Re: [ceph-users] CephFS and page cache

2015-10-29 Thread Yan, Zheng
On Thu, Oct 29, 2015 at 4:30 PM, Sage Weil wrote: > On Thu, 29 Oct 2015, Yan, Zheng wrote: >> On Thu, Oct 29, 2015 at 2:21 PM, Gregory Farnum wrote: >> > On Wed, Oct 28, 2015 at 8:38 PM, Yan, Zheng wrote: >> >> On Thu, Oct 29, 2015 at 1:10 AM, Burkhard Linke >> >>> I tried to dig into the ceph-f

Re: [ceph-users] CephFS and page cache

2015-10-29 Thread Burkhard Linke
Hi, On 10/29/2015 09:30 AM, Sage Weil wrote: On Thu, 29 Oct 2015, Yan, Zheng wrote: On Thu, Oct 29, 2015 at 2:21 PM, Gregory Farnum wrote: On Wed, Oct 28, 2015 at 8:38 PM, Yan, Zheng wrote: On Thu, Oct 29, 2015 at 1:10 AM, Burkhard Linke I tried to dig into the ceph-fuse code, but I was un

Re: [ceph-users] CephFS and page cache

2015-10-29 Thread Sage Weil
On Thu, 29 Oct 2015, Yan, Zheng wrote: > On Thu, Oct 29, 2015 at 2:21 PM, Gregory Farnum wrote: > > On Wed, Oct 28, 2015 at 8:38 PM, Yan, Zheng wrote: > >> On Thu, Oct 29, 2015 at 1:10 AM, Burkhard Linke > >>> I tried to dig into the ceph-fuse code, but I was unable to find the > >>> fragment tha

Re: [ceph-users] CephFS and page cache

2015-10-29 Thread Yan, Zheng
On Thu, Oct 29, 2015 at 2:21 PM, Gregory Farnum wrote: > On Wed, Oct 28, 2015 at 8:38 PM, Yan, Zheng wrote: >> On Thu, Oct 29, 2015 at 1:10 AM, Burkhard Linke >>> I tried to dig into the ceph-fuse code, but I was unable to find the >>> fragment that is responsible for flushing the data from the p

Re: [ceph-users] CephFS and page cache

2015-10-28 Thread Gregory Farnum
On Wed, Oct 28, 2015 at 8:38 PM, Yan, Zheng wrote: > On Thu, Oct 29, 2015 at 1:10 AM, Burkhard Linke >> I tried to dig into the ceph-fuse code, but I was unable to find the >> fragment that is responsible for flushing the data from the page cache. >> > > fuse kernel code invalidates page cache on

Re: [ceph-users] CephFS and page cache

2015-10-28 Thread Yan, Zheng
On Thu, Oct 29, 2015 at 1:10 AM, Burkhard Linke wrote: > Hi, > > > On 10/26/2015 01:43 PM, Yan, Zheng wrote: >> >> On Thu, Oct 22, 2015 at 2:55 PM, Burkhard Linke >> wrote: >>> >>> Hi, >>> >>> >>> On 10/22/2015 02:54 AM, Gregory Farnum wrote: On Sun, Oct 18, 2015 at 8:27 PM, Yan, Zheng

Re: [ceph-users] CephFS and page cache

2015-10-28 Thread Burkhard Linke
Hi, On 10/26/2015 01:43 PM, Yan, Zheng wrote: On Thu, Oct 22, 2015 at 2:55 PM, Burkhard Linke wrote: Hi, On 10/22/2015 02:54 AM, Gregory Farnum wrote: On Sun, Oct 18, 2015 at 8:27 PM, Yan, Zheng wrote: On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke wrote: Hi, I've noticed that CephFS

Re: [ceph-users] CephFS and page cache

2015-10-26 Thread Yan, Zheng
On Thu, Oct 22, 2015 at 2:55 PM, Burkhard Linke wrote: > Hi, > > > On 10/22/2015 02:54 AM, Gregory Farnum wrote: >> >> On Sun, Oct 18, 2015 at 8:27 PM, Yan, Zheng wrote: >>> >>> On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke >>> wrote: Hi, I've noticed that CephFS (both ceph

Re: [ceph-users] CephFS and page cache

2015-10-21 Thread Burkhard Linke
Hi, On 10/22/2015 02:54 AM, Gregory Farnum wrote: On Sun, Oct 18, 2015 at 8:27 PM, Yan, Zheng wrote: On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke wrote: Hi, I've noticed that CephFS (both ceph-fuse and kernel client in version 4.2.3) remove files from page cache as soon as they are not i

