|
On 04/18/2018 10:35 AM, Artem
Russakovskii wrote:
Hi Ravi,
Could you please expand on how these would help?
By forcing full here, we move the logic from the CPU to
network, thus decreasing CPU utilization, is that right?
Yes, 'diff' employs the rchecksum FOP which does a sha256 checksum
which can consume CPU. So yes it is sort of shifting the load from
CPU to the network. But if your average file size is small, it would
make sense to copy the entire file instead of computing checksums.
This is assuming the CPU and disk utilization are caused
by the differ and not by lstat and other calls or something.
Option:
cluster.data-self-heal-algorithm
Default Value: (null)
Description: Select between "full", "diff". The "full"
algorithm copies the entire file from source to sink. The
"diff" algorithm copies to sink only those blocks whose
checksums don't match with those of source. If no option is
configured the option is chosen dynamically as follows: If
the file does not exist on one of the sinks or empty file
exists or if the source file size is about the same as page
size the entire file will be read and written i.e "full"
algo, otherwise "diff" algo is chosen.
I really have no idea what this means and how/why it would
help. Any more info on this option?
https://github.com/gluster/glusterfs-specs/blob/master/done/GlusterFS%203.8/granular-entry-self-healing.md
should help.
Regards,
Ravi
Option:
cluster.granular-entry-heal
Default Value: no
Description: If this option is enabled, self-heal will
resort to granular way of recording changelogs and doing
entry self-heal.
Thank you.
|
_______________________________________________
Gluster-users mailing list
Gluster-users@xxxxxxxxxxx
http://lists.gluster.org/mailman/listinfo/gluster-users
