Webconsole MemoryUsage stacktrace after Karaf 4.4.11 upgrade

[ponziani]

After upgrading to Karaf 4.4.11, I’m seeing the stacktrace below in the logs.

Additionally, I noticed that the bundle org.apache.felix.webconsole.plugins.memoryusage-1.1.0 now imports the package org.apache.felix.webconsole.servlet, but this package does not appear to be exported by org.apache.karaf.webconsole.console-4.4.11.

This seems to leave the import unresolved after the upgrade.

Could you confirm whether this is an expected change in 4.4.11, or if an export is missing from the Karaf webconsole console bundle?

Kind regards,
Steven

2026-05-05 10:31:54,303 - [E.Framework         ][FelixDispatchQueue] ERROR - FrameworkEvent ERROR
 org.osgi.framework.ServiceException: Service factory exception: org/apache/felix/webconsole/servlet/AbstractServlet
at org.apache.felix.framework.ServiceRegistrationImpl.getFactoryUnchecked(ServiceRegistrationImpl.java:354)
at org.apache.felix.framework.ServiceRegistrationImpl.getService(ServiceRegistrationImpl.java:249)
at org.apache.felix.framework.ServiceRegistry.getService(ServiceRegistry.java:362)
at org.apache.felix.framework.Felix.getService(Felix.java:3984)
at org.apache.felix.framework.BundleContextImpl.getService(BundleContextImpl.java:450)
at org.apache.felix.inventory.impl.InventoryPrinterManagerImpl.addingService(InventoryPrinterManagerImpl.java:127)
at org.apache.felix.inventory.impl.InventoryPrinterManagerImpl.addingService(InventoryPrinterManagerImpl.java:48)
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerAdding(ServiceTracker.java:943)
at org.osgi.util.tracker.ServiceTracker$Tracked.customizerAdding(ServiceTracker.java:871)
at org.osgi.util.tracker.AbstractTracked.trackAdding(AbstractTracked.java:256)
at org.osgi.util.tracker.AbstractTracked.track(AbstractTracked.java:229)
at org.osgi.util.tracker.ServiceTracker$Tracked.serviceChanged(ServiceTracker.java:903)
at org.apache.felix.framework.EventDispatcher.invokeServiceListenerCallback(EventDispatcher.java:990)
at org.apache.felix.framework.EventDispatcher.fireEventImmediately(EventDispatcher.java:838)
at org.apache.felix.framework.EventDispatcher.fireServiceEvent(EventDispatcher.java:545)
at org.apache.felix.framework.Felix.fireServiceEvent(Felix.java:4863)
at org.apache.felix.framework.Felix.registerService(Felix.java:3834)
at org.apache.felix.framework.BundleContextImpl.registerService(BundleContextImpl.java:328)
at org.apache.felix.webconsole.plugins.memoryusage.internal.Activator$AbstractServiceFactory.<init>(Activator.java:109)
at org.apache.felix.webconsole.plugins.memoryusage.internal.Activator$2.<init>(Activator.java:61)
at org.apache.felix.webconsole.plugins.memoryusage.internal.Activator.start(Activator.java:59)
at org.apache.felix.framework.util.SecureAction.startActivator(SecureAction.java:849)
at org.apache.felix.framework.Felix.activateBundle(Felix.java:2429)
at org.apache.felix.framework.Felix.startBundle(Felix.java:2335)
at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:1006)
at org.apache.felix.framework.BundleImpl.start(BundleImpl.java:992)
at org.apache.karaf.features.internal.service.BundleInstallSupportImpl.startBundle(BundleInstallSupportImpl.java:165)
at org.apache.karaf.features.internal.service.FeaturesServiceImpl.startBundle(FeaturesServiceImpl.java:1160)
at org.apache.karaf.features.internal.service.Deployer.deploy(Deployer.java:1041)
at org.apache.karaf.features.internal.service.FeaturesServiceImpl.doProvision(FeaturesServiceImpl.java:1069)
at org.apache.karaf.features.internal.service.FeaturesServiceImpl.lambda$doProvisionInThread$13(FeaturesServiceImpl.java:1004)
at java.base/java.util.concurrent.FutureTask.run(FutureTask.java:264)
at java.base/java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1136)
at java.base/java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:635)
at java.base/java.lang.Thread.run(Thread.java:840)
Caused by: java.lang.NoClassDefFoundError: org/apache/felix/webconsole/servlet/AbstractServlet
at java.base/java.lang.ClassLoader.defineClass1(Native Method)
at java.base/java.lang.ClassLoader.defineClass(ClassLoader.java:1017)
at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.defineClass(BundleWiringImpl.java:2338)
at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.defineClassParallel(BundleWiringImpl.java:2156)
at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.findClass(BundleWiringImpl.java:2090)
at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1556)
at org.apache.felix.framework.BundleWiringImpl.access$300(BundleWiringImpl.java:79)
at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1976)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
at org.apache.felix.webconsole.plugins.memoryusage.internal.Activator$2.createObject(Activator.java:65)
at org.apache.felix.webconsole.plugins.memoryusage.internal.Activator$AbstractServiceFactory.getService(Activator.java:126)
at org.apache.felix.framework.ServiceRegistrationImpl.getFactoryUnchecked(ServiceRegistrationImpl.java:349)
... 34 more
Caused by: java.lang.ClassNotFoundException: org.apache.felix.webconsole.servlet.AbstractServlet not found by org.apache.felix.webconsole.plugins.memoryusage [316]
at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1591)
at org.apache.felix.framework.BundleWiringImpl.access$300(BundleWiringImpl.java:79)
at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:1976)
at java.base/java.lang.ClassLoader.loadClass(ClassLoader.java:525)
... 46 more

[jbonofre]

Thanks for the issue. Let me investigate.

[jbonofre]

OK, that's a version mismatch between the webconsole and the plugin. The plugin expects a new WebConsole version that introduced the AbtractServlet.
I will downgrade the plugin on the karaf-4.4.x branch, to be included in the 4.4.12 release.