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From "Mutton, James" <>
Subject Re: [DISCUSS] Multiple Repositories for Erlang Apps and Dependencies
Date Fri, 17 Jan 2014 21:36:05 GMT
Excellent! Done, thanks.


On 1/17/14 11:44 AM, "Noah Slater" <> wrote:

>Done. Edit away! (Thanks!)
>On 17 January 2014 20:28, Mutton, James <> wrote:
>> JamesMutton
>> </JamesM>
>> On 1/17/14 11:09 AM, "Noah Slater" <> wrote:
>>>Good plan. What's your wiki username? I'll add you.
>>>On 17 January 2014 20:01, Mutton, James <> wrote:
>>>> Might I suggest that this sounds like good info to document on the
>>>> for committers getting started.  I'd add it but I'm not in the
>>>> :)
>>>> </JamesM>
>>>> On 1/17/14 4:00 AM, "Garren Smith" <> wrote:
>>>>>I'm claiming 2nd person added!
>>>>>On 17 Jan 2014, at 1:28 PM, Noah Slater <> wrote:
>>>>>> Psst. A little birdy tells me that if you ask nicely, the infra
>>>>>> will add you to the Apache GitHub org too, so you can show off your
>>>>>> Apache affiliation. I was the first person added. Because I may have
>>>>>> been the first to ask. ;)
>>>>>> On 17 January 2014 11:56, Noah Slater <>
>>>>>>> Awesome, thanks Paul.
>>>>>>> Note to all devs: if you want your contributions to CouchDB to
>>>>>>> on your GitHub profile, you have to star each of the repositories.
>>>>>>> (That's just how GitHub mechanics work for repo mirrors.)
>>>>>>> You can find them all here:
>>>>>>> On 17 January 2014 00:00, Paul Davis <>
>>>>>>>> New repos are up:
>>>>>>>> I'm gonna go through and initialize them with history from
>>>>>>>> one of the bigcouch and rcouch branches as appropriate.
>>>>>>>> On Thu, Jan 16, 2014 at 2:12 PM, Paul Davis
>>>>>>>><> wrote:
>>>>>>>>> Infrastructure ticket opened:
>>>>>>>>> On Thu, Jan 16, 2014 at 1:42 PM, Jan Lehnardt <>
>>>>>>>>>> On 16 Jan 2014, at 20:42 , Paul Davis
>>>>>>>>>>> It doesn't appear that this is objectionable
to anyone. Does
>>>>>>>>>>> have an objection to us having infra/me create
these repos to
>>>>>>>>>>> the bigcouch/rcouch merge work? This won't affect
master or
>>>>>>>>>>> until those merges finish.
>>>>>>>>>> no objections.
>>>>>>>>>> Jan
>>>>>>>>>> --
>>>>>>>>>>> On Tue, Jan 14, 2014 at 11:02 PM, Paul J Davis
>>>>>>>>>>> <> wrote:
>>>>>>>>>>>>> On Jan 14, 2014, at 8:37 PM, Benoit Chesneau
>>>>>>>>>>>>><> wrote:
>>>>>>>>>>>>> On Wed, Jan 15, 2014 at 12:22 AM, Paul
>>>>>>>>>>>>>> I've recently been having discussions
about how to handle
>>>>>>>>>>>>>> repository configuration for various
bits of CouchDB
>>>>>>>>>>>>>>post-merge. The
>>>>>>>>>>>>>> work that Benoit has been doing on
the rcouch merge branch
>>>>>>>>>>>>>> touched on this topic as well.
>>>>>>>>>>>>>> The background for those unfamiliar
is that the standard
>>>>>>>>>>>>>> procedure for Erlang is to have a
single Erlang application
>>>>>>>>>>>>>> repository and then rely on rebar
to fetch each dependency.
>>>>>>>>>>>>>> Traditionally in CouchDB land we've
always just included the
>>>>>>>>>>>>>>source to
>>>>>>>>>>>>>> all applications in a single monolithic
repository and
>>>>>>>>>>>>>> reimport changes from upstream dependencies.
