/kind bug

What steps did you take and what happened:

I use tfjob as trial's job, my tfjob has one ps, one chief, one worker, and the metric collector is stdout, but I find that the metrics-logger-and-collector container sometimes will become error, and the print like above, this isn't must present.
But this will cause that the worker‘s metric can't be collected.

this error message in code like this:

can you give me some advice to aviod this problem?

What did you expect to happen:
don't appear this error

Environment:

• katib version (kfctl version): v0.10.1
• Kubernetes version: (use kubectl version): 1.13