question Re: zkFC Initialization: Could not instantiate appender named "EventCatcher". in Support Questions

zkFC Initialization: Could not instantiate appender named "EventCatcher".

Yasine — Fri, 18 Aug 2023 13:48:25 GMT

Hi,

We are getting an error when initializing the zk Failover Controller here the error below:

WARNING: HADOOP_ZKFC_OPTS has been replaced by HDFS_ZKFC_OPTS. Using value of HADOOP_ZKFC_OPTS.
log4j:ERROR Could not instantiate class [com.cloudera.cmf.eventcatcher.client.logs.ExceptionForwarderAppender].
java.lang.ClassNotFoundException: com.cloudera.cmf.eventcatcher.client.logs.ExceptionForwarderAppender
at java.net.URLClassLoader.findClass(URLClassLoader.java:387)
at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
at java.lang.Class.forName0(Native Method)
at java.lang.Class.forName(Class.java:264)
at org.apache.log4j.helpers.Loader.loadClass(Loader.java:198)
at org.apache.log4j.helpers.OptionConverter.instantiateByClassName(OptionConverter.java:327)
at org.apache.log4j.helpers.OptionConverter.instantiateByKey(OptionConverter.java:124)
at org.apache.log4j.PropertyConfigurator.parseAppender(PropertyConfigurator.java:785)
at org.apache.log4j.PropertyConfigurator.parseCategory(PropertyConfigurator.java:768)
at org.apache.log4j.PropertyConfigurator.configureRootCategory(PropertyConfigurator.java:648)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:514)
at org.apache.log4j.PropertyConfigurator.doConfigure(PropertyConfigurator.java:580)
at org.apache.log4j.helpers.OptionConverter.selectAndConfigure(OptionConverter.java:526)
at org.apache.log4j.LogManager.<clinit>(LogManager.java:127)
at org.slf4j.impl.Log4jLoggerFactory.<init>(Log4jLoggerFactory.java:66)
at org.slf4j.impl.StaticLoggerBinder.<init>(StaticLoggerBinder.java:72)
at org.slf4j.impl.StaticLoggerBinder.<clinit>(StaticLoggerBinder.java:45)
at org.slf4j.LoggerFactory.bind(LoggerFactory.java:150)
at org.slf4j.LoggerFactory.performInitialization(LoggerFactory.java:124)
at org.slf4j.LoggerFactory.getILoggerFactory(LoggerFactory.java:417)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:362)
at org.slf4j.LoggerFactory.getLogger(LoggerFactory.java:388)
at org.apache.hadoop.ha.ZKFailoverController.<clinit>(ZKFailoverController.java:65)
log4j:ERROR Could not instantiate appender named "EventCatcher".

Any idea ?

Regards

Re: zkFC Initialization: Could not instantiate appender named "EventCatcher".

venkatsambath — Fri, 18 Aug 2023 16:18:23 GMT

The ERROR message indicates a particular logger class is not available. Usually logger errors wouldn't fail the actual action. Can you clarify what command/action you triggered from CM Role action and in CM whether the command is reported as successful or failed?

A screenshot of the actual failure could be helpful to understand this better.

Re: zkFC Initialization: Could not instantiate appender named "EventCatcher".

DianaTorres — Mon, 21 Aug 2023 17:10:47 GMT

@Yasine Has the reply helped resolve your issue? If so, please mark the appropriate reply as the solution, as it will make it easier for others to find the answer in the future. If you are still experiencing the issue, can you provide the information @venkatsambath has requested? Thanks.

Re: zkFC Initialization: Could not instantiate appender named "EventCatcher".

Yasine — Tue, 22 Aug 2023 09:28:35 GMT

Unfortunetly this error message was blocking the ZK Failover Controller, so I solved this issue by deleting all Zookeeper data and disabled Kerberos authentifcation and then I started zkFailover controller and I re enabled the Kerberos authentication on Zookeeper.