Thanks Ilya, Rafael and Khosrow for your feedback.
I think having the option to select between connection pools can be useful when experimenting DB issues and need troubleshooting. However, as an admin I would expect the connection pool decision to be made by CloudStack internally. Upgrading to DBCP 2.x seems reasonable, DBCP 1.4 is compiled using Java 6 libraries and as we moved to Java 8 it would make sense to move to the newest version which runs on Java 7, following recommendations on: http://commons.apache.org/proper/commons-dbcp/ ________________________________ From: Rafael Weingärtner <rafaelweingart...@gmail.com> Sent: Thursday, March 15, 2018 8:43:12 AM To: dev Subject: Re: [DISCUSS] CloudStack Connection Pools Thanks for your feedback Ilya. I would first say that most of the problems relating database are not due to connection pool libraries, but rather to the DAO layer that is an ad-hoc implementation of JPA. Not to mention transactions being managed in a not so elegant and efficient fashion. We can for sure externalize the selection of the database connection pool, but my worry is how this will be implemented and maintained later. If it becomes a neat and nice solution, it is awesome. However, if it locks down different places in the code base, then we will have problems. If we were using a framework to manage DAO connection and transaction, it would be a matter of changing the connection pool bean, but I do not think that this is the case in ACS right now. Moreover, I have seen some of the tests between these database connection pools. There seems to be an advantage on these new ones when you have lots of idle connections, but when things start to get busy they seem to converge to similar results. Therefore, the benefits between different libraries will depend on different factors of the application. I do prefer consolidated libraries; it does not mean that it is open for debate and tests the selection of another one. I also do not see a problem that DBCP is not getting thousands of commits every day. These are all very concise libraries, it is normal to get less commit as time goes by and they stabilize. All of Apache’s commons libraries are like this. On Wed, Mar 14, 2018 at 4:17 PM, ilya musayev <ilya.mailing.li...@gmail.com> wrote: > When everything works smooth - the end user does not need to know whats > under the hood. > > However, when things begin to swing and your hands are tied to just one CP > - what do you do? > > On Wed, Mar 14, 2018 at 10:50 AM, Khosrow Moossavi <kmooss...@cloudops.com > > > wrote: > > > Why would we want to expose this choice to administrator of Cloudstack > > whose responsibility > > is to keep it running and not knowing about the inner-mechanic of how it > > works. right? It's not > > like that we're giving them a choice of which database to connect to. > > > > So on that note, I would say we need to agree on any of those CP > libraries > > and implement, the > > same way we chose for example log4j or slf4j over one another, or any > other > > _library_ we use. > > > > Khosrow Moossavi > > > > CloudOps > > > > > > > > On Wed, Mar 14, 2018 at 10:36 AM, Nicolas Vazquez < > > nicolas.vazq...@shapeblue.com> wrote: > > > > > Thanks Khosrow and Rafael. You both agree on Spring Data as the best > > > option, I see it would require a big effort and commitment to migrate > to > > > it, therefore it can take some (long) time to achieve it. > > > > > > As a more viable option, would you agree on supporting different > > > connection pool management libraries and letting the administrator > choose > > > which one to use? (DBCP 1.4 as default) > > > > > > ________________________________ > > > From: Rafael Weingärtner <rafaelweingart...@gmail.com> > > > Sent: Tuesday, March 13, 2018 8:52:50 AM > > > To: dev > > > Subject: Re: [DISCUSS] CloudStack Connection Pools > > > > > > Spring data would be awesome. It is very flexible and has a very good > > API. > > > However, this would require commitment from our side to slowly migrate > > > things to it. > > > > > > Regarding the connection pool management libraries; I would prefer > either > > > C3P0 or 2.* DBCP. The other two sound trendy, but I worry about this > type > > > of project in the long run. Both DBCP from Apache and C3P0 from > Hibernate > > > (RedHat) sound a more reasonable selection for me. They have been > around > > > for years, and have a solid community base already. > > > > > > On Mon, Mar 12, 2018 at 11:31 PM, Khosrow Moossavi < > > kmooss...