Github user paul-rogers commented on the issue:
https://github.com/apache/drill/pull/1011
@kr-arjun, thanks for your note on error handling. Where you using the
`start` command? There is exactly one place where the error "Failed to start
Drill application master" is thrown: it is when Drill-on-YARN fails to start
the application master. There are lots of other messages for other issues such
as "Error: AM already running as Application ID: 1234" or "Failed to allocate
Drill application master."
When writing the client, I made an explicit decision not to create a log
file to avoid cluttering up things. There is no good place to put a client log
since Drill does not actually run on the client machine. We could add a log,
but it would be messy.
What we can do, however, is include the text of the message we got from
YARN when we tried to start the AM process. When an error occurs, the client
will now print something line the following:
```
Failed to start Drill application master.
Caused by: Some YARN error
```
The other thing we can add is a full stack dump, but only when requested
with the `-v` (verbose) option:
```
> drill-on-yarn.sh -v start
Failed to start Drill application master.
Caused by: Some YARN error
Full stack trace:
(stack trace here)
```
I can't easily test this code. Please grab the latest sources and rerun
your test case to ensure that it now prints out more information: whatever YARN
tells us about why it would not start the AM.
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