Re: PostgreSQL Read IOPS limit per connection

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Justin,
Thanks for the quick response, I'll check it out.

Happy holidays,
Haroldo Kerry

On Thu, Dec 27, 2018 at 2:55 PM Justin Pryzby <pryzby@xxxxxxxxxxxxx> wrote:
On Thu, Dec 27, 2018 at 02:44:55PM -0200, Haroldo Kerry wrote:
> PostgreSQL 9.6.10 on x86_64-pc-linux-gnu (Debian 9.6.10-1.pgdg80+1),

> Connected to SAN: Dell Compellent SC2020, with 7 x Samsung PM1633 SSDs
> https://www.samsung.com/us/labs/pdfs/collateral/pm1633-prodoverview-2015.pdf,
> RAID10+RAID5 configuration, 8GB Cache, read-write battery backed cache
> enabled, connected via dedicated iSCSI switches and dedicated Ethernet
> ports, in link aggregation mode (2x1Gbps max bandwidth).

> I’m trying to figure out if PostgreSQL (PG) has some inherent limit on IOPS
> per connection.

postgres uses one server backend per client.

> We tried to increase effective_io_size from 1 to 30, to no effect on
> multiple tests.

https://www.postgresql.org/docs/current/runtime-config-resource.html#RUNTIME-CONFIG-RESOURCE-ASYNC-BEHAVIOR
=> "Currently, this setting only affects bitmap heap scans."

> Is this some inherent limitation of PG or am I misunderstanding something?

It is a hsitoric limitation, but nowadays there's parallel query, which uses
2ndary "backend worker" processes.

It's supported in v9.6 but much more versatile in v10 and v11.

Justin


--

Haroldo Kerry

CTO/COO

Rua do Rócio, 220, 7° andar, conjunto 72

São Paulo – SP / CEP 04552-000

hkerry@xxxxxxxxxxxxx

www.callix.com.br


[Postgresql General]     [Postgresql PHP]     [PHP Users]     [PHP Home]     [PHP on Windows]     [Kernel Newbies]     [PHP Classes]     [PHP Books]     [PHP Databases]     [Yosemite]

  Powered by Linux