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From Paul Rogers <prog...@mapr.com>
Subject Re: Questions about Drill's multi-thread model
Date Wed, 19 Jul 2017 16:14:05 GMT
Hi Weijie,

There is nothing in Drill’s design that would account for this behavior: each query runs
a separate set of threads from any other query; there is no synchronization among queries.

Did you, perhaps, enable Drill’s ZK-based queueing feature? That would cause later queries
to block waiting for the completion of earlier ones.

Otherwise, perhaps there is an issue with some particular piece of code. What type of file
is being read? In what environment?

Thanks,

- Paul

> On Jul 19, 2017, at 7:20 AM, weijie tong <tongweijie178@gmail.com> wrote:
> 
> Hi there,
>   Our product environment has a situation that if one query was blocked by
> the storage,then all other queries which come later would took long and
> long time to run even they really just need fewer time. At the time ,the
> cluster's load is not too high.
>    I know that every foreman will run in dedicated different  threads. I
> want to know that IO threads model,whether they are shared by different
> foremans' threads. How to explain last scenario's behavior?

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