>>>>>>>>>>>>>> Recently rcouch changed from the
monolithic repository to
>>>>>>>>>>>>>> repositories for some dependencies.
Originally the BigCouch
>>>>>>>>>>>>>>used an
>>>>>>>>>>>>>> even more federated scheme that had
each Erlang application
>>>>>>>>>>>>>> external repository (and the core
couch Erlang application
>>>>>>>>>>>>>>in the
>>>>>>>>>>>>>> root repository). When Bob Newson
and I did the initial
>>>>>>>>>>>>>>on the
>>>>>>>>>>>>>> BigCouch merge we pulled those external
dependencies into
>>>>>>>>>>>>>> repository reverting back to the
large monolithic approach.
>>>>>>>>>>>>>> After trying to deal with the merge
and contemplating how
>>>>>>>>>>>>>> Erlang release things might work
it's become fairly apparent
>>>>>>>>>>>>>>that the
>>>>>>>>>>>>>> monolithic approach is a bit constrictive.
For instance,
>>>>>>>>>>>>>> rebar's versioning abilities lets
you tag repositories to
>>>>>>>>>>>>>> versions rather than manually updating
versions in source
>>>>>>>>>>>>>> Another thing I've found on other
projects is that having
>>>>>>>>>>>>>> application in a separate repository
requires developers to
>>>>>>>>>>>>>>think a
>>>>>>>>>>>>>> bit more detailed about the public
internal interfaces used
>>>>>>>>>>>>>> out the system. We've done some work
to this extent already
>>>>>>>>>>>>>> separating source directories but
forcing commits to
>>>>>>>>>>>>>> repositories shoots up a big red
flag that maybe there's a
>>>>>>>>>>>>>> of coupling between two bits of code.
>>>>>>>>>>>>>> Other benefits of having the multiple
repository setup is
>>>>>>>>>>>>>> possible that this lends itself to
being integrated with the
>>>>>>>>>>>>>> plugin system. It'd be fairly trivial
to have a script that
>>>>>>>>>>>>>>went and
>>>>>>>>>>>>>> fetched plugins that aren't developed
at Apache (as a
>>>>>>>>>>>>>>./configure time
>>>>>>>>>>>>>> switch type of thing). Having a system
like this would also
>>>>>>>>>>>>>>allow us
>>>>>>>>>>>>>> to have groups focused on particular
bits of development not
>>>>>>>>>>>>>>have to
>>>>>>>>>>>>>> concern themselves with the unrelated
parts of the system.
>>>>>>>>>>>>>> Given all that, I'd like to propose
that we move to having a
>>>>>>>>>>>>>> repository for each application/dependency
that we use to
>>>>>>>>>>>>>> CouchDB. Each repository would be
hosted on ASF infra and
>>>>>>>>>>>>>>mirrored to
>>>>>>>>>>>>>> GitHub as expected. This means that
we could have the root
>>>>>>>>>>>>>> be a simple repo that contains packaging/release/build
>>>>>>>>>>>>>> would enable lots of the ideas offered
on configurable types
>>>>>>>>>>>>>> release generation. I've included
an initial list of
>>>>>>>>>>>>>>repositories at
>>>>>>>>>>>>>> the end of this email. Its basically
just the apps that have
>>>>>>>>>>>>>> split out in either rcouch or bigcouch
plus a few other bits
>>>>>>>>>>>>>> CouchDB master.
>>>>>>>>>>>>>> I would also point out that even
though our main repo would
>>>>>>>>>>>>>>need to
>>>>>>>>>>>>>> fetch other dependencies from the
internet to build the
>>>>>>>>>>>>>> we fully intend that our release
tarballs would *not* have
>>>>>>>>>>>>>> requirement. Ie, when we go to cut
a release part of the
>>>>>>>>>>>>>>process the
>>>>>>>>>>>>>> RM would run would be to pull all
of those dependencies
>>>>>>>>>>>>>> creating a tarball that would be
wholly self contained.
>>>>>>>>>>>>>> apache-couchdb-x.y.z.tar.gz release
file, there won't be a
>>>>>>>>>>>>>> to have access to the ASF git repos.
