h Roy; ??; ceph-devel@vger.kernel.org; Chen, Xiaoxi
Subject: Re: puzzled with the design pattern of ceph journal, really ruining
performance
FWIW, the journal will coalesce writes quickly when there are many
concurrent 4k client writes. Once you hit around 8 4k IOs per OSD,
the journal will start coale
ceph-devel-ow...@vger.kernel.org
[mailto:ceph-devel-ow...@vger.kernel.org] On Behalf Of Alexandre DERUMIER
Sent: Thursday, September 18, 2014 5:13 AM
To: Mark Nelson
Cc: Somnath Roy; ??; ceph-devel@vger.kernel.org; Chen, Xiaoxi
Subject: Re: puzzled with the design pattern of ceph journal, really ruinin
or coalescing write (client side), then
help also the journal ?
- Mail original -
De: "Mark Nelson"
À: "Alexandre DERUMIER" , "Xiaoxi Chen"
Cc: "Somnath Roy" , "??" ,
ceph-devel@vger.kernel.org
Envoyé: Mercredi 17 Septembre 2014 17:01:06
hen"
À: "Somnath Roy" , "??" ,
ceph-devel@vger.kernel.org
Envoyé: Mercredi 17 Septembre 2014 09:59:37
Objet: RE: puzzled with the design pattern of ceph journal, really ruining
performance
Hi Nicheal,
1. The main purpose of journal is provide transaction semantics (prevent
parti
b --sync=1
#bw=41794KB/s, iops=10448
- Mail original -
De: "Xiaoxi Chen"
À: "Somnath Roy" , "??" ,
ceph-devel@vger.kernel.org
Envoyé: Mercredi 17 Septembre 2014 09:59:37
Objet: RE: puzzled with the design pattern of ceph journal, really ruining
performan
devel@vger.kernel.org
Subject: RE: puzzled with the design pattern of ceph journal, really ruining
performance
Hi Nicheal,
Not only recovery , IMHO the main purpose of ceph journal is to support
transaction semantics since XFS doesn't have that. I guess it can't be achieved
with
[mailto:ceph-devel-ow...@vger.kernel.org] On Behalf Of ??
Sent: Tuesday, September 16, 2014 11:29 PM
To: ceph-devel@vger.kernel.org
Subject: puzzled with the design pattern of ceph journal, really ruining
performance
Hi, guys
I analyze the architecture of the ceph souce code.
I know that, in
Hi, guys
I analyze the architecture of the ceph souce code.
I know that, in order to keep journal atomic and consistent, the
journal write mode should be set with O_DSYNC or called fdatasync()
system call after every write operation. However, this kind of
operation is really killing the performan
