No-one seems to have addressed one of the main issues: why should JMeter use JDBC pooling at all?
JMeter threads generally represent independent users. Would such users share a JDBC pool? Isn't any pooling likely to be done by the server anyway? If pooling is supposed to be done by the client(s) - i.e. JMeter - then surely the implementation should be configurable? Otherwise JMeter is making the choice for the user. On 9 January 2014 07:11, Antonio Gomes Rodrigues <ra0...@gmail.com> wrote: > 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. >>
