On Wed, Jul 31, 2019 at 1:32 AM nokia ceph <nokiacephusers@xxxxxxxxx> wrote:
Hi Greg,We were trying to implement this however having issues in assigning the destination object name with this api.There is a rados command "rados -p <poolname> cp <src obj> <dst obj>" , is there any librados api equivalent to this ?
The copyfrom operation, like all other ops, is directed to a specific object. The object you run it on is the destination; it copies the specified “src” object into itself.
-Greg
Thanks,MuthuOn Fri, Jul 5, 2019 at 4:00 PM nokia ceph <nokiacephusers@xxxxxxxxx> wrote:Thank you Greg, we will try this out .Thanks,MuthuOn Wed, Jul 3, 2019 at 11:12 PM Gregory Farnum <gfarnum@xxxxxxxxxx> wrote:Well, the RADOS interface doesn't have a great deal of documentation
so I don't know if I can point you at much.
But if you look at Objecter.h, you see that the ObjectOperation has
this function:
void copy_from(object_t src, snapid_t snapid, object_locator_t
src_oloc, version_t src_version, unsigned flags, unsigned
src_fadvise_flags)
src: the object to copy from
snapid: if you want to copy a specific snap instead of HEAD
src_oloc: the object locator for the object
src_version: the version of the object to copy from (helps identify if
it was updated in the meantime)
flags: probably don't want to set these, but see
PrimaryLogPG::_copy_some for the choices
src_fadvise_flags: these are the fadvise flags we have in various
places that let you specify things like not to cache the data.
Probably leave them unset.
-Greg
On Wed, Jul 3, 2019 at 2:47 AM nokia ceph <nokiacephusers@xxxxxxxxx> wrote:
>
> Hi Greg,
>
> Can you please share the api details for COPY_FROM or any reference document?
>
> Thanks ,
> Muthu
>
> On Wed, Jul 3, 2019 at 4:12 AM Brad Hubbard <bhubbard@xxxxxxxxxx> wrote:
>>
>> On Wed, Jul 3, 2019 at 4:25 AM Gregory Farnum <gfarnum@xxxxxxxxxx> wrote:
>> >
>> > I'm not sure how or why you'd get an object class involved in doing
>> > this in the normal course of affairs.
>> >
>> > There's a copy_from op that a client can send and which copies an
>> > object from another OSD into the target object. That's probably the
>> > primitive you want to build on. Note that the OSD doesn't do much
>>
>> Argh! yes, good idea. We really should document that!
>>
>> > consistency checking (it validates that the object version matches an
>> > input, but if they don't it just returns an error) so the client
>> > application is responsible for any locking needed.
>> > -Greg
>> >
>> > On Tue, Jul 2, 2019 at 3:49 AM Brad Hubbard <bhubbard@xxxxxxxxxx> wrote:
>> > >
>> > > Yes, this should be possible using an object class which is also a
>> > > RADOS client (via the RADOS API). You'll still have some client
>> > > traffic as the machine running the object class will still need to
>> > > connect to the relevant primary osd and send the write (presumably in
>> > > some situations though this will be the same machine).
>> > >
>> > > On Tue, Jul 2, 2019 at 4:08 PM nokia ceph <nokiacephusers@xxxxxxxxx> wrote:
>> > > >
>> > > > Hi Brett,
>> > > >
>> > > > I think I was wrong here in the requirement description. It is not about data replication , we need same content stored in different object/name.
>> > > > We store video contents inside the ceph cluster. And our new requirement is we need to store same content for different users , hence need same content in different object name . if client sends write request for object x and sets number of copies as 100, then cluster has to clone 100 copies of object x and store it as object x1, objectx2,etc. Currently this is done in the client side where objectx1, object x2...objectx100 are cloned inside the client and write request sent for all 100 objects which we want to avoid to reduce network consumption.
>> > > >
>> > > > Similar usecases are rbd snapshot , radosgw copy .
>> > > >
>> > > > Is this possible in object class ?
>> > > >
>> > > > thanks,
>> > > > Muthu
>> > > >
>> > > >
>> > > > On Mon, Jul 1, 2019 at 7:58 PM Brett Chancellor <bchancellor@xxxxxxxxxxxxxx> wrote:
>> > > >>
>> > > >> Ceph already does this by default. For each replicated pool, you can set the 'size' which is the number of copies you want Ceph to maintain. The accepted norm for replicas is 3, but you can set it higher if you want to incur the performance penalty.
>> > > >>
>> > > >> On Mon, Jul 1, 2019, 6:01 AM nokia ceph <nokiacephusers@xxxxxxxxx> wrote:
>> > > >>>
>> > > >>> Hi Brad,
>> > > >>>
>> > > >>> Thank you for your response , and we will check this video as well.
>> > > >>> Our requirement is while writing an object into the cluster , if we can provide number of copies to be made , the network consumption between client and cluster will be only for one object write. However , the cluster will clone/copy multiple objects and stores inside the cluster.
>> > > >>>
>> > > >>> Thanks,
>> > > >>> Muthu
>> > > >>>
>> > > >>> On Fri, Jun 28, 2019 at 9:23 AM Brad Hubbard <bhubbard@xxxxxxxxxx> wrote:
>> > > >>>>
>> > > >>>> On Thu, Jun 27, 2019 at 8:58 PM nokia ceph <nokiacephusers@xxxxxxxxx> wrote:
>> > > >>>> >
>> > > >>>> > Hi Team,
>> > > >>>> >
>> > > >>>> > We have a requirement to create multiple copies of an object and currently we are handling it in client side to write as separate objects and this causes huge network traffic between client and cluster.
>> > > >>>> > Is there possibility of cloning an object to multiple copies using librados api?
>> > > >>>> > Please share the document details if it is feasible.
>> > > >>>>
>> > > >>>> It may be possible to use an object class to accomplish what you want
>> > > >>>> to achieve but the more we understand what you are trying to do, the
>> > > >>>> better the advice we can offer (at the moment your description sounds
>> > > >>>> like replication which is already part of RADOS as you know).
>> > > >>>>
>> > > >>>> More on object classes from Cephalocon Barcelona in May this year:
>> > > >>>> https://www.youtube.com/watch?v=EVrP9MXiiuU
>> > > >>>>
>> > > >>>> >
>> > > >>>> > Thanks,
>> > > >>>> > Muthu
>> > > >>>> > _______________________________________________
>> > > >>>> > ceph-users mailing list
>> > > >>>> > ceph-users@xxxxxxxxxxxxxx
>> > > >>>> > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>> > > >>>>
>> > > >>>>
>> > > >>>>
>> > > >>>> --
>> > > >>>> Cheers,
>> > > >>>> Brad
>> > > >>>
>> > > >>> _______________________________________________
>> > > >>> ceph-users mailing list
>> > > >>> ceph-users@xxxxxxxxxxxxxx
>> > > >>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>> > >
>> > >
>> > >
>> > > --
>> > > Cheers,
>> > > Brad
>> > > _______________________________________________
>> > > ceph-users mailing list
>> > > ceph-users@xxxxxxxxxxxxxx
>> > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
>>
>>
>>
>> --
>> Cheers,
>> Brad
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