Storing cls and erasure code plugins in a pool

[Loic Dachary <loic@dachary.org>]

[-- Attachment #1: Type: text/plain, Size: 1407 bytes --]

Hi Ceph,

There is a need for a cluster to share code such as cls https://github.com/ceph/ceph/tree/master/src/cls or erasure code plugins https://github.com/ceph/ceph/tree/master/src/erasure-code/.

These plugins could have a life cycle independent of Ceph, as long as they comply to the supported API ( https://github.com/ceph/ceph/blob/master/src/erasure-code/ErasureCodeInterface.h ). For erasure code plugins it currently works this way (or it will as soon as https://github.com/ceph/ceph/pull/2397 is merged):

a) upgrade from Hammer to I* half the OSD nodes. The new I* have new erasure code plugins
b) the MON will refuse to create an erasure coded pool using the new I* plugins, otherwise the Hammer nodes will find themselves unable to participate in the pool

Instead it could work this way:

a) upgrade from Hammer to I* half the OSD nodes. The new I* have new erasure code plugins
b) the new erasure code plugins are uploaded to a "plugins" pool
c) an erasure coded pool is created using a new plugin from I*
d) the Hammer OSD downloads the plugin from the pool and can participate in the pool

It is easier said than done and there are a lot of details to consider. However it not different from maintaining an Operating System that includes shared libraries and the path to do so properly is well known.

Thoughts ?

Cheers

-- 
Loïc Dachary, Artisan Logiciel Libre


[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 263 bytes --]