NullPointerException in org.eclipse.jetty.servlet.ServletHandler

[Ran Tavory]

Hi all,

Sometimes I see this "warning" in the logs (although by the sound of it it should be an error)

It looks like an internal error, not sure what's causing it or how to stop it. Any insights would be highly appreciated. (is it indeed just a "warning"?)

Thanks!

WARN  [2014-09-11 16:25:57,989] org.eclipse.jetty.servlet.ServletHandler: /pixel.gif/

! java.lang.NullPointerException: null

! at java.util.LinkedList$ListItr.next(LinkedList.java:891) ~[na:1.7.0_55]

! at com.sun.jersey.spi.container.servlet.WebComponent$Writer.writeHeaders(WebComponent.java:339) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.servlet.WebComponent$Writer.writeStatusAndHeaders(WebComponent.java:328) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.servlet.WebComponent$Writer.initiate(WebComponent.java:319) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.servlet.WebComponent$Writer.write(WebComponent.java:291) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.ContainerResponse$CommittingOutputStream.write(ContainerResponse.java:129) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.core.impl.provider.entity.ByteArrayProvider.writeTo(ByteArrayProvider.java:95) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.core.impl.provider.entity.ByteArrayProvider.writeTo(ByteArrayProvider.java:59) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.ContainerResponse.write(ContainerResponse.java:302) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.server.impl.application.WebApplicationImpl._handleRequest(WebApplicationImpl.java:1510) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1419) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.server.impl.application.WebApplicationImpl.handleRequest(WebApplicationImpl.java:1409) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.servlet.WebComponent.service(WebComponent.java:409) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:540) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.sun.jersey.spi.container.servlet.ServletContainer.service(ServletContainer.java:715) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at javax.servlet.http.HttpServlet.service(HttpServlet.java:848) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at io.dropwizard.jetty.NonblockingServletHolder.handle(NonblockingServletHolder.java:49) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1515) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.servlets.UserAgentFilter.doFilter(UserAgentFilter.java:83) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.servlets.GzipFilter.doFilter(GzipFilter.java:348) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at io.dropwizard.jetty.BiDiGzipFilter.doFilter(BiDiGzipFilter.java:127) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1486) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at io.dropwizard.servlets.ThreadNameFilter.doFilter(ThreadNameFilter.java:29) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.servlet.ServletHandler$CachedChain.doFilter(ServletHandler.java:1486) ~[gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.servlet.ServletHandler.doHandle(ServletHandler.java:519) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.handler.ContextHandler.doHandle(ContextHandler.java:1097) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.servlet.ServletHandler.doScope(ServletHandler.java:448) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.handler.ContextHandler.doScope(ContextHandler.java:1031) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.handler.ScopedHandler.handle(ScopedHandler.java:136) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at com.codahale.metrics.jetty9.InstrumentedHandler.handle(InstrumentedHandler.java:173) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at io.dropwizard.jetty.RoutingHandler.handle(RoutingHandler.java:51) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.handler.StatisticsHandler.handle(StatisticsHandler.java:162) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.handler.HandlerWrapper.handle(HandlerWrapper.java:97) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.Server.handle(Server.java:446) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.HttpChannel.handle(HttpChannel.java:271) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.server.HttpConnection.onFillable(HttpConnection.java:246) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.io.AbstractConnection$ReadCallback.run(AbstractConnection.java:358) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.util.thread.QueuedThreadPool.runJob(QueuedThreadPool.java:601) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at org.eclipse.jetty.util.thread.QueuedThreadPool$3.run(QueuedThreadPool.java:532) [gateway-collector-183d874.jar:1.0-BETA-SNAPSHOT]

! at java.lang.Thread.run(Thread.java:744) [na:1.7.0_55] 

[Ran Tavory]

Hi all, this problem escalates. 

What seemed to be as benign warning before is now completely preventing my server from functioning. 

The situation does not repro very easily, but sometimes the server stops serving requests and all I can see in the log is this series of warnings. (this time, without even a stack trace...)

I don't know whether they are the cause or the result, but that's the only evidence I've got. 

WARN [2014-09-17 10:42:17,116] org.eclipse.jetty.servlet.ServletHandler: /pixel.gif
! java.lang.NullPointerException: null
WARN [2014-09-17 10:42:17,116] org.eclipse.jetty.servlet.ServletHandler: /pixel.gif
! java.lang.NullPointerException: null
WARN [2014-09-17 10:42:17,117] org.eclipse.jetty.servlet.ServletHandler: /pixel.gif/
! java.lang.NullPointerException: null
etc...

Did anybody see this before or knows what could be the cause? 

When this happens the server returns 500 for all requests :(

thanks!

[Lance N.]

Check your versions for everything. The maven 'enforcer' plugin can help you with this. Also make sure there's only version of each package. And try running without shading the jars. After that, I would pull the source for all this stuff and single-step it. 

[Ran Tavory]

Thanks Lance I'll try that.

--
You received this message because you are subscribed to a topic in the Google Groups "dropwizard-user" group.
To unsubscribe from this topic, visit https://groups.google.com/d/topic/dropwizard-user/xQZxPfjz6eI/unsubscribe.
To unsubscribe from this group and all its topics, send an email to dropwizard-us...@googlegroups.com.
For more options, visit https://groups.google.com/d/optout.