[jboss-jira] [JBoss JIRA] (WFLY-11833) Stateful Session Bean affinity URI instead of cluster

[Richard Achmatowicz (Jira)]

    [ https://issues.jboss.org/browse/WFLY-11833?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13762327#comment-13762327 ] 

Richard Achmatowicz edited comment on WFLY-11833 at 7/23/19 10:00 AM:
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To further clarify what is going on here,  let's differentiate between the calling proxy affinity and the result proxy affinity. In this example, a client makes a remote invocation on a SLSB deployed on a server using its calling proxy. The server, in the process of processing the invocation, creates a SFSB on the server, and returns a proxy for that SFSB back to the caller. This is the result proxy. During this single invocation, both the caller proxy and the result proxy will have their affinities adjusted.

The adjustment to the caller proxy is made using the information gathered by invocation interceptors, the affinity parameters passed to the server, and the affinity changes returned from the server. The final adjustments are made in EJBClientInvocationContext.getResult() when the final settings for strong affinity and weak affinity are established and used to reset the strong and weak affinity defined in the EJBInvocationHandler. The purpose of this affinity adjustment is for correctly managing the behavior of SLSB load balancing and SFSB fail-over, both of which depend on affinities to constrain choice of the correct target node, and which is largely determined by the type of bean the proxy represents and where the last invocation successfully executed.

Th adjustment to result proxy is made during the marshaling and un-marshaling of the result from the server back to the client. Here, writeReplace() and readResiove() in the ObjectResolver for the Marshaller are used to replace the original affinity defined in the created proxy from Affinity.LOCAL to something else, where that something else depends only on the connection endpoints between client and server, as mentioned above. 

It's important to keep these two aspects separated, as things can otherwise get very confusing.


was (Author: rachmato):
To further clarify what is going on here,  let's differentiate between the calling proxy affinity and the result proxy affinity. In this example, a client makes a remote invocation on a server using its calling proxy. The server, in the process of processing the invocation, creates a SFSB on the server, and returns a proxy for that SFSB back to the caller. This is the result proxy. During this single invocation, both the caller proxy and the result proxy will have their affinities adjusted.

The adjustment to the caller proxy is made using the information gathered by invocation interceptors, the affinity parameters passed to the server, and the affinity changes returned from the server. The final adjustments are made in EJBClientInvocationContext.getResult() when the final settings for strong affinity and weak affinity are established. The purpose of this affinity adjustment is for correctly managing the behavior of SLSB load balancing and SFSB fail-over, both of which depend on affinities to constrain choice of the correct target node, and which is largely determined by the type of bean the proxy represents and where the last invocation successfully executed.

Th adjustment to result proxy is made during the marshaling and un-marshaling of the result from the server back to the client. Here, writeReplace() and readResiove() in the ObjectResolver for the Marshaller are used to replace the original affinity defined in the created proxy from Affinity.LOCAL to something else, where that something else depends only on the connection endpoints between client and server, as mentioned above. 

It's important to keep these two aspects separated, as things can otherwise get very confusing.

> Stateful Session Bean affinity URI instead of cluster
> -----------------------------------------------------
>
>                 Key: WFLY-11833
>                 URL: https://issues.jboss.org/browse/WFLY-11833
>             Project: WildFly
>          Issue Type: Bug
>          Components: Clustering, EJB
>    Affects Versions: 16.0.0.Final
>         Environment: WildFly cluster having SFSB deployed.
>            Reporter: Joerg Baesner
>            Assignee: Richard Achmatowicz
>            Priority: Major
>              Labels: downstream_dependency
>         Attachments: stateful-timeout.zip, test-debug-log.txt
>
>
> Deployed is an application with the following setup:
> * Containing a SFSB (_with passivationCapable="true"_)
> * A SLSB exposing a _remote_ method to a standalone client returning an instance of the SFSB
> Scenario:
> A standalone client is invoking the _remote_ method on the Stateless Session Bean and a new instance of the Stateful Session Bean is returned.
> The issue is that the affinity of the returned Stateful Session Bean is URI instead of Cluster.
> See the attached Gradle reproducer application



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