I have many servlets in a web applicaton; for some stange reason, only and only one of them always fails in initialization with the following error trace:-
00000045 ServletWrappe E SRVE0100E: Did not realize init() exception thrown by servlet MyServletX: java.lang.NullPointerException
at com.ibm.ws.webcontainer.WebAppPmiListener.onServletStartInit(WebAppPmiListener.java:120)
at com.ibm.ws.webcontainer.webapp.FireOnServletStartInit.fireEvent(WebAppEventSource.java:237)
at com.ibm.ws.webcontainer.util.EventListeners.fireEvent(EventListeners.java:48)
at com.ibm.ws.webcontainer.webapp.WebAppEventSource.onServletStartInit(WebAppEventSource.java:105)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.init(ServletWrapper.java:261)
at com.ibm.ws.webcontainer.servlet.ServletWrapper.handleRequest(ServletWrapper.java:444)
at com.ibm.ws.webcontainer.webapp.WebApp.handleRequest(WebApp.java:2841)
at com.ibm.ws.webcontainer.webapp.WebGroup.handleRequest(WebGroup.java:220)
at com.ibm.ws.webcontainer.VirtualHost.handleRequest(VirtualHost.java:204)
at com.ibm.ws.webcontainer.WebContainer.handleRequest(WebContainer.java:1681)
at com.ibm.ws.webcontainer.channel.WCChannelLink.ready(WCChannelLink.java:77)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleDiscrimination(HttpInboundLink.java:421)
at com.ibm.ws.http.channel.inbound.impl.HttpInboundLink.handleNewInformation(HttpInboundLink.java:367)
at com.ibm.ws.http.channel.inbound.impl.HttpICLReadCallback.complete(HttpICLReadCallback.java:94)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.requestComplete(WorkQueueManager.java:548)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.attemptIO(WorkQueueManager.java:601)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager.workerRun(WorkQueueManager.java:934)
at com.ibm.ws.tcp.channel.impl.WorkQueueManager$Worker.run(WorkQueueManager.java:1021)
at com.ibm.ws.util.ThreadPool$Worker.run(ThreadPool.java:1332)
I could not figure out if there is anything extra ordinary with this servlet. There is no init() method in this servlet and it extends HTTPServlet. Any idea what could be reason? I am using websphere server 6.0.x. How to get more debugging information in this case?
Well I don't know still cause of above error, but this is how it started working strangely:- i) Re-applied recommended fixes by IBM for my WAS version (especially there are IBM JDK upgrade related fix patches) ii) created a new profile of server iii) Install web application to new profile and it started working.
I don't think this is a product issue.
To debug this problem what i would suggest is to place a simple servlet (kind of Hello World) and deploy it to the server and see what happens.
initialization does not necessarily mean init() method alone.
If you have a static block in your servlet, if you have any variables that are initialized they would all be part of the initialization activity.
Look at the FFDC logs that were generated when this error occurred and that should provide you with clues.
As bkail mentioned, also ensure that yo have the latest fixpacks just to eliminate known problems with the product.
if the hello world servlet works, suggest you place hte servlet code here along with the SystemOut and System Err logs that correspond to this issue along with the relevant FFDC logs and i am sure most of us will be able to help you out with this
HTH
Manglu
Related
Note: Help with the immediate problem would be great, but mostly I'm looking for advice on troubleshooting gRPC timing issues in general (this isn't my first such issue).
I am adding a new server streaming service to a C++ module which has an existing server streaming service, and the two appear to be conflicting. Specifically, the completion queue Next() call on the server is crashing intermittently after the C# client calls Cancel() on the cancellation token for one of the services. This doesn't happen if I run each service independently.
On the client, I get this at the response stream MoveNext() call:
System.InvalidOperationException
HResult=0x80131509
Message=Shutdown has already been called
Source=Grpc.Core
StackTrace:
at Grpc.Core.Internal.CompletionQueueSafeHandle.BeginOp()
at Grpc.Core.Internal.CallSafeHandle.StartReceiveMessage(IReceivedMessageCallback callback)
at Grpc.Core.Internal.AsyncCallBase`2.ReadMessageInternalAsync()
at Grpc.Core.Internal.ClientResponseStream`2.<MoveNext>d__5.MoveNext()
at System.Runtime.ExceptionServices.ExceptionDispatchInfo.Throw()
at System.Runtime.CompilerServices.TaskAwaiter.HandleNonSuccessAndDebuggerNotification(Task task)
at System.Runtime.CompilerServices.TaskAwaiter`1.GetResult()
at MyModule.Connection.<DoSubscriptionReceives>d__7.MoveNext() in C:\snip\Connection.cs:line 67
On the server, I get this at the completion queue next() call:
Exception thrown: read access violation.
core_cq_tag->**** was 0xDDDDDDDD.
