| From: | KONDO Mitsumasa <kondo(dot)mitsumasa(at)lab(dot)ntt(dot)co(dot)jp> |
|---|---|
| To: | Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us> |
| Cc: | Andres Freund <andres(at)2ndquadrant(dot)com>, Amit Langote <amitlangote09(at)gmail(dot)com>, PostgreSQL-development <pgsql-hackers(at)postgresql(dot)org>, Postgres General <pgsql-general(at)postgresql(dot)org> |
| Subject: | Re: [GENERAL] Bottlenecks with large number of relation segment files |
| Date: | 2013-08-06 10:19:41 |
| Message-ID: | 5200CDBD.2020405@lab.ntt.co.jp |
| Views: | Raw Message | Whole Thread | Download mbox | Resend email |
| Thread: | |
| Lists: | pgsql-general pgsql-hackers |
(2013/08/05 21:23), Tom Lane wrote:
> Andres Freund <andres(at)2ndquadrant(dot)com> writes:
>> ... Also, there are global
>> limits to the amount of filehandles that can simultaneously opened on a
>> system.
>
> Yeah. Raising max_files_per_process puts you at serious risk that
> everything else on the box will start falling over for lack of available
> FD slots.
Is it Really? When I use hadoop like NOSQL storage, I set large number of FD.
Actually, Hadoop Wiki is writing following.
http://wiki.apache.org/hadoop/TooManyOpenFiles
> Too Many Open Files
>
> You can see this on Linux machines in client-side applications, server code or even in test runs.
> It is caused by per-process limits on the number of files that a single user/process can have open, which was introduced in the 2.6.27 kernel. The default value, 128, was chosen because "that should be enough".
>
> In Hadoop, it isn't.
~
> ulimit -n 8192
Regards,
--
Mitsumasa KONDO
NTT Open Source Software Center
| From | Date | Subject | |
|---|---|---|---|
| Next Message | KONDO Mitsumasa | 2013-08-06 10:28:57 | Re: Bottlenecks with large number of relation segment files |
| Previous Message | KONDO Mitsumasa | 2013-08-06 10:09:06 | Re: [GENERAL] Bottlenecks with large number of relation segment files |
| From | Date | Subject | |
|---|---|---|---|
| Next Message | KONDO Mitsumasa | 2013-08-06 10:28:57 | Re: Bottlenecks with large number of relation segment files |
| Previous Message | KONDO Mitsumasa | 2013-08-06 10:09:06 | Re: [GENERAL] Bottlenecks with large number of relation segment files |