Forcing Legacy LB results in class not found exception error linked to zookeeper

[francescotimperioss]

I tried to force the Legacy LB using current Openwhisk 2 codebase, getting this Exception

[2025-12-13T20:01:13.783Z] [INFO] [#tid_sid_unknown] [InstanceIdAssigner] invokerReg: creating zkClient to zookeeper-0.zookeeper:2181 Exception in thread "main" java.lang.NoClassDefFoundError: org/apache/zookeeper/admin/ZooKeeperAdmin at org.apache.curator.framework.CuratorFrameworkFactory.<clinit>(CuratorFrameworkFactory.java:68) at org.apache.openwhisk.core.invoker.InstanceIdAssigner.setAndGetId(InstanceIdAssigner.scala:37) at org.apache.openwhisk.core.invoker.Invoker$.main(Invoker.scala:195) at org.apache.openwhisk.core.invoker.Invoker.main(Invoker.scala) Caused by: java.lang.ClassNotFoundException: org.apache.zookeeper.admin.ZooKeeperAdmin at java.base/jdk.internal.loader.BuiltinClassLoader.loadClass(Unknown Source) at java.base/jdk.internal.loader.ClassLoaders$AppClassLoader.loadClass(Unknown Source) at java.base/java.lang.ClassLoader.loadClass(Unknown Source) ... 4 more

I agree that nowadays this is not anymore the recommended setup, but on paper it is still supported so a gave a try to this type of setup getting the above error.

The invoker includes zookeeper 3.4.14, whilst the ZookeeperAdmin required by the curator framework has been introduced by version 3.5.X.