[hibernate-issues] [Hibernate-JIRA] Commented: (HHH-7190) Cache JDBC proxy class defintions

[Steve Ebersole (JIRA)]

    [ https://hibernate.onjira.com/browse/HHH-7190?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=46053#comment-46053 ] 

Steve Ebersole commented on HHH-7190:
-------------------------------------

Current code is using {{java.lang.reflect.Proxy#newProxyInstance}}, which is a convenience method.  However, this does require calls into the synchronized method {{java.lang.reflect.Proxy#getProxyClass}} each and every time a proxy instance is generated.  In concurrent systems that sync is a potential bottleneck.  

Switching to explicitly building and holding on to the proxy class reference and then manually instantiating the proxies as needed through that class reference, rather than using the convenience method, should eliminate that bottleneck.

> Cache JDBC proxy class defintions
> ---------------------------------
>
>                 Key: HHH-7190
>                 URL: https://hibernate.onjira.com/browse/HHH-7190
>             Project: Hibernate ORM
>          Issue Type: Improvement
>          Components: core
>    Affects Versions: 4.0.1, 4.1.1
>         Environment: java version "1.6.0_23"
> Java(TM) SE Runtime Environment (build 1.6.0_23-b05)
> Java HotSpot(TM) 64-Bit Server VM (build 19.0-b09, mixed mode)
>            Reporter: Lucas POUZAC
>              Labels: performance
>         Attachments: hibernate.jpg
>
>
> After migrating our application to version 4.0.1 of hibernate, we noticed a performance degradation. (same problem with the version 4.1.1)
> Before migration, the average response time of our http request was 747ms (during load test).
> Since the migration, the average response time is greater than 1200ms (during the same load test).
> After recording the behavior of the JVM, we note that Hibernate uses methods of the java api with synchronized blocks (java.lang.reflect.Proxy.getProxyClass (...)). See attachment.

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