Re: [ceph-users] CephFS and page cache

2015-10-21 Thread Gregory Farnum
On Sun, Oct 18, 2015 at 8:27 PM, Yan, Zheng wrote: > On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke > wrote: >> Hi, >> >> I've noticed that CephFS (both ceph-fuse and kernel client in version 4.2.3) >> remove files from page cache as soon as they are not in use by a process >> anymore. >> >> Is

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread Brian Kroth
John Spray 2015-10-19 11:34: CephFS supports capabilities to manages access to objects, enforce consistency of data etc. IMHO a sane way to handle the page cache is use a capability to inform the mds about caches objects; as long as no other client claims write access to an object or its metada

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread Stijn De Weirdt
>>> So: the key thing to realise is that caching behaviour is full of >>> tradeoffs, and this is really something that needs to be tunable, so >>> that it can be adapted to the differing needs of different workloads. >>> Having an optional "hold onto caps for N seconds after file close" >>> sounds

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread John Spray
On Mon, Oct 19, 2015 at 12:52 PM, Dan van der Ster wrote: > Your assumption doesn't match what I've seen (in high energy physics > (HEP)). The implicit hint you describe is much more apparent when > clients use object storage APIs like S3 or one of the oodles of > network storage systems we use in

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread John Spray
On Mon, Oct 19, 2015 at 12:52 PM, Dan van der Ster wrote: >> So: the key thing to realise is that caching behaviour is full of >> tradeoffs, and this is really something that needs to be tunable, so >> that it can be adapted to the differing needs of different workloads. >> Having an optional "hol

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread Burkhard Linke
Hi, On 10/19/2015 12:34 PM, John Spray wrote: On Mon, Oct 19, 2015 at 8:59 AM, Burkhard Linke wrote: Hi, On 10/19/2015 05:27 AM, Yan, Zheng wrote: On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke wrote: Hi, I've noticed that CephFS (both ceph-fuse and kernel client in version 4.2.3) remove

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread Dan van der Ster
On Mon, Oct 19, 2015 at 12:34 PM, John Spray wrote: > On Mon, Oct 19, 2015 at 8:59 AM, Burkhard Linke > wrote: >> Hi, >> >> On 10/19/2015 05:27 AM, Yan, Zheng wrote: >>> >>> On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke >>> wrote: Hi, I've noticed that CephFS (both ceph-fus

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread John Spray
On Mon, Oct 19, 2015 at 8:59 AM, Burkhard Linke wrote: > Hi, > > On 10/19/2015 05:27 AM, Yan, Zheng wrote: >> >> On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke >> wrote: >>> >>> Hi, >>> >>> I've noticed that CephFS (both ceph-fuse and kernel client in version >>> 4.2.3) >>> remove files from pag

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread Burkhard Linke
Hi, On 10/19/2015 10:34 AM, Shinobu Kinjo wrote: What kind of applications are you talking about regarding to applications for HPC. Are you talking about like netcdf? Caching is quite necessary for some applications for computation. But it's not always the case. It's not quite related to this

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread Shinobu Kinjo
in your thought using Ceph cluster for HPC computation. Shinobu - Original Message - From: "Burkhard Linke" To: ceph-users@lists.ceph.com Sent: Monday, October 19, 2015 4:59:21 PM Subject: Re: [ceph-users] CephFS and page cache Hi, On 10/19/2015 05:27 AM, Yan, Zheng wrote: >

Re: [ceph-users] CephFS and page cache

2015-10-19 Thread Burkhard Linke
Hi, On 10/19/2015 05:27 AM, Yan, Zheng wrote: On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke wrote: Hi, I've noticed that CephFS (both ceph-fuse and kernel client in version 4.2.3) remove files from page cache as soon as they are not in use by a process anymore. Is this intended behaviour?

Re: [ceph-users] CephFS and page cache

2015-10-18 Thread Yan, Zheng
On Sat, Oct 17, 2015 at 1:42 AM, Burkhard Linke wrote: > Hi, > > I've noticed that CephFS (both ceph-fuse and kernel client in version 4.2.3) > remove files from page cache as soon as they are not in use by a process > anymore. > > Is this intended behaviour? We use CephFS as a replacement for NFS

[ceph-users] CephFS and page cache

2015-10-16 Thread Burkhard Linke
Hi, I've noticed that CephFS (both ceph-fuse and kernel client in version 4.2.3) remove files from page cache as soon as they are not in use by a process anymore. Is this intended behaviour? We use CephFS as a replacement for NFS in our HPC cluster. It should serve large files which are read