ZK 3.8.4 uses the LogBack feature for logging, which uses 2 libraries  logback-core-1.2.13.jar logback-classic-1.2.13.jar ( Missing Jar ) one of them was missing from my bundle. I downloaded and copied the jar in zookeeper/lib/ dir and restarted the service. This worked for me. Steps - Locate the logback jar, download the other missing jar, and paste in that dir. cd /opt/ wget https://repo1.maven.org/maven2/ch/qos/logback/logback-classic/1.2.13/logback-classic-1.2.13.jar cksum logback-classic-1.2.13.jar | grep -i "103870831 232073" chown root:root logback-classic-1.2.13.jar cp logback-classic-1.2.13.jar /usr/odp/3.3.6.0-1/zookeeper/lib/ cp logback-classic-1.2.13.jar /usr/odp/3.3.6.0-1/cruise-control3/dependant-libs/ ... View more

The problem seemed to be caused by wrong access policies on PG under the root. With the wrong credentials the name attribute of certain PG was not returned in the response which caused pg-list to fail. Adding read policy for the credentials on the PGs solved the case. ?! Regards ... View more