What important tools or browsers still need text/plain for our json responses 
that justify the mismatch?


On 19 Jul 2014, at 11:30, Jan Lehnardt <[email protected]> wrote:

> 
> On 19 Jul 2014, at 12:27 , Robert Samuel Newson <[email protected]> wrote:
> 
>> I agree with you on the category split and, obviously, that we can make a 
>> 3.0 whenever we like, since it only indicates compatibility breaks.
>> 
>> MVCC for _security will be great since it will enable us to heal _security 
>> writes during partitions with the same logic we use for documents. Cloudant 
>> worked around (hacked around) that problem for a long time but we’ve finally 
>> done the work to add MVCC for reals, so it’ll be nice to bring that 
>> enhancement to CouchDB officially.
> 
> Yeah, I don’t see a reason not to get this in for 2.0.
> 
> 
>> I don’t think defaulting to conflicts=true is quite the right change. I was 
>> thinking that conflicted document would return a 300 Multiple Choices 
>> instead of a 200 OK (the response body format TBD but imagine a JSON array 
>> of each conflicting leaf revision). I agree that a change like that will 
>> break every client, but that would be the intention. A CouchDB 3.0 would be 
>> much more forthcoming about its fundamental architecture and would largely 
>> eschew the attempts to present an arbitrary "winning" revision.
> 
> Right, this was just meant as a possible compromise to get a more 
> first-class-conflict API without making this 3-rd category change. Happy to 
> abandon it :)
> 
> 
>> One further thought occurs, could we totally ditch the code that returns 
>> "text/plain" content-type? All that "are you a browser?" logic? It made 
>> sense at the time, but I feel it confuses more than it helps today.
> 
> I use that all the time :)
> 
> Best
> Jan
> -- 
> 
> 
> 
>> 
>> B.
>> 
>> 
>> On 19 Jul 2014, at 10:50, Jan Lehnardt <[email protected]> wrote:
>> 
>>> 
>>> On 19 Jul 2014, at 10:38 , Robert Samuel Newson <[email protected]> wrote:
>>> 
>>>> 
>>>> I think this is backward. We are not proposing API changes "just because" 
>>>> BigCouch happens to make them.
>>>> 
>>>> Given that we have to bump the major version number, we are afforded an 
>>>> opportunity to improve our API in significant ways for the first time 
>>>> since 1.0. We all know there are warts to be fixed. The question is what 
>>>> to fix with 2.0, seeing as we’re making one.
>>> 
>>> That is what I meant to express, with the caveat that we should be
>>> careful, taking a conservative stance, so we can meet in the middle.
>>> 
>>> 
>>>> I would also hate to see low adoption of CouchDB 2.0 if we change too 
>>>> much, because I’ve spent quite a bit of time trying to make it happen.
>>>> 
>>>> Is there nothing, besides what comes with the BigCouch merge, that we 
>>>> wouldn’t want to change for 2.0? At least the ability to add metadata 
>>>> without breaking 2.0 compliant clients and libraries, I hope?
>>> 
>>> 
>>> Most apps should continue to work on CouchDB 2.0.
>>> 
>>> Specifically, the regular document CRUD cycle should work as-is.
>>> Especially moving things around in the JSON usually goes further
>>> than the HTTP/Couch layer of most apps, as it is usually passed
>>> down into the rest of the app, while HTTP specifics are kept on
>>> the outside.
>>> 
>>> In that scenario, adding properties should be easier to do than
>>> removing them (e.g. _conflicts could be standard, but renaming
>>> _rev to _mvcc would break things more significantly), although
>>> Bob mentioned the replicator compatibility as a major concern,
>>> so we need to make sure this is doable.
>>> 
>>> My main point here is to start a discussion about how we would
>>> go about evolving this down the road and my suggestion was the
>>> separate API endpoint that we can mess with at will and gradually
>>> introduce until we switch at a later time when we feel confident
>>> that people have migrated, or a solid compatibility API is available.
