Develop Reference

Connect Java Mission Control to Wildfly 16

I try to connect Java Mission Control (JMC) with Wildfly 16. Application server lays on Docker.
I successfully connected to wildfly via jconsole, to manage it I followed steps described here.
Unfortunately, I have no luck to connect via JMC. The URL which I use looks like this:
service:jmx:remoting-jmx://192.168.99.100:9990
I tried to set Xbootclasspath to jboss-cli-client.jar as it was described here, but I just get Unable to connect error.
I set the same jars, which are used for jconsole, but still I got Unable to connect.
I gave a try to adding flags on container site, as it was shown here, but with these flags, even wildfly haven't started.
Then, I found here the idea to hardcode some jboss classes to enable connection via remoting-jmx. I changed version of jars, according to these provided by wildfly16 and put it to jmc.ini like this.
-Xbootclasspath/a:"C:/Program Files/Java/jdk-10.0.2/lib/missioncontrol/dropins/jboss-cli-client.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/remoting-jmx/main/remoting-jmx-3.0.1.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/remoting/main/jboss-remoting-5.0.8.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/logging/main/jboss-logging-3.3.2.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/xnio/main/xnio-api-3.6.5.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/xnio/nio/main/xnio-nio-3.6.5.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/marshalling/main/jboss-marshalling-2.0.6.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/marshalling/river/main/jboss-marshalling-river-2.0.6.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/as/cli/main/wildfly-cli-8.0.0.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/staxmapper/main/staxmapper-1.3.0.Final;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/as/protocol/main/wildfly-protocol-8.0.0.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/dmr/main/jboss-dmr-1.5.0.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/as/controller-client/main/wildfly-controller-client-8.0.0.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/threads/main/jboss-threads-2.3.3.Final.jar;C:/wildfly-16.0.0.Final/modules/system/layers/base/org/jboss/logmanager/main/jboss-logmanager-2.1.7.Final.jar"
After that, finally, I have another error, which is
Could not initialize class org.jboss.remotingjmx.RemotingConnector
I added dependencies of remoting-jmx-3.0.1.Final to Xbootclasspath, but I got still the same error.
My question is, have you got any idea, how to make this connection works ? Maybe someone have done it in different way ?
Any advices how can i debug this problem, will be priceless? Because I'm lack of ideas how to solve it.

In %WILDFLY_HOME%\bin\standalone.conf.bat
put:
set "JAVA_OPTS=%JAVA_OPTS% -XX:+FlightRecorder"
In jmc.ini below -vmargs put
-Xbootclasspath/a:C:\%wildfly_home%\bin\client\jboss-cli-client.jar
(%wildfly_home% is different of course, or just copy jboss-cli-client.jar to another directory and correct the path)
3. Run JMC, then Create New Connection - in Connection Properties pane push the button "Custom JMX service URL", put:
service:jmx:http-remoting-jmx://localhost:9990
In the credentials fields just put user and password, they should be created for Realm Management (e.g. using %wildfly_home%\bin\add-user.bat)
Hope this helps someone.

