Gregory Farnum wrote: : On Mon, Feb 20, 2017 at 6:46 AM, Jan Kasprzak <kas at fi.muni.cz> wrote: : > Hello, world!\n : > : > I have been using CEPH RBD for a year or so as a virtual machine storage : > backend, and I am thinking about moving our another subsystem to CEPH: : > : > The subsystem in question is a simple replicated object storage, : > currently implemented by a custom C code by yours truly. My question : > is whether implementing such a thing on top of a CEPH RADOS pool and librados : > is feasible, and what layout and optimizations would you suggest. : > : > Our object storage indexes object with a numeric ID. The access methods : > involve creating, reading and deleting objects. Objects are never modified : > in place, they are instead deleted and an object with a new ID is created. : > We also keep a hash of an object contents and use it to prevent bit rot : > - the objects are scrubbed periodically, and if a checksum mismatch is : > discovered, the object is restored from another replica. : > : > Here is some statistics from our biggest instance of the object storage: : > : > objects stored: 100_000_000 : > < 1024 bytes: 10_000_000 : > 1k-64k bytes: 80_000_000 : > 64k-4M bytes: 10_000_000 : > 4M-256M bytes: 1_000_000 : >> 256M bytes: 10_000 : > biggest object: 15 GBytes : > : > Would it be feasible to put 100M to 1G objects as a native RADOS objects : > into a single pool? : : This is well outside the object size RADOS is targeted or tested with; : I'd expect issues. You might want to look at libradosstriper from the : requirements you've mentioned. OK, thanks! Is there any documentation for libradosstriper? I am looking for something similar to librados documentation: http://docs.ceph.com/docs/master/rados/api/librados/ Thanks! -Yenya -- | Jan "Yenya" Kasprzak <kas at {fi.muni.cz - work | yenya.net - private}> | | http://www.fi.muni.cz/~kas/ GPG: 4096R/A45477D5 | Assuming that OpenSSL is written as carefully as Wietse's own code, every 1000 lines introduce one additional bug into Postfix." --TLS_README
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