>>> 
>>> I see us having three discussions:
>>> 
>>> 1. What do we want to fix/break for 2.0?
>>> 2. How do we introduce fixes/breaks that we aren’t comfortable doing for 
>>> 2.0?
>>> 3. What do we want to fix/break for later versions?
>>> 
>>> 
>>> From this thread, I’d handwavingly suggest these fall into category 1:
>>> (as per the “most apps should just continue to work”-mantra):
>>> 
>>> - timeout and heartbeat params for /_db_updates works in different way
>>> then the same parameters for changes feed;
>>> - we need to find the way to pass open_revs in POST body instead of
>>> tweaking max URL param;
>>> - we have /db/_revs_diff and /db/_revs_missing endpoints which are
>>> doing the same job. Well, the latter is only used for pre-1.1 CouchDB
>>> replicator.
>>> - /db/doc accepts conflicts, deleted_conflicts and revs params. In the
>>> same time we provides meta one which includes each of specified.
>>> - make eventsource feed to follow the specification format more better
>>> then it does now
>>> - MVCC for /db/_security and allow atomic changes for admins/members only
>>> - a variant of “Changing the default respones for conflicts to include all
>>> versions (or no version).” where ?conflicts=BOOL defaults to true, so we
>>> get an additional _conflicts: [] member on regular GETs (if there are
>>> conflicts), but not the conflicting versions themselves (see above note
>>> about additional doc members)
>>> - Fix the list API (inside couchjs) so that its a pure callback like
>>> everything else.
>>> - 'JSONP responses should be sent with a "application/javascript"'
>>> 
>>> 
>>> These fall into category 3:
>>> 
>>> - Change _rev to _mvcc or other.
>>> - Move document metadata elsewhere (sub-object, headers, whatever)
>>> - Changing the default respones for conflicts to include all versions
>>> (or no version).
>>> - more RESTy API (move /_all_docs to /, db info to _info etc), 
>>> self-defining REST API
>>> - don’t pollute top level namespace (e.g. /database moves to /db/database)
>>> 
>>> This isn’t exhaustive, and we don’t yet know the answers to some of them.
>>> 
>>> As a repeat: with our new understanding of SemVer, we are free to ship 
>>> CouchDB
>>> 3.0 a month after 2.0, if we really want to. We are not beholden to 
>>> marketing
>>> version numbers after 2.0 (strictly, we aren’t for 2.0 either, but it is
>>> rather convenient :).
>>> 
>>> * * *
>>> 
>>> The view server protocol change suggested by Samuel is IMHO an internal
>>> change that should not break BC unless people rely on implementation 
>>> details.
>>> 
>>> 
>>> * * *
>>> 
>>> Most apps should continue to work on CouchDB 2.0.
>>> 
>>> Jan
>>> -- 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>> 
>>>> Adding a new top-level _-prefixed field in couchdb causes the replicator 
>>>> to crash hard, this is unacceptable brittle imo.
>>> 
>>>> 
>>>> B.
>>>> 
>>>> On 18 Jul 2014, at 21:15, Jan Lehnardt <[email protected]> wrote:
>>>> 
>>>>> I’m major -1 on substantial API changes *just* because we are having some
>>>>> by necessity of getting BigCouch in.
>>>>> 
>>>>> The minor improvements mentioned previously in this thread sound 
>>>>> reasonable,
>>>>> but changing the main JSON format seems like a rather bad idea as it will
>>>>> just break all clients. While the scenario is a little different, I’d 
>>>>> like to
>>>>> avoid a Python 3 kind of situation (I think CouchDB 2.0 has more to offer 
>>>>> over
>>>>> 1.0 than Python 3 had over 2, but still, there is no need to make this 
>>>>> harder
>>>>> for our users, if we don’t have to).
>>>>> 
>>>>> That said, we likely want to evolve the API at some point and I think we 
>>>>> should
>>>>> nail down a strategy on *how* to do that, before getting into the details 
>>>>> of
>>>>> what should change.
