& # 39; sortbitwise & # 39; What does this mean

problem

flag sortbitwise What does it mean ceph, in the version of Jewel can see more of the flags

[root@lab8106 current]
    cluster ffe7a8db-c671-4b45-a784-ddb41e633905
     health HEALTH_OK
     monmap e1: 1 mons at {lab8106=192.168.8.106:6789/0}
            election epoch 4, quorum 0 lab8106
      fsmap e4: 1/1/1 up {0=lab8106=up:active}
     osdmap e132: 8 osds: 8 up, 8 in
            flags sortbitwise
      pgmap v206294: 201 pgs, 5 pools, 4684 MB data, 1214 objects
            9669 MB used, 2216 GB / 2226 GB avail
                 201 active+clean

Relevant information found

After upgrading, users should set the ‘sortbitwise’ flag to enable the new internal object sort order: ceph osd set sortbitwise
This flag is important for the new object enumeration API and for new backends like BlueStore.

From Ceph release notes

commit 383185bfbae74797cdb44f50b4bf651422800ff1
Author: Sage Weil [email protected]
Date: Fri Aug 7 16:14:09 2015 -0400
mon/OSDMonitor: osd set/unset sortbitwise
Add monitor command to flip the switch on the OSD hobject_t sort
order.

From git

First appear in the source code:

From git

Related github issue: https://github.com/ceph/ceph/pull/4919/commits

Preliminary conclusions: a change sortbitwise internal sorting algorithm of the reason is because you want to expose some of the pre-jewel-compatible version in the new version should remain open.

Reprinted from the above blog: the What 'sortbitwise' Flag means in Ceph?

Red Hat official answer

If you use the dev version Infernalis or Jewel versions of Ceph LTS version is still under development, you will see this flag is enabled by default in ceph status output
This flag sortbitwise introduced in version Infernalis
This flag is upstream in this version submitted commit 968261b11ac30622c0606d1e2ddf422009e7d330

Ceph download the source code, enter the source directory

[root@lab8106 all]
commit 968261b11ac30622c0606d1e2ddf422009e7d330
Author: Sage Weil <[email protected]>
Date:   Fri Aug 7 16:01:12 2015 -0400

    osd/OSDMap: add a SORTBITWISE OSDMap flag

    This flag will indicate that hobject_t's shall hence-forth be
    sorted in a bitwise fashion.

    Signed-off-by: Sage Weil <[email protected]>

As we described in a given submission of the above mentioned, the flag will be bitwise fashion show sort of way hobject_t of.
Now it means now objects to be sorted in OSDs bit mode, and this flag defaults in Infernalis and Jewel-release version is enabled.

to sum up

For now this is sort of a change in the underlying algorithm, the upper layer is unclear what changes can be seen, in short, that it is enabled by default on the line, not to change it it

change log

Why	Who	When
create	Wuhan - operation and maintenance - mill slag	2017-01-12

原文引用大专栏 https://www.dazhuanlan.com/2019/08/27/5d64c777b7014/