RADOS doesn't store a list of objects. The RADOS Gateway uses a separate data format on top of objects stored in RADOS, and it keeps a per-user list of buckets and a per-bucket index of objects as "omap" objects in the OSDs (which ultimately end up in a leveldb store). A bucket index is currently a single object (stored on one OSD), so that is a performance (and, much later, storage) bottleneck that you can run into with extremely large buckets that see enough traffic. We don't have a precise number (it depends in large part on how powerful your OSDs are) but it's somewhere in the many millions of objects. -Greg Software Engineer #42 @ http://inktank.com | http://ceph.com On Monday, March 11, 2013 at 4:28 PM, Rustam Aliyev wrote: > Thanks Sam, > > That's great. I'm trying to understand a bit of RADOS internals and I > went through architecture wiki. Yet unclear about some points. > > Where does RADOS store the list of objects (object metadata)? According > to RADOSGW docs S3 bucket listing is available, so it must be stored > somewhere. > > Thanks, > Rustam. > > On 11/03/2013 20:28, Sam Lang wrote: > > On Fri, Mar 8, 2013 at 9:57 PM, Rustam Aliyev <rustam.lists@xxxxxxx (mailto:rustam.lists@xxxxxxx)> wrote: > > > Hi, > > > > > > We need to store ~500M of small files (<1MB) and we were looking to RadosGW > > > solution. We expect about 20 ops/sec (read+write). I'm trying to understand > > > how Monitoring nodes store Crush maps and what are the limitations. > > > > > > For instance, is there any recommended max number of objects per Monitoring > > > node? Does adding more monitoring nodes will help to scale number of small > > > files and iops (assuming that OSDs not a bottleneck)? > > > > > > No, the number of objects is unrelated to the monitors, so 3 monitors > > should suffice in your case. > > -sam > > > > > Many thanks, > > > Rustam. > > > _______________________________________________ > > > ceph-users mailing list > > > ceph-users@xxxxxxxxxxxxxx (mailto:ceph-users@xxxxxxxxxxxxxx) > > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx (mailto:ceph-users@xxxxxxxxxxxxxx) > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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