>>>>> 
>>>>> One option, and I haven’t thought this through, would be to use separate 
>>>>> ports
>>>>> for a new API endpoint that we can evolve while keeping the current one. 
>>>>> And
>>>>> we can do the deprecation and switch dance some time in the future. We 
>>>>> could
>>>>> even try multiple competing APIs, even non HTTP APIs (all things, I’d 
>>>>> love to
>>>>> see, so we can learn from them). Of course there is a certain overhead in
>>>>> maintaining this all, and I don’t know if there are any roadblocks in the 
>>>>> way
>>>>> BigCouch works today for implementing this.
>>>>> 
>>>>> Best
>>>>> Jan
>>>>> --
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> 
>>>>> On 17 Jul 2014, at 21:03 , Russell Branca <[email protected]> wrote:
>>>>> 
>>>>>> I would also love to see _rev renamed, and I think it's a good
>>>>>> opportunity to flip around all the meta info as well. I'm still
>>>>>> partial to moving the relevant metadata into the headers, and no
>>>>>> longer including any _* fields in the doc, but I know there are
>>>>>> proponents on both sides of the coin there. The most recent proposal I
>>>>>> could find is to move all the metadata into a '_' field [1]. In 2.0 I
>>>>>> would like to see us move all metadata into headers or into the '_'
>>>>>> field, and rename 'rev'. There's a lot of code overlap for the two so
>>>>>> it seems like an opportune time to do it.
>>>>>> 
>>>>>> I wonder if it's reasonable to make the use of a '_' field or exposed
>>>>>> through headers configurable. I'm not sure it's a great idea to do so,
>>>>>> but it's at least worth thinking about.
>>>>>> 
>>>>>> Exposing conflicts by default is another thing I'm keen on. The
>>>>>> question is how to make it "fail" loudly so that client libraries
>>>>>> don't just think it's the document body. An aggressive approach send a
>>>>>> list of conflict revs rather than a doc object which will break all
>>>>>> existing parsers and require users to deal with. Then if you want a
>>>>>> particular rev, you'll need to specify it in the request.
>>>>>> 
>>>>>> We could also cleanup the API endpoints to make them more RESTful. IMO
>>>>>> things like _all_dbs and _all_docs should be the top level endpoints
>>>>>> and the current info endpoints moved to _info or some such.
>>>>>> 
>>>>>> Along the lines of API cleanup is the capabilities engine. I think
>>>>>> this would be a great thing to land, and if done properly could be a
>>>>>> self defining REST endpoint showing all the things the server is
>>>>>> capable of and how to reach them.
>>>>>> 
>>>>>> 
>>>>>> 
>>>>>> -Russell
>>>>>> 
>>>>>> 
>>>>>> [1] 
>>>>>> http://mail-archives.apache.org/mod_mbox/couchdb-dev/201312.mbox/%[email protected]%3E
>>>>>> 
>>>>>> On Thu, Jul 17, 2014 at 2:14 AM, Robert Samuel Newson
>>>>>> <[email protected]> wrote:
>>>>>>> Great point, +1 to just making that change on master right now.
>>>>>>> 
>>>>>>> B.
>>>>>>> 
>>>>>>> On 16 Jul 2014, at 22:35, Robert Kowalski <[email protected]> wrote:
>>>>>>> 
>>>>>>>> I would like to see 'JSONP responses should be sent with a
>>>>>>>> "application/javascript"' (https://github.com/apache/couchdb/pull/236)
>>>>>>>> beside the two merges in the 2.0 release - it is a small, but breaking
>>>>>>>> change and the original issue is flying around in Jira for years.
>>>>>>>> 
>>>>>>>> Best,
>>>>>>>> Robert
>>>>>>>> 
>>>>>>>> 
>>>>>>>> 2014-07-13 22:17 GMT+02:00 Robert Samuel Newson <[email protected]>:
>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> Since we follow semantic versioning, the only meaning behind naming 
>>>>>>>>> our
>>>>>>>>> next release 2.0 and not 1.7 is that it contains backwards 
>>>>>>>>> incompatible
>>>>>>>>> changes.
