Can't start the tasktracker

[#1]

I can't start the tasktracker with the cloudera manager. 

It show the error message:“error found before invoking supervisord: dictionary update sequence element #84 has legth 1;2 is required”.

The cluster  doesn't  create the log file. 

[#2 · Accepted solution]

I know the reason now.

Anybody who meets the same problem can refer to  this answer.

http://community.cloudera.com/t5/Cloudera-Manager-Installation/cloudera-manager-agent-bug-report-can...