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 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 > , > @shapeblue > > > >
