Core standup would be best. I'll send you an invite. -Sam On Tue, Feb 9, 2016 at 5:24 AM, Igor Fedotov <ifedotov@xxxxxxxxxxxx> wrote: > Ilya, > > please find my comments inline. > > > On 08.02.2016 22:23, Ilya Dryomov wrote: >> >> On Mon, Feb 8, 2016 at 5:34 PM, Igor Fedotov <ifedotov@xxxxxxxxxxxx> >> wrote: >>> >>> Guys, >>> >>> let me summarize what we decided regarding compression support in Ceph >>> during the Dev Meeting last week. >>> >>> Below are possible implementation options, their pros/cons and the >>> conclusion. >>> >>> 1) Add compression support to RGW. >>> Pros/Cons: >>> + Simple >>> + Reduced inter-component traffic >>> - Limited to specific clients >>> - Will conflict with partial read/writes if any appear >>> >>> Alyona Kiseleva from Mirantis (akyseleva@xxxxxxxxxxxx) will start >>> implementing this promptly. You can ask additional questions to her via >>> e-mail or during daily RGW stendups she is planning to attend regularly. >>> >>> 2) Add basic compression support to BlueStore. Basic = "Append only" >>> functionality to be implemented. Specific "append only" hint/flag needs >>> to >>> be introduced for object creation interface. >>> >>> Pros/Cons: >>> + Moderate complexity >>> + Suits for any client/PG backend >>> + Good isolation from other Ceph components >>> - Limited applicability >>> - additional 50-200% CPU load for the cluster since we compress each >>> replica/EC shard independently >>> - no inter-component traffic saving >>> - recovery procedure requires decompress/recompress sequence >> >> This is for EC pools only, right? Can you elaborate on this bullet? > > That's for any pool type. When compression takes place at object store level > and recovery is performed at OSD(PGBackend instance) you need to retrieve an > object replica from the store ( and hence decompress it ) and subsequently > compress it back when saving at a new store . > Contrary having compress/decompress at PGBackend allows to bypass such > decompress/compress overhead. > >>> Mirantis ( me specifically ) will start blueprint/POC creation for this >>> promptly. I'm planning to attend daily RBD syncup regularly to inform on >>> the >>> progress. >> >> Core standup and/or the new EC-overwrite meeting Sam is planning on >> holding is probably a better place for this. > > Where can I find a schedule for these meetings? > >> Thanks, >> >> Ilya > > Regards, > Igor > > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
