart is not that bad as here you > don't have to load the cache or rebalance the cluster for stop/start. > > - Wolf > > On Fri, Sep 30, 2016 at 1:53 PM, David M. Lloyd <david.ll...@redhat.com> > wrote: >> >> On 09/30/2016 01:53 AM, Sebastian Laskawiec wrote: >> > Hey! >> > >> > A while ago I asked Radim and Dan about these kind of constructs [1]: >> > >> > private boolean trace = logger.isTraceEnabled(); //stored in a field >> > >> > ... called in some method ... >> > if(trace) >> > logger.tracef(...); >> > ... >> > >> > At first they seemed wrong to me, because if one changes logging level >> > (using JMX for example), the code won't notice it. I also though it's >> > quite ok to use tracef directly, because JIT will inline and optimize >> > it. >> > >> > Unfortunately my benchmarks [2] show that I was wrong. Logger#tracef >> > indeed checks if the logging level is enabled but since JBoss Logging >> > may use different backends, the check is not trivial and is not inlined >> > (at least with default settings). >> >> What backend where you using with your test? >> >> > The performance results look like this: >> > Benchmark Mode Cnt Score Error >> > Units >> > MyBenchmark.noVariable thrpt 20 *717252060.124* ± 13420522.229 >> > ops/s >> > MyBenchmark.withVariable thrpt 20 *2358360244.627* ± 50214969.572 >> > ops/s >> > >> > So if you even see a construct like this: logger.debuf or logger.tracef >> > - make sure you check if the logging level is enabled (and the check >> > result is stored in a field). >> > >> > That was a bit surprising and interesting lesson :D >> > >> > Thanks >> > Sebastian >> > >> > [1] >> > https://github.com/infinispan/infinispan/pull/4538#discussion_r80666086 >> > [2] https://github.com/slaskawi/jboss-logging-perf-test >> > >> > >> > _______________________________________________ >> > infinispan-dev mailing list >> > infinispan-dev@lists.jboss.org >> > https://lists.jboss.org/mailman/listinfo/infinispan-dev >> > >> >> -- >> - DML >> _______________________________________________ >> infinispan-dev mailing list >> infinispan-dev@lists.jboss.org >> https://lists.jboss.org/mailman/listinfo/infinispan-dev > > > > _______________________________________________ > infinispan-dev mailing list > infinispan-dev@lists.jboss.org > https://lists.jboss.org/mailman/listinfo/infinispan-dev _______________________________________________ infinispan-dev mailing list infinispan-dev@lists.jboss.org https://lists.jboss.org/mailman/listinfo/infinispan-dev