>>>>>>>>> 
>>>>>>>>> It’s for the CouchDB community as a whole to determine what is and 
>>>>>>>>> isn’t
>>>>>>>>> in a release. Certainly merging in bigcouch and rcouch are a huge 
>>>>>>>>> part of
>>>>>>>>> the 2.0 release, but they aren’t necessarily the only things. If they
>>>>>>>>> hadn’t changed the API in incompatible ways, they wouldn’t cause a 
>>>>>>>>> major
>>>>>>>>> version bump.
>>>>>>>>> 
>>>>>>>>> With that said then, I’m interested in hearing what else, besides the 
>>>>>>>>> two
>>>>>>>>> merges, we feel we want to take on in our first major revision bump in
>>>>>>>>> approximately forever? At minimum, I would like to see a change that 
>>>>>>>>> allows
>>>>>>>>> us to use versions of spidermonkey released after 1.8.5, whatever that
>>>>>>>>> change might be.
>>>>>>>>> 
>>>>>>>>> B.
>>>>>>>>> 
>>>>>>>>> On 13 Jul 2014, at 20:31, Joan Touzet <[email protected]> wrote:
>>>>>>>>> 
>>>>>>>>>> Improving the view server protocol is a great idea, but it is 
>>>>>>>>>> appropriate
>>>>>>>>>> for a 2.0 timeframe? I would think it would make more sense in a 3.0
>>>>>>>>>> timeframe, given 2.0 is all about merging forks, not writing new 
>>>>>>>>>> features
>>>>>>>>>> entirely from scratch.
>>>>>>>>>> 
>>>>>>>>>> -Joan
>>>>>>>>>> 
>>>>>>>>>> ----- Original Message -----
>>>>>>>>>> From: "Robert Samuel Newson" <[email protected]>
>>>>>>>>>> To: [email protected]
>>>>>>>>>> Sent: Sunday, July 13, 2014 8:52:40 AM
>>>>>>>>>> Subject: Re: CouchDB 2.0: breaking the backward compatibility
>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>>>> Adding mvcc for _security is a great idea (happily, Cloudant have 
>>>>>>>>>> done
>>>>>>>>> so very recently, so I will be pulling that work over soon).
>>>>>>>>>> 
>>>>>>>>>> A better view server protocol is also a great idea.
>>>>>>>>>> 
>>>>>>>>>> 
>>>>>>>>>> On 13 Jul 2014, at 13:13, Samuel Williams <
>>>>>>>>> [email protected]> wrote:
>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>>>> On 13/07/14 23:47, Alexander Shorin wrote:
>>>>>>>>>>>> Our view server is compiles functions on each view index update
>>>>>>>>>>>> instead of reusing inner cache. This is because of out-dated 
>>>>>>>>>>>> protocol:
>>>>>>>>>>>> others design function are works differently from views. While it's
>>>>>>>>>>>> good to change and improve query server protocol completely, this 
>>>>>>>>>>>> task
>>>>>>>>>>>> requires more time to be done. We should have a least plan B to do
>>>>>>>>>>>> small steps in good direction.
>>>>>>>>>>> As already suggested, here is my proposal for 2.0 view/query server:
>>>>>>>>>>> 
>>>>>>>>>>> 
>>>>>>>>> https://docs.google.com/document/d/1JtfvCpNB9pRQyLhS5KkkEdJ-ghSCv89xnw5HDMTCsp8/edit
>>>>>>>>>>> 
>>>>>>>>>>> I welcome people to suggest improvements/changes/ideas.
>>>>>>>>>>> 
>>>>>>>>>>> Kind regards,
>>>>>>>>>>> Samuel
>>>>>>>>>> 
>>>>>>>>> 
>>>>>>>>> 
>>>>>>> 
>>>>> 
>>>> 
>>> 
>> 
> 

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