ehcache bundle requires dynamic-import to avoid ClassNotFoundException when persistence cache is initialized.

Attached is the reproducer, unzip it and build it using command 'mvn clean install'. Deploy it in Red Hat Fuse 7.x with command feature:install camel-ehcache osgi:install -s mvn:com.mycompany/cache-test/1.0.0 Application starts well. Now restart Red Hat Fuse. In star up logs we will identify following exception Caused by: java.lang.IllegalStateException: Persisted value type class not found at org.ehcache.impl.internal.store.disk.OffHeapDiskStore.recoverBackingMap(OffHeapDiskStore.java:195) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore.getBackingMap(OffHeapDiskStore.java:159) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore.access$600(OffHeapDiskStore.java:93) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore$Provider.init(OffHeapDiskStore.java:446) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore$Provider.initStore(OffHeapDiskStore.java:442) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore$Provider.initAuthoritativeTier(OffHeapDiskStore.java:494) ~[?:?] at org.ehcache.impl.internal.store.tiering.TieredStore$Provider.initStore(TieredStore.java:445) ~[?:?] at org.ehcache.core.EhcacheManager$8.init(EhcacheManager.java:511) ~[?:?] at org.ehcache.core.StatusTransitioner.runInitHooks(StatusTransitioner.java:135) ~[?:?] at org.ehcache.core.StatusTransitioner.access$000(StatusTransitioner.java:33) ~[?:?] at org.ehcache.core.StatusTransitioner$Transition.succeeded(StatusTransitioner.java:194) ~[?:?] at org.ehcache.core.EhcacheBase.init(EhcacheBase.java:572) ~[?:?] at org.ehcache.core.EhcacheManager.createCache(EhcacheManager.java:266) ~[?:?] at org.ehcache.core.EhcacheManager.createCache(EhcacheManager.java:243) ~[?:?] at com.mycompany.ehcache.MySimpleCacheManager.createCache(MySimpleCacheManager.java:101) ~[?:?] ---- --- ... 28 more Caused by: java.lang.ClassNotFoundException: com.mycompany.ehcache.domain.User not found by org.ehcache.ehcache [228] at org.apache.felix.framework.BundleWiringImpl.findClassOrResourceByDelegation(BundleWiringImpl.java:1639) ~[?:?] at org.apache.felix.framework.BundleWiringImpl.access$200(BundleWiringImpl.java:80) ~[?:?] at org.apache.felix.framework.BundleWiringImpl$BundleClassLoader.loadClass(BundleWiringImpl.java:2053) ~[?:?] at java.lang. ClassLoader .loadClass( ClassLoader .java:357) ~[?:?] at org.ehcache.core.internal.util.ClassLoading$DefaultClassLoader.loadClass(ClassLoading.java:57) ~[?:?] at java.lang. Class .forName0(Native Method) ~[?:?] at java.lang. Class .forName( Class .java:348) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore.recoverBackingMap(OffHeapDiskStore.java:190) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore.getBackingMap(OffHeapDiskStore.java:159) ~[?:?] at org.ehcache.impl.internal.store.disk.OffHeapDiskStore.access$600(OffHeapDiskStore.java:93) ~[?:?] Now if stop fuse and we delete the folder/files created at permanent CACHE_PATH configured at class MySimpleCacheManager. [cpandey@cpandey esb-cache]$ pwd /tmp/esb-cache [cpandey@cpandey esb-cache]$ tree . └── mySimpleCache └── file └── USER_CACHE_1271916c53257f36f0a0b7d732ce5f3c68871d28 ├── offheap-disk-store │   ├── ehcache-disk-store.data │   ├── ehcache-disk-store.index │   └── ehcache-disk-store.meta └── value-serializer └── holder-0-CompactJavaSerializer-ObjectStreamClassIndex.bin 5 directories, 4 files [cpandey@cpandey esb-cache]$ rm -rf * After deleting cache and than restarting Red Hat Fuse, we don't observe this issue again. Nice workaround to this problem is that enable dynamic-import on ehcache bundle. karaf@root()> list|grep ehcache 227 │ Active │ 50 │ 2.21.0.fuse-731003-redhat-00003 │ camel-ehcache 228 │ Active │ 50 │ 3.5.0 │ ehcache 3 karaf@root()> dynamic- import 228 Enabling dynamic imports on bundle org.ehcache.ehcache [228] karaf@root()> Dynamic Import is helpful but enabling dynamic-import is considered to be an anti-pattern. We should have dependencies resolved with Import-Package Manifest header. Problem is this ehcache bundle is not a custom bundle it is being shipped with Red Hat Fuse. Also why this ehcache bundle is failing with classnotfound exception for custom/user-defined class ? With fix https://issues.apache.org/jira/browse/SMX4-1303 (ancient fix) it appears that dynamic-import should have been a part of ehcache manifest file.