When I installed HDFSViewer and restart web server then 404 come up!

[heavencoder]

Hey guys,

I installed hdfs viewer plugin on web server by putting a azkaban-hdfs-viewer-3.0.0 into azkaban-web-server/plugins/viewer directory, and config the plugin.properties with the following configuration:
viewer.name=HDFS
viewer.path=azkaban-hdfs-viewer-3.0.0
viewer.order=1
viewer.hidden=false
viewer.external.classpaths=extlib/commons-cli-1.2.jar,extlib/hadoop-auth-2.7.2.jar,extlib/hadoop-common-2.7.2.jar,extlib/hadoop-hdfs-2.7.2.jar,extlib/protobuf-java-2.5.0.jar
viewer.servlet.class=azkaban.viewer.hdfs.HdfsBrowserServlet
hadoop.security.manager.class=azkaban.security.HadoopSecurityManager_H_2_0
azkaban.should.proxy=false
proxy.user=azkaban
proxy.keytab.location=
allow.group.proxy=false
file.max.lines=1000

When I restart web server, and then enter the url to the login page , it came up 404.
If I remove this plugin, the login page would come up correctly.
By the way, there wasn't any other error message on log file, except for this :
2017-03-08 17:25:09 ERROR StdOutErrRedirect:55 - SLF4J: Failed to load class "org.slf4j.impl.StaticLoggerBinder".
2017-03-08 17:25:09 ERROR StdOutErrRedirect:55 - SLF4J: Defaulting to no-operation (NOP) logger implementation
2017-03-08 17:25:09 ERROR StdOutErrRedirect:55 - SLF4J: See http://www.slf4j.org/codes.html#StaticLoggerBinder for further details