Ceph BlueStore Compression¶
The Ceph BlueStore storage backend has support for inline compression.
Problem Description¶
The Ceph charms currently do not provide documentation, validation or support for enabling BlueStore inline compression.
Proposed Change¶
Ceph supports configuring compression through per-pool properties and global configuration options. What configuration to use depends on the type of data and the characteristics of the underlying storage devices in use.
To accomodate this we should allow Ceph consuming charms to configure compression on a per-pool basis and have centrally managed defaults for any options not provided.
The following configuration options will be added:
bluestore-compression-algorithm
bluestore-compression-mode
bluestore-compression-required-ratio
bluestore-compression-min-blob-size
bluestore-compression-min-blob-size-hdd
bluestore-compression-min-blob-size-ssd
bluestore-compression-max-blob-size
bluestore-compression-max-blob-size-hdd
bluestore-compression-max-blob-size-ssd
Support will be provided for Ceph Mimic and onwards on Ubuntu 18.04 LTS and onwards.
Alternatives¶
None.
Implementation¶
Assignee(s)¶
- Primary assignee:
fnordahl
Gerrit Topic¶
Use Gerrit topic “ceph-bluestore-compression” for all patches related to this spec.
git-review -t ceph-bluestore-compression
Work Items¶
Extend the Ceph broker API to support providing compression options on pool requests.
Add context that can be used by both consuming and providing charms to map charm configuration options into CephBrokerRq op properties as well as Jinja2 template context data.
Extend the
ceph-clientandceph-rbd-mirrorreactive interfaces to support relaying compression options for pool creation.Add charm configuration options to control global compression defaults to the ceph-osd charm.
Add charm configuration options to control compression on pool creation to the following charms:
glance
cinder-ceph
nova-compute
gnocchi
ceph-iscsi
ceph-radosgw
Add support for copying compression properties on pool mirroring to the ceph-rbd-mirror charm.
Establish a performance baseline and perform benchmark for use in a hyper-converged deployment topology and document results and recommendations.
Repositories¶
No new repositories are required to implement this spec.
Documentation¶
The individual configuration options will get a description that explains basic usage.
A new appendix or section should be added to the deployment-guide to document results of benchmark and recommendations for deployment of Ceph with BlueStore Compression.
Security¶
Apart from enabling code paths in Ceph that was previously not exposed in the charms, there are no security specific considerations for this feature work.
Testing¶
Existing charm gates should be extended to validate the operation of the new charm configuration options.
No special hardware is required to validate the feature.
Dependencies¶
None.
