MPUB protocol spec

[mreiferson]

Looks like the protocol spec for MPUB does not match the implementation. I suspect the implementation is the up to date one, (so you can have a max request size). But I wanted to double check.

-Dustin

[mreiferson]

@dustismo thanks...

I just reviewed the protocol spec - where are you finding it differ from the implementation in master?

there were some changes to MPUB since the 0.2.16 release, specifically making it atomic in #135... want to make sure I didn't miss something...

[dustismo]

My reading of the spec is that a message should be of the form (to publish 3 messages to topic 'topic1'):

MPUB topic1 3\n
[messageSize1][message1]
[messageSize2][message2]
[messageSize3][message3]

The implementation appears to be:

MPUB topic1\n
[totalBodySize]
[messageSize1][message1]
[messageSize2][message2]
[messageSize3][message3]

[dustismo]

Actually implementation looks like:

MPUB topic1\n
[totalMessages][totalBodySize]
[messageSize1][message1]
[messageSize2][message2]
[messageSize3][message3]

[dustismo]

If it helps, I updated my local fork to conform to (my reading of) the spec. dustismo@26baf6e

I can clean it up and issue a pull req if that implementation is correct.

[mreiferson]

hah, nice... excellent find...

Your last comment is the closest, the correct implementation will be the existing one in nsqd in master:

MPUB topic\n
[4-byte body size]
[4-byte num messages]
[4-byte message size][N-byte message]
[4-byte message size][N-byte message]
[4-byte message size][N-byte message]
...

When I introduced MPUB I probably implemented it for consistency with other commands with bodies (the body is always size prefixed) and forgot to update the docs.

I will update the docs and open a pull request against this issue.

[mreiferson]

let me know if that reads well for you and I'll merge... thanks again

[dustismo]

Great, thanks!