[Gluster-users] Confusing lstat() performance

[Ben Turner]

----- Original Message -----
> From: "Niklas Hambüchen" <mail at nh2.me>
> To: "Ben Turner" <bturner at redhat.com>
> Cc: gluster-users at gluster.org
> Sent: Sunday, September 17, 2017 9:49:10 PM
> Subject: Re: [Gluster-users] Confusing lstat() performance
> 
> Hi Ben,
> 
> do you know if the smallfile benchmark also does interleaved getdents()
> and lstat, which is what I found as being the key difference that
> creates the performance gap (further down this thread)?

I am not sure, you can have a look at it:

https://github.com/bengland2/smallfile


> 
> Also, wouldn't `--threads 8` change the performance numbers by factor 8
> versus the plain `ls` and `rsync` that I did?

Maybe not 8x but it will DEF improve things.  I just recycled what was in my history buffer, I just wanted to illustrate that even though you see the stat calls in the strace application behavior can have a big impact on performance.

> 
> Would you mind running those commands directly/plainly on your cluster
> to confirm or refute my numbers?

I wouldn't mind, but I don't have your dataset.  Thats why I wanted to bring in a perf test tool that we could compare things apples to apples.  What about running on the data that smallfile creates and comparing that?

-b


> 
> Thanks!
>