[Gluster-devel] How to enable FUSE kernel cache about dentry and inode?

[Ravishankar N]

That is strange. I tried the experiment on a volume with a million 
files. The client node's memory usage did grow, as I observed from the 
output of free(1) http://paste.fedoraproject.org/422551/ when I did a `ls`.
-Ravi

On 09/02/2016 07:31 AM, Keiviw wrote:
> Exactly, I mounted the volume in a no-brick node(nodeB), and nodeA was 
> the server. I have set different timeout, but when I excute "ls 
> /mnt/glusterfs(about 3 million small files, in other words, about 3 
> million dentries)", the result was the same, memory usage in nodeB 
> didn't change at all while nodeA's memory usage was changed about 4GB!
>
> 发自 网易邮箱大师 <http://u.163.com/signature>
> On 09/02/2016 09:45, Ravishankar N <mailto:ravishankar at redhat.com> wrote:
>
>     On 09/02/2016 05:42 AM, Keiviw wrote:
>>     Even if I set the attribute-timeout and entry-timeout to
>>     3600s(1h), in the nodeB, it didn't cache any metadata because the
>>     memory usage didn't change. So I was confused that why did the
>>     client not cache dentries and inodes.
>>
>     If you only want to test fuse's caching, I would try mounting the
>     volume on a separate machine (not on the brick node itself),
>     disable all gluster performance xlators, do a find.|xargs stat on
>     the mount 2 times in succession and see what free(1) reports the
>     1st and 2nd time. You could do this experiment with various
>     attr/entry timeout values. Make sure your volume has a lot of
>     small files.
>     -Ravi
>>
>>
>>     在 2016-09-01 16:37:00，"Ravishankar N" <ravishankar at redhat.com>
>>     写道：
>>
>>         On 09/01/2016 01:04 PM, Keiviw wrote:
>>>         Hi,
>>>             I have found that GlusterFS client(mounted by FUSE)
>>>         didn't cache metadata like dentries and inodes. I have
>>>         installed GlusterFS 3.6.0 in nodeA and nodeB, and the brick1
>>>         and brick2 was in nodeA, then in nodeB, I mounted the volume
>>>         to /mnt/glusterfs by FUSE. From my test, I excuted 'ls
>>>         /mnt/glusterfs' in nodeB, and found that the memory didn't
>>>         use at all. Here are my questions:
>>>             1. In fuse kernel, the author set some attributes to
>>>         control the time-out about dentry and inode, in other words,
>>>         the fuse kernel supports metadata cache, but in my test,
>>>         dentries and inodes were not cached. WHY?
>>>             2. Were there some options in GlusterFS mounted to local
>>>         to enable the metadata cache in fuse kernel?
>>>
>>>
>>         You can tweak the attribute-timeout and entry-timeout seconds
>>         while mounting the volume. Default is 1 second for both. 
>>         `man mount.glusterfs` lists various mount options.
>>         -Ravi
>>>
>>>
>>>
>>>         _______________________________________________
>>>         Gluster-devel mailing list
>>>         Gluster-devel at gluster.org
>>>         http://www.gluster.org/mailman/listinfo/gluster-devel
>>
>>
>>
>>
>
>
>

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