The stack trace:
MyModule.exe!grpc_impl::CompletionQueue::AsyncNextInternal(void * * tag, bool * ok, gpr_timespec deadline) Line 59 C++
> MyModule.exe!grpc_impl::CompletionQueue::Next(void * * tag, bool * ok) Line 176 C++
...snip...
It appears something is being added to the queue after shutdown. The difficulty is I have little visibility into what is being added into the queue and in what order.
I'm trying to write a server-side interceptor to log all requests & responses, but there seems to be no documentation. So far, poking through the API hasn't gotten me very far. Is there any documentation available on wiring up an interceptor in C++? Or, are there other approaches for troubleshooting timing conflicts between services?
Windows 11, Grpc.Core 1.27
What I've tried:
I first played with the GRPC_TRACE & GRPC_VERBOSITY environment variables. I was able to get some unhelpful output from the client, but nothing from the server. Of course, there's been lots of debugging, stripping the client & server down to barebones, disabling keep alives, ensuring we aren't using deadlines, having the services share a cancellation token, etc.
Update: I have found that the crash only happens when the client is run from an NUnit test. In that environment, the completion queue is getting more hits on Next(), but I'm still trying to figure out where they are coming from.
Is 1.27 the version you are using? That seems pretty old.. There might have been fixes since then.
For using the C++ server interception API, I think you would find this very useful - https://github.com/grpc/grpc/blob/0f2a0f5fc9b9e9b9c98d227d16575d106f1e8d43/test/cpp/end2end/server_interceptors_end2end_test.cc#L48
One suggestion I have is to run the code another sanitizers https://github.com/google/sanitizers to make sure that we don't have a heap-use-after-free type bug.
I would also check for API misuse issues. (If you had posted the code, I could've given a look to see if anything seems weird..)
I want to use mbeans on startup of j2ee application to check if all the MDBs are running and jms specification has been activated.
Any pointers will be very helpful
The only way I know of to do this would be to use the ServerEndpointControl MBean. This is a Liberty specific MBean for controlling the input sources for work into the runtime. This can also be used to get status on http listeners.
The best place to find the Javadoc for the MBean is here. To find out if an MBean is running you call the isPaused method providing the MDB name which is defined as:
ApplicationName#ModuleName#BeanName
if the MDB is running it'll return false.
IBM WAS: 8.5.5 Version
On JSP pages have & tags, I receive below error
Error 500: java.lang.Exception: java.lang.VerifyError: JVMVRFY012
stack shape inconsistent; class=com/ibm/_jsp/_desktop,
method=_jspx_meth_c_set_0(Ljavax/servlet/jsp/PageContext;)Z, pc=73;
Type Mismatch, argument 1 in signature
org/apache/jasper/el/ELContextWrapper.:(Ljavax/el/ELContext;Ljavax/el/FunctionMapper;)V
does not match Exception Details:
Location:
com/ibm/_jsp/_desktop._jspx_meth_c_set_0(Ljavax/servlet/jsp/PageContext;)Z
#73: JBinvokespecial Reason: Type
'org/apache/jasper/runtime/ProtectedFunctionMapper' (current frame,
stack[8]) is not assignable to 'javax/el/FunctionMapper'
Current Frame: bci: #73 flags: { } locals: { 'com/ibm/_jsp/_desktop',
'javax/servlet/jsp/PageContext', 'javax/servlet/jsp/JspWriter',
'org/apache/taglibs/standard/tag/rt/core/SetTag' } stack: {
'org/apache/taglibs/standard/tag/rt/core/SetTag', 'uninitialized',
'uninitialized', 'java/lang/String', 'javax/el/ExpressionFactory',
'uninitialized', 'uninitialized', 'javax/el/ELContext',
'org/apache/jasper/runtime/ProtectedFunctionMapper' } Stackmap Table:
append_frame(#128,Object[#127],Object[#231],integer)
On reading https://www.ibm.com/support/pages/ibm-java-linux-howto-resolving-javalangverifyerror-jvmvrfy012-stack-shape-inconsistent, understand that the reason could be
code is compiled against a different library than the one being used at runtime
a class tries to extend a class declared as final
a method tries to override a super method that is declared as final
a wrong argument is passed to a method
It does look to be #4 - but the same code works in Tomcat and does not work in IBM WAS and am unsure why WAS is passing an incorrect argument. Any suggestions on how we can resolve this issue?
You may want to explore Servlet/JSP version compatibility.
