Welcome! Log In Create A New Profile

Advanced

Re: nginx-0.8.11

All files from this thread

File Name File Size   Posted by Date  
patch-0.8.11.1 447 bytes open | download Igor Sysoev 08/28/2009 Read message
August 29, 2009 05:49AM
On Sat, Aug 29, 2009 at 09:32:50AM +0800, 191919 wrote:

> In Linux, is file aio + directio available when using flv streaming module?

Yes.

> I mean when a transfer is started at an offset which is not multiply of page
> size.

Small unaligned chunks on the start and the end of response are synchronously,
while main response part is read asynchronously.

Linux AIO was developed mainly for database usage. Therefore AIO syscalls
are really asynchronous only if a file is in DIRECTIO mode. Otherwise
the AIO syscalls are currently blocking:
http://axboe.livejournal.com/1718.html

This means that data read by AIO/DIRECTIO will never be cached in VM.

Besides, Linux DIRECTIO mode allows an access aligned to blocksize only.
Unaligned access returns EINVAL. It does not fallback to usual IO as
FreeBSD/Solaris do. Therefore nginx turns DIRECTIO off when it reads
small unaligned chunks on the start and the end of response. These reads
are always blocking, and probably the chunks may be even cached in VM, but
the ending chunk can not preread during previous AIO/DIRECTIO access.

> Will be there a performance increase when serving hundrends of terabytes of
> contents?

I do know about about Linux. I will test it on FreeBSD only.

> 2009/8/28 Igor Sysoev <is@rambler-co.ru>
>
> > Changes with nginx 0.8.11 28 Aug
> > 2009
> >
> > *) Change: directive "gzip_disable msie6" enables gzipping for
> > MSIE 6.0 SV1.
> >
> > *) Feature: file AIO support on FreeBSD and Linux.
> >
> > *) Feature: the "directio_alignment" directive.


--
Igor Sysoev
http://sysoev.ru/en/
Subject Author Posted

nginx-0.8.11

Igor Sysoev August 28, 2009 09:40AM

Re: nginx-0.8.11

Igor Sysoev August 28, 2009 11:28AM

Re: nginx-0.8.11

mike August 28, 2009 12:10PM

Re: nginx-0.8.11

Igor Sysoev August 28, 2009 12:24PM

Re: nginx-0.8.11

mike August 28, 2009 12:39PM

Re: nginx-0.8.11

Igor Sysoev August 28, 2009 12:54PM

Re: nginx-0.8.11

Steve August 28, 2009 04:24PM

Re: nginx-0.8.11

Steve August 28, 2009 05:33PM

Re: nginx-0.8.11 Attachments

Igor Sysoev August 28, 2009 12:57PM

Re: nginx-0.8.11

191919 August 28, 2009 09:32PM

Re: nginx-0.8.11

Igor Sysoev August 29, 2009 05:49AM

Re: nginx-0.8.11

Jeff Waugh August 29, 2009 08:35AM



Sorry, only registered users may post in this forum.

Click here to login

Online Users

Guests: 264
Record Number of Users: 8 on April 13, 2023
Record Number of Guests: 421 on December 02, 2018
Powered by nginx      Powered by FreeBSD      PHP Powered      Powered by MariaDB      ipv6 ready