[jira] Commented: (VELOCITY-595) ResourceManagerImpl.getResource() causes locking issues

> ResourceManagerImpl.getResource() causes locking issues
> -------------------------------------------------------
>
>                 Key: VELOCITY-595
>                 URL: https://issues.apache.org/jira/browse/VELOCITY-595
>             Project: Velocity
>          Issue Type: Bug
>          Components: Engine
>    Affects Versions: 1.5
>         Environment: jdk 1.5
>            Reporter: Allen Gilliland
>
> The ResourceManagerImpl.getResource() method is synchronized, which makes it difficult to share a Velocity Runtime between threads in an environment such as a j2ee web application.
> After upgrading Velocity to version 1.5 in Roller and running some performance tests I saw a very noticeable decrease in throughput for the application.  I fired up jconsole and noticed that almost all of my app server threads were in a BLOCKED state and were waiting on the ResourceManagerImpl.getResource() method.
> In my particular case the difference resulted in a loss of 2/3 of my original ops/sec, which is pretty huge.  After simply switching Velocity back to the 1.4 release and rerunning the test I saw the results I expected.
> I assume this is overactive use of Java synchronization because the developer guide suggests that the singleton model is "very appropriate model for use in a Servlet 2.2+ compliant web application".