I think the short version is: in the past 5 years, simple wire-oriented serialisation formats have become much more common. At the time you had your pick of ASN (humongous) or Thrift (brand new).
Not particularly fair. You also had XDR (ubiquitous on Unix systems), IIOP, TLV, ICE... not to mention what ever protocol designer for the past 20 years has used: network byte order integers and ASCII/UTF8 strings.
Some people just like ASCII, human readable protocols. There's nothing wrong with that, but it's a little silly to suggest that the options for a packed binary encoding in 2007 were limited because Thrift and Protocol Buffers were too new.
I mentioned ASN.1 DER, but I honestly didn't think I should go into a history of XDR or other encodings. I guess I can't skip any history in a blog post....
I was responding to a comment, not your post. I don't think you really need to justify using an ASCII protocol (though, again, I think HTTP query arguments are a poor choice).
I don't believe a tl;dr is necessary for this short article.
I enjoyed reading through his thought process for designing a simple protocol which is:
* Easy to use (requiring little/no additional libraries)
* Easy to extend (simple keyword/value extensions)
* Immune to changes in technology
* (above all) easy to understand
Yet he himself says he considered and rejected a binary protocol for the reason I gave: "I considered using a binary format, but the immediate problem was having extendable fields.", going on to point out that he rejected Thrift because it was too new and ASN.DER because it was too big.
That said, I think he didn't want a binary format in any case -- his "doing it again today" remarks point to JSON.
Actually, the short version is: I wanted it easily debuggable by a network admin. (It's a point he made repeatedly). All the other arguments were moot.
How does a network admin debug a binary protocol for which no dissector has been implemented/merged into core for Wireshark, and no decoder has been written for tcpdump?
I can see both sides of the argument here, but basing a protocol on text just for the ease of eyeballing it on-the-wire seems like optimizing for the uncommon case.
Heck, almost any decent protocol should only have ciphertext on-the-wire anyway.
That's more or less like saying "well they can just write the decode". They're network administrators. If you use an ASCII protocol, they don't have to do anything.
I'm saying someone can write the decode and share it on their blog post or Github and your admin can start using it without having to recompile Wireshark. (I think, haven't actually tried it myself).
But even still, this only matters if:
A. The protocol is so new that Wireshark isn't shipping a parser,
B. the admin's stuff isn't working,
C. the admin can't get his stuff working by normal troubleshooting and must resort to observing the protocol,
D. the admin can't get his stuff working by observing the binary representation of the protocol, and
E. the admin actually can get his stuff working with a transliterated ASCII representation of the protocol.
Certainly I would probably find it easier to troubleshoot a text-based protocol too. I just think it's a relatively minor case in the grand scheme of things.
My point is that I imagine a network designer shouldn't focus on Wireshark or tcpdump integration over other non-functional requirements such as, well, network performance.
Network performance isn't as visible as the non-functional requirement of inspectability because it is amortised over potentially millions of machines, whereas inspectability is an immediately visible issue to the select few who "pop the hood" to fix an issue or simply to have a look.
For example: in terms of network capacity, I wonder how much HTTP headers cost all of us collectively. Probably a lot more than the cost of making a Wireshark plugin and having sysadmins install it as necessary.
Edit: put another way, I think designers should prioritise the needs of the people who pay the cost of network operation over the convenience of the operators.
There's a feedback loop here -- if it's too hard and thus very expensive to operate a system, then optimising for performance was a false win. But I don't think this is such a case, especially since as you pointed out elsewhere there are a number of very mature binary wire formats that were extant in 2007.
Not as absurd as you'd think. You don't want to debug the protocol itself, but you want to be able to easily read what messages were exchanged.
I get the rationale. But I think it's weak, and this entire post is lots of fluff around that core rationale. (I've been writing extensible binary protocols back in 1988 - and it never struck me as particularly difficult even back then.)
Some people just like ASCII, human readable protocols. There's nothing wrong with that, but it's a little silly to suggest that the options for a packed binary encoding in 2007 were limited because Thrift and Protocol Buffers were too new.