[AFS3-std] Re: abort packet format

Andrew Deason adeason@sinenomine.net
Tue, 8 Mar 2011 22:04:47 -0600


On Tue, 08 Mar 2011 20:48:55 -0500
Jason Edgecombe <jason@rampaginggeek.com> wrote:

> ok, so is there any unallocated space in the payload? Does adding this
> require a new RPC or something?

It's at a lower level than RPCs. But it'll require some standards doc
and all that, I expect. The payload is variable; I expect we have as
much space to work with as will fit in a single packet.

>>> On 03/07/2011 11:28 AM, Derrick Brashear wrote:
>>>> right now, abort packets have a payload of "the error". anything
>>>> beyond the 32 bit error in the payload is undefined.
>>>>
>>>> comments on exploring a way to ship additional data, like a reason
>>>> in the event of e.g. delayed abort (so clients can be notified
>>>> they're being throttled)?

Well, just make the next 32 bits a "reason" code? While we could try
bit-packing stuff or something, it's hard to see the rationale without
having an idea of what we might also want to put in there in the future.

Or hmm, is a bitfield more appropriate? Allocate a bit for "you're being
throttled"? We could just say the 33rd bit represents a throttling flag,
and the next 7 (or 31; but I'm assuming we can include individual bytes)
must be 0 until we define them to mean something.

All known implementations will ignore anything beyond the first 32 bits,
right?

-- 
Andrew Deason
adeason@sinenomine.net