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>
> 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
> Khosrow Moossavi
> 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
> > 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
> > 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
> > a global setting can be introduced to make the admins able to select
> > 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