Solution doesn't work on java 11 for me. Mission control fails on connect to wildfly with error:
Caused by: java.lang.NoClassDefFoundError: org/ietf/jgss/GSSManager
at java.base/java.lang.Class.getDeclaredConstructors0(Native Method)
at java.base/java.lang.Class.privateGetDeclaredConstructors(Class.java:3137)
at java.base/java.lang.Class.getConstructor0(Class.java:3342)
at java.base/java.lang.Class.getConstructor(Class.java:2151)
at java.base/java.security.Provider.newInstanceUtil(Provider.java:152)
at java.base/java.security.Provider$Service.newInstance(Provider.java:1824)
at org.wildfly.security.WildFlyElytronBaseProvider$ProviderService.newInstance(WildFlyElytronBaseProvider.java:218)
at org.wildfly.security.sasl.util.SecurityProviderSaslClientFactory.createSaslClient(SecurityProviderSaslClientFactory.java:94)
at org.wildfly.security.sasl.util.AbstractDelegatingSaslClientFactory.createSaslClient(AbstractDelegatingSaslClientFactory.java:66)
at org.wildfly.security.sasl.util.ProtocolSaslClientFactory.createSaslClient(ProtocolSaslClientFactory.java:50)
at org.wildfly.security.sasl.util.AbstractDelegatingSaslClientFactory.createSaslClient(AbstractDelegatingSaslClientFactory.java:66)
at org.wildfly.security.sasl.util.ServerNameSaslClientFactory.createSaslClient(ServerNameSaslClientFactory.java:50)
at org.wildfly.security.sasl.util.AbstractDelegatingSaslClientFactory.createSaslClient(AbstractDelegatingSaslClientFactory.java:66)
at org.wildfly.security.sasl.util.ServerNameSaslClientFactory.createSaslClient(ServerNameSaslClientFactory.java:50)
at org.wildfly.security.sasl.util.FilterMechanismSaslClientFactory.createSaslClient(FilterMechanismSaslClientFactory.java:102)
at org.wildfly.security.sasl.util.AbstractDelegatingSaslClientFactory.createSaslClient(AbstractDelegatingSaslClientFactory.java:66)
at org.wildfly.security.sasl.util.LocalPrincipalSaslClientFactory.createSaslClient(LocalPrincipalSaslClientFactory.java:76)
at org.wildfly.security.sasl.util.PrivilegedSaslClientFactory.lambda$createSaslClient$0(PrivilegedSaslClientFactory.java:64)
at java.base/java.security.AccessController.doPrivileged(Native Method)
at org.wildfly.security.sasl.util.PrivilegedSaslClientFactory.createSaslClient(PrivilegedSaslClientFactory.java:64)
at org.wildfly.security.auth.client.AuthenticationConfiguration.createSaslClient(AuthenticationConfiguration.java:1545)
at org.wildfly.security.auth.client.AuthenticationContextConfigurationClient.createSaslClient(AuthenticationContextConfigurationClient.java:430)
at org.jboss.remoting3.remote.ClientConnectionOpenListener$Capabilities.handleEvent(ClientConnectionOpenListener.java:419)
at org.jboss.remoting3.remote.ClientConnectionOpenListener$Capabilities.handleEvent(ClientConnectionOpenListener.java:244)
at org.xnio.ChannelListeners.invokeChannelListener(ChannelListeners.java:92)
at org.xnio.conduits.ReadReadyHandler$ChannelListenerHandler.readReady(ReadReadyHandler.java:66)
at org.xnio.nio.NioSocketConduit.handleReady(NioSocketConduit.java:89)
at org.xnio.nio.WorkerThread.run(WorkerThread.java:591)
Besides, jmc that was embedded to jdk 8 isn't able to start flight recording for java 11 process.
So after investigation i found out that this class is loaded with bootstrap classloader. According to https://openjdk.java.net/jeps/261
jdk.security.jgss module isn't defined to bootstrap classloader. But classes in jboss-cli-client.jar(it originates from wildfly-elytron project) need jgss classes in runtime.
So i found out dirty workaround for this problem: bootstrap needed classes from jre 8 in jmc.ini. Full option for linux is:
-vmargs -Xbootclasspath/a:<path_to_wildfly>/jboss-cli-client.jar:<path_to_jdk8>/jre/lib/rt.jar
And for windows:
-vmargs -Xbootclasspath/a:<path_to_wildfly>\jboss-cli-client.jar;<path_to_jdk8>\jre\lib\rt.jar
after this jmc(run on 11 jdk) succesfully connects to wildfly(run on 11 jdk) and can start and analyze flight recordings.

Jenkins fails to start up and empty plugins directory

I am new to jenkins, I upgraded a couple of plugins(don't remember which), after that I when I try java -jar jenkins.war I end up getting the following error.
jenkins.InitReactorRunner$1 onTaskFailed
SEVERE: Failed Loading global config
java.io.IOException: Unable to read /home/.jenkins/config.xml
I went through several links which address this issue, but no luck yet. In this link which I found https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=764711 it says some plugins are missing, and surprisingly, my /home/.jenkins/plugins/ is empty!!!
How do I restore the necessary plugins from my command line?
I am using CentOS release 6.8 (Final)
Thank you :)

I had encountered this issue somedays back,however after restarting jenkins service solved the issue.
The best you can do now is rename your config file. This way jenkins will load with the default startup.

Activiti Explorer - Request resource is not available

I have big problem to run activiti-explorer when i try access: http://localhost:8080/activiti-explorer/ tomcat shows me HTTP Status 404 - The requested resource is not available. I'm really don't have any idea why that dosen't work. Can you help me?
This what have I done on my PC:
I'm using 5.19.0 version of activiti-explorer
7.0.63 tomcat
JDK 1.8.0.77 (i think there is no point to downgrade java to previous versions (<=1.7) becouse my main application using this version)
I'm sure I have correctly configured environment variables (JAVA_HOME,JRE_HOME,PATH,CATALINA_HOME)
I configured data base connection (db.properties, context.xml) in activiti-explorer.war and i moved this file to tomcat/webapps
I don't have any errors about activiti during tomcat start

Check if activiti explorer is deployed to tomcat in manager.
http://{host}:{port}/manager/html
More info in https://tomcat.apache.org/tomcat-7.0-doc/manager-howto.html

Check the catalina.out log. There will be something in there that leads you to the solution.

