From: Gregory Farnum <gfarnum@redhat.com>
To: "Xinze Chi (信泽)" <xmdxcxz@gmail.com>
Cc: "ceph-devel@vger.kernel.org" <ceph-devel@vger.kernel.org>
Subject: Re: objecter incremental osdmap crc check
Date: Wed, 3 Feb 2016 09:00:08 -0800 [thread overview]
Message-ID: <CAJ4mKGYLs1nKOnU24s5Xh3SBPeCf=RUd-=hky02-q2FYPwf3Fw@mail.gmail.com> (raw)
In-Reply-To: <CANE=7sVATveDWRxv_X=jprzcJW50ssu0zojQgHLOUDP5aGF5Pw@mail.gmail.com>
On Wed, Feb 3, 2016 at 5:54 AM, Xinze Chi (信泽) <xmdxcxz@gmail.com> wrote:
> hi, all:
>
> When osd update the osdmap, it would apply the
> OSDMap::Incremental and get the crc for the new osdmap. If the crc is
> not the same as define in Incremental osd would request the full
> osdmap. I think the logic is quite well.
>
> But in the client, the objecter do not check the crc. I do not
> know why not client do the same logic as osd.
>
> Could anyone explain this? Thanks.
Two things:
1) The client doesn't necessarily have the full OSDMap that the OSDs
do, so the CRC won't match. (You can see this in the encoding family
of functions; there are sections which are server-only.) I suppose the
monitors could include a client-only CRC as well...
2) Nobody bothered since it seemed less important for "ephemeral"
clients versus OSDs that persist their maps and share them with peers.
-Greg
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next prev parent reply other threads:[~2016-02-03 17:00 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-02-03 13:54 objecter incremental osdmap crc check Xinze Chi (信泽)
2016-02-03 17:00 ` Gregory Farnum [this message]
2016-02-04 11:25 ` Xinze Chi (信泽)
2016-02-04 15:22 ` Gregory Farnum
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