[
https://issues.apache.org/jira/browse/HDFS-481?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=12746977#action_12746977
]
zhiyong zhang commented on HDFS-481:
------------------------------------
Hi Chris, thanks for the comment.
right, that piece of code is to prevent the forwarding servlet from passing
requests to itself. That happens if the forwarding servlet could not find the
matching servlet to forward request to.
For instance, if the user request path is /hadoop20 and hadoop20.war does not
exist under the same webapps/ folder as the ROOT.war, what the forwarding
servlet will do (through ServletContext.getContext()) in this case is to match
the longest path. Since it could not find /hadoop20, it will match against its
parent path /, which matches to ROOT.war, the forwarding servlet itself, then
it causes an infinite loop, finally causing java.lang.StackOverflowError to be
thrown.
I've thought of using logic
curContext.getServletContextName().equals(dstContext.getServletContextName())
to tell, but it will break the unit test. Since cactus unit test framework
won't be able to do cross context forwarding at this stage yet. All forwarding
occurs in the same context. In that case, ServletContext.getContext() would
always return the same context. the unit test would stuck there.
I couldn't think any other ways to work around this at this stage. Do you have
any better ideas?
Thanks.
> Bug Fixes
> ---------
>
> Key: HDFS-481
> URL: https://issues.apache.org/jira/browse/HDFS-481
> Project: Hadoop HDFS
> Issue Type: Bug
> Components: contrib/hdfsproxy
> Affects Versions: 0.21.0
> Reporter: zhiyong zhang
> Assignee: zhiyong zhang
> Attachments: HDFS-481.patch, HDFS-481.patch, HDFS-481.patch,
> HDFS-481.patch
>
>
> 1. hadoop-version is not recognized if run ant command from src/contrib/ or
> from src/contrib/hdfsproxy
> If running ant command from $HADOOP_HDFS_HOME, hadoop-version will be passed
> to contrib's build through subant. But if running from src/contrib or
> src/contrib/hdfsproxy, the hadoop-version will not be recognized.
> 2. ssl.client.do.not.authenticate.server setting can only be set by hdfs's
> configuration files, need to move this setting to ssl-client.xml.
> 3. Solve some race conditions for LdapIpDirFilter.java. (userId, groupName,
> and paths need to be moved to doFilter() instead of as class members
> 4. Addressed the following StackOverflowError.
> ERROR [org.apache.catalina.core.ContainerBase.[Catalina].[localh
> ost].[/].[proxyForward]] Servlet.service() for servlet proxyForward threw
> exception
> java.lang.StackOverflowError
> at
> org.apache.catalina.core.ApplicationHttpRequest.getAttribute(ApplicationHttpR
> equest.java:229)
> This is due to when the target war (/target.war) does not exist, the
> forwarding war will forward to its parent context path /, which defines the
> forwarding war itself. This cause infinite loop. Added "HDFS Proxy
> Forward".equals(dstContext.getServletContextName() in the if logic to break
> the loop.
--
This message is automatically generated by JIRA.
-
You can reply to this email to add a comment to the issue online.