Check Admin Console (cmd that runs behind) after hitting the link. most recent exception occurred will be displayed there.

STS 3.6 RELEASE error running server

When I run my project, I don't have errors.
But After login, when I try to enter in a form page the application give me the follow error:
GRAVE: Servlet.service() for servlet jsp threw exception
java.util.NoSuchElementException
at java.util.ArrayList$Itr.next(Unknown Source)
at org.apache.jasper.compiler.Validator$ValidateVisitor.getJspAttribute(Validator.java:1381)
at org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:772)
at org.apache.jasper.compiler.Node$UninterpretedTag.accept(Node.java:1251)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2375)
at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2427)
at org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:779)
at org.apache.jasper.compiler.Node$UninterpretedTag.accept(Node.java:1251)
at org.apache.jasper.compiler.Node$Nodes.visit(Node.java:2375)
at org.apache.jasper.compiler.Node$Visitor.visitBody(Node.java:2427)
at org.apache.jasper.compiler.Validator$ValidateVisitor.visit(Validator.java:895)
...
I think the problem is in the configuration of tomcat but I don't understand where.
I have tomcat7.0.52, use java version 1.7.0_60, idem for jdk.
At my colleague work all without problems, we have the same tomcat version, the only difference is that I have STS 3.6 RELEASE, and He have the 3.5.
EDIT:
I try to delete server, and recreate it, but the problem don't change.
I think that the problem is on wrong configuration server because any project I run give me the same error.
This is my catalina arguments:
-Dcatalina.base="/home/paola/Documenti/sts-bundle/vfabric-tc-server-developer-2.9.6.RELEASE/base-instance"
-Dcatalina.home="/home/paola/Documenti/sts-bundle/vfabric-tc-server-developer-2.9.6.RELEASE/tomcat-7.0.53.B.RELEASE"
-Dwtp.deploy="/home/paola/Documenti/sts-bundle/vfabric-tc-server-developer-2.9.6.RELEASE/base-instance/wtpwebapps"
-Djava.endorsed.dirs="/home/paola/Documenti/sts-bundle/vfabric-tc-server-developer-2.9.6.RELEASE/tomcat-7.0.53.B.RELEASE/endorsed" -Xmx768m -Xss256k -XX:MaxPermSize=256m
-Dinsight.enabled=false -Dspring.profiles.active=dev
Any ideas?
Thank

It looks like the problem is with the version of Tomcat that tcServer is derived from.
This bug which is fixed in Tomcat 7.0.55 is looks like the cause.
I've done some testing and found that the bug is not present in Tomcat 7.0.50, which is used by tcServer Dev Edition 2.9.5.SR1.
So it's either 7.0.51 or 7.0.52 (as you discovered) which introduced the bug.

Unable to start server in Eclipse Gallileo IDE with WAS7

Server not starting in Eclipse Gallileo IDE with WAS7.
I run the server from outside of Eclipse but I want to start it from within the eclipse
Below are the details of my Workspace configurations :
Eclipse Java EE IDE for Web Developers.
WAS 7.0
An alert is coming saying "Cannot connect to VM socket closed".
I got the following exception in console :
JVMSHRC154E Escape character g not valid for cache name
<JIT: FullSpeedDebug: ignoring countString>
<JIT: FullSpeedDebug: ignoring countString>
JVMJ9VM015W Initialization error for library j9shr24(13): JVMJ9VM009E J9VMDllMain failed

Per the JVMSHRC154E, it appears that somehow -Xshareclasses:name=...%g... is being added to your server JVM command line. I do not know why there would be a difference between Eclipse and the command-line (perhaps a product issue that should be reported to IBM), but you could try working around the issue by adding -Xshareclasses:nonfatal to your server's generic JVM arguments.

IBM has released development tools for WebSphere Application Server (WAS).
You can download it from eclipse market place.
There are tools for the WAS7 and up. (IBM Information page)
You probably need WAS 7 Tools - marketplace page.
The short instruction is:
In the eclipse click Help->Eclipse Market Place->Search WebSphere Application Server Tools.

Inside eclipse installation folder go to \plugins.....\cdcla\eclipse\launch\simple.
Open the file websphere70.properties.
You will see the following content and remove the
"_%g"
part and save it
shareclasses=webspherev70_%g,groupAccess,nonfatal