tree 95cb8da0bb339ea6413fd33b86640e7ad0b94ac4
parent 6f1756cffbde5c58075dc2d2dc8a7a8ea51516fe
author jerryshao <sshao@hortonworks.com> 1527212163 +0800
committer jerryshao <sshao@hortonworks.com> 1527212163 +0800

[LIVY-472][SERVER] Improve the logs for fail-to-create session

## What changes were proposed in this pull request?

Livy currently doesn't give a very clear log about the fail-to-create session, it only says that session related app tag cannot be found in RM, but doesn't tell user how to search and get the true root cause. So here change the logs to make it more clear.

## How was this patch tested?

Local verification.

Author: jerryshao <sshao@hortonworks.com>

Closes #96 from jerryshao/LIVY-472.