impala-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Jim Apple <jbap...@cloudera.com>
Subject Re: Impala query (via JDBC) timeout
Date Fri, 12 Jan 2018 17:40:27 GMT
The Cloudera JDBC driver is not a proper part of Apache Impala, so you
might get better answers here:
http://community.cloudera.com/t5/Interactive-Short-cycle-SQL/bd-p/Impala

One might have a similar question about timeouts in Impala's hs2
interface, which is part of Apache Impala. I don't know much about
that, but https://github.com/apache/impala/commit/ce65b43d47d16840998eb5fab5333695050ac436
and https://issues.apache.org/jira/browse/IMPALA-2248 might help you
out.

On Tue, Jan 2, 2018 at 10:12 AM, Oleksandr Baliev
<aleksanderbalev@gmail.com> wrote:
> Hello,
>
> I'm using impala in conjunction with CDH 5.10.1 and want to have timeouts
> for long running queries. What I've found is:
> 1. Try to QUERY_TIMEOUT_S to close idle queries, as I understand when client
> is closed and don't consume data.
> 2. for jdbc driver (version 2.5.37 or 4.1) there is setQueryTimeout(int).
> which should set xlient side timeout as I understand
> (https://www.cloudera.com/documentation/other/connectors/impala-jdbc/latest/Cloudera-JDBC-Driver-for-Impala-Install-Guide.pdf)
> . It works, but:
> 2.1 when timeout occurs the query is in "waiting to be closed", even if
> close Statement (for Java). And only if close Connection this query will we
> removed from "in_flight_queries".
> 2.2 not sure, haven't checked fully, but seems this timeout can happen only
> when query on earlier stage of executing, maybe when it's executing it's
> okay, but when data is transmitting it cannot be timeout-ed.
> 3. Write some cron script to verify such queries via impalad /queries?json
> and try to close them to do not consume resources.
>
> To be honest I would prefer for now to have some external script which could
> tell if there are any of such queries and react manually/automatically +
> introduce some connection reconnect if there were any of such timeouted
> queries on application level. Also maybe there are some another situations
> when queries are nor closing, so I don't know maybe just reconnect every 20
> minutes :D But this solutions are just workaround and I don't really can
> rely on them since they look a bit fragile.
>
> So the question: is there any good way for the queries via jdbc to be
> gracefully closed by given timeout ?
>
> Will be very thankful for any hints :)
> Sasha
>
>

Mime
View raw message