[HBASE-13555] StackServlet produces 500 error

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.0.0
• Fix Version/s: 1.1.0, 1.0.2, 2.0.0
• Hadoop Flags: Reviewed
• Assignee: Ted Yu
• Reporter: Ted Yu
• Created: 24/Apr/15 16:27
• Updated: 04/Jul/15 12:43
• Resolved: 25/Apr/15 01:33

Description

Kent Baxley reported that accessing /stacks servlet gives 500 error code.
Here is related stack trace:

2015-04-24 15:50:17,762 ERROR [789466850@qtp-2077292073-18] mortbay.log: /stacks
java.lang.IllegalStateException: WRITER
        at org.mortbay.jetty.Response.getOutputStream(Response.java:594)
        at org.apache.hadoop.hbase.http.HttpServer$StackServlet.doGet(HttpServer.java:1217)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
        at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1221)
        at org.apache.hadoop.hbase.http.lib.StaticUserWebFilter$StaticUserFilter.doFilter(StaticUserWebFilter.java:113)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.apache.hadoop.hbase.http.HttpServer$QuotingInputFilter.doFilter(HttpServer.java:1351)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.apache.hadoop.hbase.http.NoCacheFilter.doFilter(NoCacheFilter.java:49)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.apache.hadoop.hbase.http.NoCacheFilter.doFilter(NoCacheFilter.java:49)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:767)
        at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
        at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
        at org.mortbay.jetty.Server.handle(Server.java:326)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)
        at org.mortbay.jetty.HttpConnection$RequestHandler.headerComplete(HttpConnection.java:928)
        at org.mortbay.jetty.HttpParser.parseNext(HttpParser.java:549)
        at org.mortbay.jetty.HttpParser.parseAvailable(HttpParser.java:212)
        at org.mortbay.jetty.HttpConnection.handle(HttpConnection.java:404)
        at org.mortbay.io.nio.SelectChannelEndPoint.run(SelectChannelEndPoint.java:410)
        at org.mortbay.thread.QueuedThreadPool$PoolThread.run(QueuedThreadPool.java:582)

While investigating this issue, I found that /dump servlet on master (which contains stack trace) leaves the following NPE in master log:

2015-04-24 15:58:53,896 ERROR [2078627178@qtp-2077292073-24] mortbay.log: /dump
java.lang.NullPointerException
        at org.apache.hadoop.hbase.regionserver.RSDumpServlet.dumpQueue(RSDumpServlet.java:106)
        at org.apache.hadoop.hbase.master.MasterDumpServlet.doGet(MasterDumpServlet.java:105)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:707)
        at javax.servlet.http.HttpServlet.service(HttpServlet.java:820)
        at org.mortbay.jetty.servlet.ServletHolder.handle(ServletHolder.java:511)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1221)
        at org.apache.hadoop.hbase.http.lib.StaticUserWebFilter$StaticUserFilter.doFilter(StaticUserWebFilter.java:113)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.apache.hadoop.hbase.http.HttpServer$QuotingInputFilter.doFilter(HttpServer.java:1351)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.apache.hadoop.hbase.http.NoCacheFilter.doFilter(NoCacheFilter.java:49)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.apache.hadoop.hbase.http.NoCacheFilter.doFilter(NoCacheFilter.java:49)
        at org.mortbay.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1212)
        at org.mortbay.jetty.servlet.ServletHandler.handle(ServletHandler.java:399)
        at org.mortbay.jetty.security.SecurityHandler.handle(SecurityHandler.java:216)
        at org.mortbay.jetty.servlet.SessionHandler.handle(SessionHandler.java:182)
        at org.mortbay.jetty.handler.ContextHandler.handle(ContextHandler.java:767)
        at org.mortbay.jetty.webapp.WebAppContext.handle(WebAppContext.java:450)
        at org.mortbay.jetty.handler.ContextHandlerCollection.handle(ContextHandlerCollection.java:230)
        at org.mortbay.jetty.handler.HandlerWrapper.handle(HandlerWrapper.java:152)
        at org.mortbay.jetty.Server.handle(Server.java:326)
        at org.mortbay.jetty.HttpConnection.handleRequest(HttpConnection.java:542)