@cloudops.com > > > > > > > wrote: > > > > > > > Hi Nicolas > > > > > > > > From my past experiences, I prefer 1) HikariCP 2) Tomcat Pool 3) C3P0 > > 4) > > > > DBCP in that order. Although I don't have > > > > any benchmark of my own to provide, and the ones you mentioned are > > really > > > > informative anyway. > > > > > > > > To me the broader subject is the _one_ who uses the pool, I mean if > the > > > > transactions are handled in a faster way and > > > > released sooner and with shorter locks, generally speaking if it's > more > > > > efficient, I don't think from ACS point of view > > > > there won't be much difference between the above mentioned options. > > > > > > > > On the same subject, it might be more interesting to use Spring Boot > in > > > > general and Spring Boot Data in particular > > > > rather than only changing the CP functionality, and slowly > > > refactor/retire > > > > the DAO layer in favor of Spring Boot equivalent > > > > implementation. > > > > > > > > > > > > Khosrow Moossavi > > > > > > > > CloudOps > > > > > > > > > > > > > > > > On Mon, Mar 12, 2018 at 9:32 PM, Nicolas Vazquez < > > > > nicolas.vazq...@shapeblue.com> wrote: > > > > > > > > > Hi all, > > > > > > > > > > > > > > > I would like to introduce a topic for discussion, regarding DB > > > connection > > > > > pools used in CloudStack, currently Apache Commons DBCP 1.4 ( > > > > > http://commons.apache.org/) is used. I've been investigating this Apache Commons – Apache Commons<http://commons.apache.org/> commons.apache.org Apache Commons Proper. Commons Proper is dedicated to one principal goal: creating and maintaining reusable Java components. The Commons Proper is a place ... > > > topic > > > > > as we are having complains of random issues on MySQL connection > pool > > on > > > > > large environments. Please let me know if this topic has already > been > > > > > discussed before. > > > > > > > > > > > > > > > First of all, DBCP 1.4 has been released on 2010 ( > > > > > https://commons.apache.org/proper/commons-dbcp/changes-report.html > ), > > > and > > > > > no minor/patch version has been released since then. It seems to > work > > > in > > > > > high performance with relatively low traffic and low load > > applications. > > > > > However, it is single threaded, and in order to be thread-safe, the > > > > entire > > > > > pool needs to be locked. It is also reported that an CPU and > > concurrent > > > > > threads increases, the performance gets affected. This is a serious > > > issue > > > > > on highly concurrent systems, such as CloudStack. > > > > > > > > > > > > > > > I've been investigating some options to replace it: > > > > > - The first option can be upgrading to version 2.x. Issues on > > > performance > > > > > and concurrency could be solved using this version. > > > > > - Tomcat JDBC Connection Pool. Please check: > > > https://tomcat.apache.org/ > > > > > tomcat-7.0-doc/jdbc-pool.html. > > > > > > > > > > - Other replacement options found: BoneCP, C3P0, HikariCP > > > > > > > > > > > > > > > Given these options, I've been looking for benchmarks to compare > them > > > > (*). > > > > > Looks like HikariCP (http://brettwooldridge.github.io/HikariCP/) > > could > > > > be > > > > > the best replacement, improving performance and stability. Another > > good > > > > > replacement option could be Tomcat. > > > > > > > > > > > > > > > I've been also examining the codebase, data source initialization > is > > > done > > > > > on TransactionLegacy class under the cloud-framework-db project. > > > > > Replacement work should be done on this class. Instead of pure > > > > replacement, > > > > > a global setting can be introduced to make the admins able to > select > > > > which > > > > > connection pool to use. > > > > > > > > > > What do you think? Any possitive/negative feedback is welcome as > well > > > as > > > > > new ideas. As mentioned before, I don't know if it has been > discussed > > > > > before, sorry in advance if it has. > > > > > > > > > > Kind regards, > > > > > Nicolas > > > > > > > > > > (*) Links to benchmarks and comparissons: > > > > > https://www.wix.engineering/single-post/how-many-threads- > > > > > does-it-take-to-fill-a-pool > > > > > https://www.wix.engineering/single-post/how-does-hikaricp- > > > > > compare-to-other-connection-pools > > > > > <https://www.wix.engineering/single-post/how-does-hikaricp- > > > > > compare-to-other-connection-pools>https://beansroasted. > > > > > wordpress.com/2017/07/29/connection-pool-analysis/ > > > > > https://beansroasted.wordpress.com/tag/connection-pool-comparison/ > > > > > <https://beansroasted.wordpress.com/tag/connection- > pool-comparison/> > > > > > https://github.com/brettwooldridge/HikariCP/wiki/%22My-benchmark- > > > > > doesn't-show-a-difference.%22 > > > > > http://www.trustiv.co.uk/2014/06/battle-connection-pools > > > > > > > > > > nicolas.vazq...@shapeblue.com > > > > > www.shapeblue.com<http://www.shapeblue.com> > > > > > , > > > > > @shapeblue > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- > > > Rafael Weingärtner > > > > > > nicolas.vazq...@shapeblue.com > > > www.shapeblue.com<http://www.shapeblue.com> > > > , > > > @shapeblue > > > > > > > > > > > > > > > -- Rafael Weingärtner nicolas.vazq...@shapeblue.com www.shapeblue.com , @shapeblue
