Hi Eric,
On Wed, Apr 13, 2016 at 06:37:29PM -0600, Eric Blake wrote:
> Since NBD_OPT_INFO and NBD_OPT_GO are experimental, we still have
> a chance to fix them up before promoting them to stable.
>
> Attempting to reuse NBD_OPT_SERVER as the reply to NBD_OPT_INFO and
> NBD_OPT_GO has a few problems: clients must be prepared to parse
> two different styles of the reply, based on which option request
> the reply is answering. Extending the information to provide even
> more details, like block sizing, is awkward (the only way to do it
> within a single reply is to have multiple length fields that must
> all be consistent; and pre-computing the overall header length may
> be difficult). And requiring the server to parrot back the export
> name is wasteful if the client's name is already in canonical
> form.
Right.
> Solve this by instead making the valid response be a series of reply
> messages (similar to how NBD_OPT_LIST has a series). The series
> is always ended by the new NBD_REP_EXPORT, which is basically a
If we're going to make it a series of messages, I would prefer that the
final message be an NBD_REP_ACK. That way, wire sniffers can always spot
the end of a multi-message reply by way of the ACK at the end, even if
they don't understand the actual multi-message reply.
(no other comments at this point)
--
< ron> I mean, the main *practical* problem with C++, is there's like a dozen
people in the world who think they really understand all of its rules,
and pretty much all of them are just lying to themselves too.
-- #debian-devel, OFTC, 2016-02-12
------------------------------------------------------------------------------
Find and fix application performance issues faster with Applications Manager
Applications Manager provides deep performance insights into multiple tiers of
your business applications. It resolves application problems quickly and
reduces your MTTR. Get your free trial!
https://ad.doubleclick.net/ddm/clk/302982198;130105516;z
_______________________________________________
Nbd-general mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/nbd-general
