Re: Bitrot: Time of signing depending on the file size???

[Amudhan P <amudhan83@xxxxxxxxx>]

Hi David,

Once after file write completes (fd closed) bitrot process will wait for 120 seconds and if there no fd is opened for the file it will trigger the signer process.

considering the signer, process start and end time file read speed was < 250KB/s.

To increase bitrot signer read speed need to modify the bitrot source file.

regards

Amudhan

On Fri, Mar 1, 2019 at 5:49 PM David Spisla <spisla80@xxxxxxxxx> wrote:

Hello Amudhan,

What does exactly mean "it takes < 250KB/s"?

I figured out this discussion between you and Kotresh: https://lists.gluster.org/pipermail/gluster-users/2016-September/028354.html

Kotresh mentioned there that the problem is because for some files fd process are still up in the brick process list. Bitrot signer can only sign a file if the fd is closed. And according to my observations it seems to be that as bigger a file is as longer the fd is still up. I could verify this with a 500MiB file and some smaller files. After a specific time only the fd for the 500MiB was up and the file still had no signature, for the smaller files there were no fds and they already had a signature.

Does anybody know what is the reason for this? For me it looks loke a bug.

Regards

David

Am Fr., 1. März 2019 um 08:58 Uhr schrieb Amudhan P <amudhan83@xxxxxxxxx>:

Hi David,

I have also tested the bitrot signature process by default it takes < 250 KB/s.

regards

Amudhan P

On Fri, Mar 1, 2019 at 1:19 PM David Spisla <spisla80@xxxxxxxxx> wrote:

Hello folks,

I did some observations concerning the bitrot daemon. It seems to be that the bitrot signer is signing files depending on file size. I copied files with different sizes into a volume and I was wonderung because the files get their signature not the same time (I keep the expiry time default with 120). Here are some examples:

300 KB file ~2-3 m
70 MB file ~ 40 m
115 MB file ~ 1 Sh

800 MB file ~ 4,5 h

What is the expected behaviour here?

Why does it take so long to sign a 800MB file?

What about 500GB or 1TB?

Is there a way to speed up the sign process?

My ambition is to understand this observation

Regards

David Spisla

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