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

[Brian Foster]

On 01/08/2013 06:42 PM, yongtaofu wrote:
> 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?
> 

No problem. I don't think it should be that difficult to pull back the
keep cache patch to 3.3 if you wanted to, but feel free to ping me if
you have trouble with it.

Note that you probably want to include the following commit as well:

c1fe8b7fd7 mount/fuse: check for fuse inval notify support when
fopen-keep-cache enabled

Brian

> 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.
>>