beam-user mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Romain Manni-Bucau <rmannibu...@gmail.com>
Subject Re: Reducing database connection with JdbcIO
Date Wed, 14 Mar 2018 19:24:08 GMT
side note: try to do a thread dump on the workers maybe


Romain Manni-Bucau
@rmannibucau <https://twitter.com/rmannibucau> |  Blog
<https://rmannibucau.metawerx.net/> | Old Blog
<http://rmannibucau.wordpress.com> | Github <https://github.com/rmannibucau> |
LinkedIn <https://www.linkedin.com/in/rmannibucau> | Book
<https://www.packtpub.com/application-development/java-ee-8-high-performance>

2018-03-14 20:21 GMT+01:00 Eugene Kirpichov <kirpichov@google.com>:

> "Jdbcio will create for each prepared statement new connection" - this is
> not the case: the connection is created in @Setup and deleted in @Teardown.
> https://github.com/apache/beam/blob/v2.3.0/sdks/java/io/
> jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java#L503
> https://github.com/apache/beam/blob/v2.3.0/sdks/java/io/
> jdbc/src/main/java/org/apache/beam/sdk/io/jdbc/JdbcIO.java#L631
>
> Something else must be going wrong.
>
> On Wed, Mar 14, 2018 at 12:11 PM Aleksandr <aleksandr.vl@gmail.com> wrote:
>
>> Hello, we had similar problem. Current jdbcio will cause alot of
>> connection errors.
>>
>> Typically you have more than one prepared statement. Jdbcio will create
>> for each prepared statement new connection(and close only in teardown) So
>> it is possible that connection will get timeot or in case in case of auto
>> scaling you will get to many connections to sql.
>> Our solution was to create connection pool in setup and get connection
>> and return back to pool in processElement.
>>
>> Best Regards,
>> Aleksandr Gortujev.
>>
>> 14. märts 2018 8:52 PM kirjutas kuupäeval "Jean-Baptiste Onofré" <
>> jb@nanthrax.net>:
>>
>> Agree especially using the current JdbcIO impl that creates connection in
>> the @Setup. Or it means that @Teardown is never called ?
>>
>> Regards
>> JB
>> Le 14 mars 2018, à 11:40, Eugene Kirpichov <kirpichov@google.com> a
>> écrit:
>>>
>>> Hi Derek - could you explain where does the "3000 connections" number
>>> come from, i.e. how did you measure it? It's weird that 5-6 workers would
>>> use 3000 connections.
>>>
>>> On Wed, Mar 14, 2018 at 3:50 AM Derek Chan <derekcsy@gmail.com> wrote:
>>>
>>>> Hi,
>>>>
>>>> We are new to Beam and need some help.
>>>>
>>>> We are working on a flow to ingest events and writes the aggregated
>>>> counts to a database. The input rate is rather low (~2000 message per
>>>> sec), but the processing is relatively heavy, that we need to scale out
>>>> to 5~6 nodes. The output (via JDBC) is aggregated, so the volume is also
>>>> low. But because of the number of workers, it keeps 3000 connections to
>>>> the database and it keeps hitting the database connection limits.
>>>>
>>>> Is there a way that we can reduce the concurrency only at the output
>>>> stage? (In Spark we would have done a repartition/coalesce).
>>>>
>>>> And, if it matters, we are using Apache Beam 2.2 via Scio, on Google
>>>> Dataflow.
>>>>
>>>> Thank you in advance!
>>>>
>>>>
>>>>
>>>>
>>

Mime
View raw message