question Why Impala JDBC close() and execute() with synchronized in Support Questions

Why Impala JDBC close() and execute() with synchronized

hqbhoho — Tue, 21 Mar 2023 13:50:22 GMT

I use Impala JDBC to query, I find close() and execute() with synchronized. So if I invoke close() in other thread will wait execute() ，because if execute() is running，close() will blocked waiting for lock. So I should invoke cancal() before close() to avoid block?

Re: Why Impala JDBC close() and execute() with synchronized

DianaTorres — Tue, 21 Mar 2023 16:45:53 GMT

@hqbhoho Welcome to the Cloudera Community!

To help you get the best possible solution, I have tagged our Impala experts @mszurap and @bbreak who may be able to assist you further.

Please keep us updated on your post, and we hope you find a satisfactory solution to your query.

Re: Why Impala JDBC close() and execute() with synchronized

bbreak — Tue, 21 Mar 2023 16:54:24 GMT

@hqbhoho , if the query is executing, it probably makes sense to cancel it before you try to call close.

Re: Why Impala JDBC close() and execute() with synchronized

hqbhoho — Wed, 22 Mar 2023 01:06:29 GMT

@bbreak thanks, I will try. In my case, I wan't call close to close a statement. execute and close will call in different thread. So Why synchronized both close and execute? Now close will not work before execute

complete

Re: Why Impala JDBC close() and execute() with synchronized

bbreak — Mon, 27 Mar 2023 20:40:24 GMT

Closing the connection while the query is still executing is generally not good practice. Think of it as taking ownership for the query you've executed, sort of like turning the lights off before you leave a room. If you're going to close the session (leave the room), you need to first cancel the query that's consuming resources (turn off the lights you turned on). The normal expectation is that an executing query will have an associated active session.