Re: Horizontal scalability/sharding - Mailing list pgsql-hackers

From Amit Kapila
Subject Re: Horizontal scalability/sharding
Date
Msg-id CAA4eK1KNNbn+a8DM+6FBSjV5J3cjb4e3uE2iGDOuqqqzvnaSMg@mail.gmail.com
Whole thread Raw
In response to Re: Horizontal scalability/sharding  (Pavan Deolasee <pavan.deolasee@gmail.com>)
Responses Re: Horizontal scalability/sharding  (Etsuro Fujita <fujita.etsuro@lab.ntt.co.jp>)
List pgsql-hackers
On Wed, Sep 2, 2015 at 4:19 PM, Pavan Deolasee <pavan.deolasee@gmail.com> wrote:
> On Wed, Sep 2, 2015 at 3:55 PM, Amit Langote <Langote_Amit_f8@lab.ntt.co.jp> wrote:
>>
>> On 2015-09-02 PM 06:41, Amit Langote wrote:
>>
>> Which, I now realize, is not the worry Amit Kapila's expresses.
>>
>> The deadlock was *indeed detected* in this case, with all the locks in the
>> same PG instance. In a sharded environment with multiple PG instances,
>> that becomes tricky. DLM (distributed lock manager/deadlock detector)
>> seems indeed necessary as Amit K. suspects.
>>
>
> Right. XC/XL did not address this issue and they rely on statement timeouts to break distributed deadlocks.
>

I think that will be difficult for application to decide and then it
needs to decide the same for all statements which is tricky because
different statements could take different time.  I think it is better to
have solution for this problem and deadlock should be detected.


With Regards,
Amit Kapila.
EnterpriseDB: http://www.enterprisedb.com

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