QuotaExceededException as a DoNotRetryIOException?

[Huaxiang Sun]

Hi HBase devs,

    I found that QuotaExceededException  is a DoNotRetryIOException, which is a 
bit strange from user’s point of view.
    For rpc throttling, the exception is retryable and it tells app to slow 
down and retry later.

    Any thoughts?

    Thanks,
    Huaxiang