Actions
Osd - tiering - new cache modes¶
Summary¶
Add read-forward and read-proxy cache modes
Owners¶
- Sage Weil (Inktank)
Interested Parties¶
- Name (Affiliation)
- Name (Affiliation)
- Name
Current Status¶
The current forward cache mode will process the request locally if it exists in the tier and forward anything else.
Detailed Description¶
There are a couple other modes that make sense:- read-forward: if the op is a read and we miss in the cache tier, forward the request.
- this is useful if the base tier is similar fast for reads to the cache tier but we have asymetric write performance or endurance
- read-proxy: proxy the read on miss
- like read-forward, do not promote when there is a miss. but, instead of replying with a redirect and making the client do the read, just do the read on their behalf. this improves latency for certain configurations.
Work items¶
Coding tasks¶
- osd: add read-forward mode
- osd: add read-proxy mode
- mon: add new modes to cachemode command set
- qa: add tests to the rados suite to exercise the different cache modes
Documentation tasks¶
- doc: add docs that describe new (and old!) modes and their behaviors, along with examples of when they would be useful
Updated by Jessica Mack almost 9 years ago · 1 revisions