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https://issues.apache.org/jira/browse/HAMA-378?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=13025568#comment-13025568
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ChiaHung Lin edited comment on HAMA-378 at 4/27/11 2:38 AM:
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The groom server has path referred to the jar file copied it. And the jar file
exists on the groom server, but the file to be unpacked in the path is not a
correct one.
>From what has been discovered, it looks like when executing
>findContainingJar() in BSPJob, my_class.getClassLoader() would be different
>from what has been proposed in RunJar, in which the context class loader is
>set to URLClassLoader. Also, the jar file in command e.g. `hama jar
>path/to/eaxmple.jar` is added to classpath (if what perceived is correct). But
>in the findContainingJar function, the context loader is not the one proposed
>i.e. URLClassLoader; therefore, url.getProtocol() only returns `file' instead
>of `jar', resulting the execution of findContaingJar function returns null.
>Thus, bsp.jar is not set in configuration.
This is just what is discovered, but it might be a red herring and a further
investigation may be required.
was (Author: chl501):
The jar file exists on the groom server, but the file to be unpacked in the
path is not a correct one.
>From what has been discovered, it looks like when executing
>findContainingJar() in BSPJob, my_class.getClassLoader() would be different
>from what has been proposed in RunJar, in which the context class loader is
>set to URLClassLoader. Also, the jar file in command e.g. `hama jar
>path/to/eaxmple.jar` is added to classpath (if what perceived is correct). But
>in the findContainingJar function, the context loader is not the one proposed
>i.e. URLClassLoader; therefore, url.getProtocol() only returns `file' instead
>of `jar', resulting the execution of findContaingJar function returns null.
>Thus, bsp.jar is not set in configuration.
This is just what is discovered, but it might be a red herring and a further
investigation may be required.
> Lost connection to BSP Master [host/ip:port]. Retrying...
> -----------------------------------------------------------
>
> Key: HAMA-378
> URL: https://issues.apache.org/jira/browse/HAMA-378
> Project: Hama
> Issue Type: Improvement
> Components: bsp
> Reporter: ChiaHung Lin
> Priority: Minor
>
> When submitting a job, at the server side the GroomServer reports message
> Lost connection to BSP Master [host/ip:port]. Retrying...
> java.lang.NullPointerException
> This seems because the script hama only includes jar files (such as
> hama-0.3.0-examples.jar) located under basedir, the same folder as build.xml.
> Also, a quick check shows that when submitting a job, the ClassLader used is
> sun.misc.Launcher$AppClassLoader, instead of java.net.URLClassLoader. This
> might not be the root cause, but a further investigation may be required.
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