drill-issues mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "ASF GitHub Bot (JIRA)" <j...@apache.org>
Subject [jira] [Commented] (DRILL-5874) NPE in AnonWebUserConnection.cleanupSession()
Date Mon, 16 Oct 2017 18:33:01 GMT

    [ https://issues.apache.org/jira/browse/DRILL-5874?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16206365#comment-16206365
] 

ASF GitHub Bot commented on DRILL-5874:
---------------------------------------

Github user paul-rogers commented on a diff in the pull request:

    https://github.com/apache/drill/pull/993#discussion_r144928933
  
    --- Diff: exec/java-exec/src/main/java/org/apache/drill/exec/server/rest/DrillRestServer.java
---
    @@ -204,9 +217,15 @@ public WebUserConnection provide() {
                     config.getLong(ExecConstants.HTTP_SESSION_MEMORY_RESERVATION),
                     config.getLong(ExecConstants.HTTP_SESSION_MEMORY_MAXIMUM));
     
    +        // Create a dummy close future which is needed by Foreman only. Foreman uses
this future to add a close
    +        // listener to known about channel close event from underlying layer. We use
this future to notify Foreman
    +        // listeners when the Web connection between Web Client and WebServer is closed.
This will help Foreman to cancel
    +        // all the running queries for this Web Client.
    --- End diff --
    
    Classic Web communication is connectionless and stateless. For performance, some browsers
use a keep-alive mechanism. But, this must be entirely optional. In this way, an HTTP connection
is completely unlike an RPC connection.
    
    Given that the HTTP connection will be immediately closed after submitting a query, do
we really want to kill the query in response?
    
    Or, are we using a web session concept that "closes" in response to a session timeout?


> NPE in AnonWebUserConnection.cleanupSession()
> ---------------------------------------------
>
>                 Key: DRILL-5874
>                 URL: https://issues.apache.org/jira/browse/DRILL-5874
>             Project: Apache Drill
>          Issue Type: Bug
>    Affects Versions: 1.12.0
>            Reporter: Paul Rogers
>            Assignee: Sorabh Hamirwasia
>             Fix For: 1.12.0
>
>
> When debugging another issue, I tried to use the Web UI to run the example query:
> {code}
> SELECT * FROM cp.`employee.json` LIMIT 20
> {code}
> The query failed with this error:
> {noformat}
> Query Failed: An Error Occurred
> java.lang.NullPointerException
> {noformat}
> No stack trace was provided in the log, even at DEBUG level.
> Debugging, the problem appears to be deep inside {{AnonWebUserConnection.cleanupSession()}}:
> {code}
> package io.netty.channel;
> public class DefaultChannelPromise ...
>     protected EventExecutor executor() {
>         EventExecutor e = super.executor();
>         if (e == null) {
>             return channel().eventLoop();
>         } else {
>             return e;
>         }
>     }
> {code}
> In the above, {{channel()}} is null. the {{channel}} field is also null.
> This may indicate that some part of the Web UI was not set up correctly. This is a recent
change, as this code worked several days ago.



--
This message was sent by Atlassian JIRA
(v6.4.14#64029)

Mime
View raw message