This change aims to allow the rook ceph auto-estimation of pg's per
pool.
Placement groups (PGs) are subsets of each logical Ceph pool.
Placement groups perform the function of placing objects
(as a group)into OSDs.Ceph manages data internally at
placement-group granularity: this scales better than would managing individual RADOS objects.
It fixes an issue when using a simplex environment with only 1 osd
it raises a warning alarm where there is too many pg's per pool,
being 250 the limit and when applied there's more than this limit
recommended.
Rook ceph is using the reef version which doesn't require to specify
the pg num at the pool creation[1] while in nautilus version the pg num
specification is a must at the pool creation[2].
Thinking about the different approaches between those versions,
a retro compatibility is also being implemented to preserve the pool
creation in both versions, the self estimate function is preserved.
comparison:
simplex rook ceph without the patch:
POOL PG_NUM
.mgr 32
kube-cephfs-metadata 16
kube-rbd 32
kube-cephfs-data 32
images 64
cinder.backups 64
cinder-volumes 64
simplex rook ceph with the patch:
POOL PG_NUM
kube-rbd 32
.mgr 1
kube-cephfs-metadata 16
kube-cephfs-data 32
images 32
cinder.backups 32
cinder-volumes 32
simplex host ceph before and after the patch:
dumped pgs_brief
kube-rbd (1): 64 PGs
dumped pgs_brief
kube-cephfs-data (2): 64 PGs
dumped pgs_brief
kube-cephfs-metadata (3): 64 PGs
dumped pgs_brief
images (4): 64 PGs
dumped pgs_brief
cinder.backups (5): 64 PGs
dumped pgs_brief
cinder-volumes (6): 64 PGs
Standard rook ceph without the patch:
POOL PG_NUM
kube-rbd 32
.mgr 1
kube-cephfs-metadata 16
kube-cephfs-data 32
images 32
cinder.backups 32
cinder-volumes 32
standard rook ceph with the patch:
POOL PG_NUM
kube-rbd 32
.mgr 1
kube-cephfs-metadata 16
kube-cephfs-data 32
images 32
cinder.backups 32
cinder-volumes 32
Test plan:
simplex:
rook-ceph:
PASS - build openstack
PASS - apply openstack
PASS - create vm's
PASS - ping between vm's
PASS - volume creation/backup creation
PASS - validate alarm for total pg's
host-ceph:
PASS - build openstack
PASS - apply openstack
PASS - create vm's
PASS - ping between vm's
PASS - volume creation/backup creation
PASS - validate alarm for total pg's
standard:
rook-ceph:
PASS - build openstack
PASS - apply openstack
PASS - create vm's
PASS - ping between vm's
PASS - volume creation/backup creation
PASS - validate alarm for total pg's
host-ceph:
PASS - build openstack
PASS - apply openstack
PASS - create vm's
PASS - ping between vm's
PASS - volume creation/backup creation
PASS - validate alarm for total pg's
miscellaneous:
PASS - change pool pg_num through user-overrides
References:
[1] - https://docs.ceph.com/en/reef/rados/operations/placement-groups/#preselecting-pg-num
[2] - https://docs.ceph.com/en/nautilus/rados/operations/placement-groups/#a-preselection-of-pg-num
Closes-Bug: 2122620
Change-Id: I018f7302328c3789864d7f7875fe7d2b4b31f7ee
Signed-off-by: kgoncalv <kayo.goncalvesdacosta@windriver.com>
75278a856c