Hi, I am agree with Philippe, it will be great to remove Excalibur and put tomcat pool for 2 reasons : Better performance (see http://www.tomcatexpert.com/blog/2010/03/22/understanding-jdbc-pool-performance-improvementsand http://blog.ippon.fr/2013/03/13/improving-the-performance-of-the-spring-petclinic-sample-application-part-3-of-5/ ) have something which developer know and use
Antonio 2014/1/9 sebb <seb...@gmail.com> > On 8 January 2014 23:07, Philippe Mouawad <philippe.moua...@gmail.com> > wrote: > > On Wednesday, January 8, 2014, sebb wrote: > > > >> On 8 January 2014 22:10, Philippe Mouawad <philippe.moua...@gmail.com> > >> wrote: > >> > Reopening this thread after this bug report: > >> > > >> > - https://issues.apache.org/bugzilla/show_bug.cgi?id=55977 > >> > > >> > > >> > We have 2 options to fix this bug: > >> > > >> > Option 1): > >> > > >> > Upgrade excalibur libraries to 2.1 > >> > > >> > Option 2): > >> > > >> > Switch to a new pooling implementation like Tomcat Pool (or > >> commons-dbcp) . > >> > Tomcat pool is more recent than commons-dbcp and is supposed to have > much > >> > better performances with high number of threads. > >> > > >> > It has all features currently available for excalibur. > >> > >> Not entirely true; Excalibur has quite sophisticated instrumentation > >> (logging). > >> That is how the log was generated and how the problem was found. > >> > >> > As I have said many times in the past, I personnally don't like the > fact > >> we > >> > have some (fortunately very few libraries of retired Apache project > >> > (Excalibur) and would find it great to remove all excalibur related > jars, > >> > but we didn't get a consensus on this. > >> > >> I agree that it is unfortunate that Excalibur has been retired. > >> > >> However just because Commons Pool is newer does not necessarily make > >> it significantly better. > > > > > > I fully agree with you sebb , what i said was based on analysis by tomcat > > team which I tend to trust but we could double check. > > > > I am speaking about tomcat pool vs commons-dbcp > > OK, but the same considerations apply. > > >> Have you compared performances? > > > > > > There are benchmarks between commons dbcp and tomcat-pool I remember I > read > > them, but I can't find them now. > > > > Also tomcat-pool relies on jdk5 concurrent apis. > > http://tomcat.apache.org/tomcat-7.0-doc/jdbc-pool.html > > > > I also made a comparison on a ecommerce website with the 2 pools and it > > had better behaviour. > > But commons-dbcp is a great library also. > > > > I didn't compare perfs of excalibur vs others.My concern is the > deprecation > > state. > > It's not deprecated, just unmaintained. > But if it works, don't fix it. > > > > >> This time we have an opportunity which we should maybe jump at. > >> > >> Changing to an updated version of Excalibur is trivial, and does not > >> affect users who may be relying on its instrumentation. > > > > where is the doc ? > > >> > >> Changing to use Pool instead will require quite a lot of work. > >> We may then find another implementation that is even better and have > >> to go through it all again. > > > > > > commons dbcp is quite stable and tomcat pool is not that new > > I follow the Tomcat lists and there have been some recent fairly basic > bugs reported against it. > So I'm not sure how stable it is yet. > > >> > >> So if we do change, I think we need to do it in such a way that users > >> can plug in whatever pooling implementation they want > > > > > > not sure it is worth, also the aim is to drop excalibur, if we keep it > then > > it is not worth the effort. > > The point is that any pool implementation will have its advantages and > disadvantages. > > Even if we decided to drop Excalibr, I still think it would make sense > to ensure that the pooling code is pluggable. > We don't know what pooling system users will be installing for their > systems. > > > > >> > >> We should anyway do the version update because that is trivial (and > >> easily reversible). > > > > ok > > > >> > >> > > >> > My 2cts. > >> > > >> > Regards > >> > > >> > Philippe M. > >> > > >> > > >> > > >> > > >> > On Thu, Aug 23, 2012 at 12:46 AM, sebb <seb...@gmail.com> wrote: > >> > > >> >> On 22 August 2012 21:43, Philippe Mouawad < > philippe.moua...@gmail.com> > >> >> wrote: > >> >> > On Wed, Aug 22, 2012 at 7:21 PM, sebb <seb...@gmail.com> wrote: > >> >> > > >> >> >> On 22 August 2012 17:52, Milamber <milam...@apache.org> wrote: > >> >> >> > On Wed, Aug 22, 2012 at 4:34 PM, Philippe Mouawad < > >> >> >> > philippe.moua...@gmail.com> wrote: > >> >> > >> >> <snip/> > >> >> > >> >> >> >> I think we should really remove dependency on Apache Excalibur. > >> >> >> > >> >> >> We still use parts of Excalibur for JDBC pooling. > >> >> >> > >> >> >> I don't see the point of pooling if you are testing JDBC; it then > >> >> >> becomes as much a test of the pool rather than JDBC. > >> >> >> > >> >> > Don't understand this > >> >> > >> >> JMeter threads are intended to represent independent users, so > sharing > >> >> JDBC connections between different threads is equivalent to sharing > >> >> between different users. Does not make sense to me. > >> >> > >> >> But assumijng that there is a use case for sharing a pool between > >> threads: > >> >> If a JDBC performance test shows problems - is it the JDBC database, > >> >> or the pooling implementation? > >> >> What if the pooling implementation is different from the one in the > >> >> application one is simulating? > >> >> > >> >> >> > >> >> >> If we do want to support pooling, it should be selectable. > >> >> >> However I don't know if there is a standard Pooling API, so that > >> might > >> >> >> not be possible. > >> >> >> > >> >> >> Why not use commons-dbcp or tomcat-pool for this ? > >> >> > >> >> They are just specific examples of pools; no different really from > >> >> sticking with Excalibur. > >> >> > >> >> If we truly want to allow users to test pooling, they should be able > >> >> to use any pool they wish, so they can see which one meets their > needs > >> >> best. > >> >> > >> >> But I suspect this will be quite tricky to allow arbitrary pooling > >> >> implementations. > >> >> > >> > > >> > > >> > > >> > -- > >> > Cordialement. > >> > Philippe Mouawad. > >> > > > > > > -- > > Cordialement. > > Philippe Mouawad. >
