[Gluster-users] help me, glusterfs 3.3 doen't support fopen-keep-cache?

[yongtaofu]

Hi brian
Thank you very much for your info.
I have already tried io-cache it helps a little but it can't compete with page cache. 
BTW what's the effort if I want to back port fopen keep cache to 3.3?

发自我的 iPhone

在 2013-1-8，23:21，Brian Foster <bfoster at redhat.com> 写道：

> On 01/08/2013 09:49 AM, 符永涛 wrote:
>> Dear gluster experts,
>> 
>> I search through glusterfs 3.3 source tree and can't find any fuse
>> open option FOPEN_KEEP_CACHE related code. Does this mean that
>> glusterfs 3.3 doen't support fuse keep cache feature? However I did
>> find keep cache code in mainline. My question is:
> 
> It appears that keep cache support is not included in the 3.3 release.
> You can build from the latest git repo to try it:
> 
> 32ffb79f fuse/md-cache: add support for the 'fopen-keep-cache' mount option
> 
>> 1 does glusterfs 3.3 support page cache?
> 
> Page cache interaction is primarily a function of fuse. The current
> behavior is that writes are synchronous to the fuse filesystem, reads
> are potentially served from page cache, and file open operations
> invalidate the entire mapping for a file.
> 
> The FOPEN_KEEP_CACHE fuse init option disables the latter behavior. In
> turn, gluster detects whether changes have occurred in the file remotely
> and nudges fuse to invalidate the file cache on-demand. There is also
> upstream fuse work in progress to support writeback cache behavior[1].
> 
>> 2 if not what is the best practice to improve performance if a file is
>> frequently accessed by read especially through random access fops.
> 
> I would suggest to experiment with the tunables in the io-cache
> translator (xlators/performance/io-cache/src/io-cache.c), such as
> priority, cache-timeout and cache-size.
> 
>> 3 does glusterfs 3.4 support page cache, if supported how to enable it
>> through mount option?
> 
> I would hope that it will at least include the keep cache support. Use
> the fopen-keep-cache mount option on latest gluster to try it out.
> 
> Brian
> 
> [1] - http://comments.gmane.org/gmane.comp.file-systems.fuse.devel/12266
> 
>> Thank you very much.
>