WAS: 8.5.5 reference
Servlet 3.0
JSP 2.2
If you happen to be using Spring Boot:
2.2.x and 2.1.x require Servlet 3.1+
2.0.x supports Servlet 3.0
This looks like a cross-linkage between the javax.el library in your application and the version packaged in the server. When using PARENT_LAST, any Java EE APIs you include in the application are loaded twice, once from the server and once from the application (because the application loader doesn't delegate that load to its parents). Depending on the other classes/packages in play, you can have an instance in which a class ends up directly referencing one instance of the class and indirectly (through some other reference) referencing the other instance, and the JVM will throw a VerifyError in that scenario.
The easiest answer: If you are not 200% sure you NEED the version of the javax.el classes in the app, remove them, and this specific error should be impossible. If you are definitely dependent on that version, then it becomes trickier, as it might require adding additional stuff to the application (to avoid picking stuff up from the server), or it may be that this specific library simply can't be safely overridden with PARENT_LAST loading. That analysis would require a deeper look at the error stack and possibly a dive into detail trace of the class loading.
I don't have any errors with my smart target application, but I do see in the event log, the following error messages:
ERROR 2012-09-19 14:30:09
com.tridion.smarttarget.utils.AmbientDataHelper - can't find defined
trigger-types in claim store (check if your smarttarget cartridge is
up and running)
and:
ERROR 2012-09-19 14:30:11
com.tridion.smarttarget.tags.TimeoutQueryRunner - The fredhopper query
timed out java.util.concurrent.TimeoutException at
java.util.concurrent.FutureTask$Sync.innerGet(Unknown Source) at
java.util.concurrent.FutureTask.get(Unknown Source) at
com.tridion.smarttarget.tags.TimeoutQueryRunner.executeQuery(TimeoutQueryRunner.java:64)
ERROR 2012-09-19 14:30:11
com.tridion.smarttarget.tags.TimeoutQueryRunner - The fredhopper query
timed out
I would really like to understand what is causing these and how I can remove them. Or some suggested steps to help me debug this would be great :)
As I say, everything is working perfectly, later on in the logs I see the query to ST is correct and the results being generated.
In the event that is helps, I'm running on a 2009 implementation with Smart Target 2010, java 1.5.
thanks
John
Sounds like you might have a trigger configured in ST that does not actually exist in the ADF (or is mismatched). Have you looked through your trigger-types.xml file for anything obvious? Have you disabled an ADF cartridge but not removed the corresponding trigger in the XML perhaps? See the documentation for Defining trigger types.
I think your timeout is coming from the SmartTarget region rather than FredHopper. Sometimes a query that isn't already cached in FredHopper can take a while to return, even though it's ultimately successful. The ST query tag has a timeout (defined in the smarttarget_conf.xml file, or over-ridden with a tag attribute) that it will wait for a response from Fredhopper for before resorting to using the fallback content. This might explain why you see later in the logs that the query is correct and that results are returned. See the documentation for <tcdl:query>.
No conclusive answer for you I'm afraid, but I hope that helps.
The first error is logged if your SmartTarget cartridge is not running -- or if the data that it puts into ADF is lost somehow (e.g. you have disabled sessions in your web server).
In that case, SmartTarget will still do a query but it won't include anything from the Ambient Data Framework in it. If you don't have any triggers based on ambient data, the end result is the same for you.
To get rid of the error, make sure that smarttarget_cartridge is configured correctly.
As for the timeout error, it simply means that the query sent to Fredhopper took longer than the configured time. In that case it will show the fallback content instead. If this is happening a lot, you might want to increase the timeout within smarttarget_conf.xml.
I hope you found the issue, but for future reference, the first error message is raised when the claim "taf:claim:ambientdata:definedtriggertypes" is not set by the SmartTarget cartridge. This can be caused by:
SmartTarget cartridge could not load the the trigger types from the SmartTarget server. The log will show an error "can't retrieve list of defined trigger types from FH".
The HTTP session on your web server is expired during an active visit (the HTTP session expired but the browser is still open) and the claim is "lost".
The server does not support sessions like Peter mentioned.
I converted a standalone Flex app into a module. Now that it's a module, when I login (and call the backend services), I'm getting a security sandbox violation.
The login handler throws this fault String: 'Send Failed', with a more descriptive: 'Channel.Connect.Failed error NetConnection.Call.Failed: HTTP: Failed:url: 'http://myUrl:8080/AppManager/messagebroker/amf'.
Then the FB console throws an 'unhandled security sandbox violation error'.
Can converting an app into a module cause a sandbox violation?
Thanks for any helpful tips.
I'm making extensive use of modules and haven't run into this. There are memory issues I ran into that I had to fix by actually declaring an instance of the modules in the main modules...I didn't have to create an instance, just declare a variable to get the linkage right, then have all the other modules compile against that main module. Memory errors went away, and all the other modules were much smaller too.