TaskTracker not starting -CDH5.8.1

[#1]

Dear Team,

Task tracker is not starting on one of the datanode. It showing "error found before invoking supervisord: dictionary update sequence element #84 has legth 1;2 is required” in CDH5.8.1 cluster. Attached is the screenshot of an error.

[#2 · Accepted solution]

Try stopping all roles and restarting your CM agent on just this host and ensure you do not use the init.d script directly, and that instead you use the recommended service command approach:

~> service cloudera-scm-agent restart

(i.e., never do this: "~> /etc/init.d/cloudera-scm-agent restart")