Re: Nodown/Noout by OSD_ID?

[Sage Weil <sage@newdream.net>]

On Thu, 21 Jan 2016, Xiaoxi Chen wrote:
> Yeah,  mark a whole tree is cool.
> 
> We can do that in API level but in implementation, seems we still need
> to set the flag on OSD level for simplicity. For example, say RackA
> and B are belongs to Row A in crush tree, then if we do:
>      ceph [osdmap? crush? ] set RowA noout
>      ceph [osdmap? crush? ] set RackA noup
>      ceph [osdmap? crush? ] unset RackB noout
> 
> As a result, OSDs in Rack A should be noup+noout, but OSDs in RackB
> should have no flag setted.  The easiest way in my mind might be
> traversal the crush subtree and mark the flag on  vector<uint8_t>
> osd_state for every OSD, uint8_t is just enough for now....but next
> time if we want to have more state will be struggle.

Oh right--that is much simpler!

> 
> #define CEPH_OSD_NOUP     (1<<4)  /* osd cannot be marked up */
> #define CEPH_OSD_NODOWN     (1<<5)  /* osd cannot be marked down */
> #define CEPH_OSD_NOIN     (1<<6)  /* osd cannot be marked in */
> #define CEPH_OSD_NOOUT     (1<<7)  /* osd cannot be marked out */

+1

> The APIs we would like to support are:
> 
> 1. ceph XXX set/unset {crush_subtree_name} {flag}

ceph osd [un]set-osd {osd} {flag}
ceph osd [un]set-subtree {osd} {flag}

(This way we look like 'ceph osd crush reweight-subtree ...'.)

> 2. ceph osd tree will show flag of each OSD (if it has)
> 3. ceph health should show the number of OSD with flags.
> 4. ceph health detail show OSDs with flgas.
> 
> 3) and 4) need to iterate the  vector<uint8_t> osd_state in OSDMap.

Sounds good!
sage