>>>>>>>>>>>>>> I'm not entirely sure how controversial
this is for anyone.
>>>>>>>>>>>>>> most part the reactions I remember
hearing were more
>>>>>>>>>>>>>> whether the infrastructure team would
allow us to use this
>>>>>>>>>>>>>> configuration. I looked yesterday
and asked and apparently
>>>>>>>>>>>>>> something we can request but as always
we'll want to verify
>>>>>>>>>>>>>>again if
>>>>>>>>>>>>>> we have consensus to move in this
>>>>>>>>>>>>>> Anyone have comments or flames? Right
now I'm just
>>>>>>>>>>>>>> feeling out what sort of (lack of?)
consensus there is on
>>>>>>>>>>>>>>such a
>>>>>>>>>>>>>> change. If there's general consensus
I'd think we'd do a
>>>>>>>>>>>>>>in a
>>>>>>>>>>>>>> couple weeks and if that passes then
start on down this road
>>>>>>>>>>>>>>for the
>>>>>>>>>>>>>> two merge projects and then it would
become part of master
>>>>>>>>>>>>>> land (as opposed to doing this to
master and then attempting
>>>>>>>>>>>>>> rcouch/bigcouch onto that somehow).
>>>>>>>>>>>>>> This is a quick pass at listing what
extra repositories I'd
>>>>>>>>>>>>>> created. Some of these applications
only exist in the
>>>>>>>>>>>>>> rcouch branches so that's where the
unfamiliar application
>>>>>>>>>>>>>>names are
>>>>>>>>>>>>>> from. I'd also point out that the
documentation and fauxton
>>>>>>>>>>>>>>things are
>>>>>>>>>>>>>> just on a whim in that we could decouple
that development
>>>>>>>>>>>>>> erlang development. I can see arguments
for an against
>>>>>>>>>>>>>>I'm much
>>>>>>>>>>>>>> less concerned on that aspect than
the Erlang parts that are
>>>>>>>>>>>>>> affected by rebar/Erlang conventions.
>>>>>>>>>>>>>>  chttpd
>>>>>>>>>>>>>>  config
>>>>>>>>>>>>>>  couch
>>>>>>>>>>>>>>  couch_collate
>>>>>>>>>>>>>>  couch_dbupdates
>>>>>>>>>>>>>>  couch_httpd
>>>>>>>>>>>>>>  couch_index
>>>>>>>>>>>>>>  couch_mrview
>>>>>>>>>>>>>>  couch_plugins
>>>>>>>>>>>>>>  couch_replicator
>>>>>>>>>>>>>>  documentation
>>>>>>>>>>>>>>  ddoc_cache
>>>>>>>>>>>>>>  ets_lru
>>>>>>>>>>>>>>  fabric
>>>>>>>>>>>>>>  fauxton
>>>>>>>>>>>>>>  ibrowse
>>>>>>>>>>>>>>  jiffy
>>>>>>>>>>>>>>  mem3
>>>>>>>>>>>>>>  mochiweb
>>>>>>>>>>>>>>  oauth
>>>>>>>>>>>>>>  rebar
>>>>>>>>>>>>>>  rexi
>>>>>>>>>>>>>>  snappy
>>>>>>>>>>>>>>  twig
>>>>>>>>>>>>> I also contemplated this and and I am
generally +1 on this.
>>>>>>>>>>>>> +1 to mirror them on the apache git if
possible.  I have a
>>>>>>>>>>>>>couple of
>>>>>>>>>>>>> comments though.
>>>>>>>>>>>>> Initially I also had everything separated
in its own source
>>>>>>>>>>>>>repository. 1
>>>>>>>>>>>>> year ago I merged back as one core repo
the couchdb erlang
>>>>>>>>>>>>>applications and
>>>>>>>>>>>>> put all the dependencies in the refuge
repository or in the
>>>>>>>>>>>>>refuge CDN for
>>>>>>>>>>>>> the spidermonkey and ICU sources.
>>>>>>>>>>>>> I merged back as one core repo the couchdb
>>>>>>>>>>>>>because they
>>>>>>>>>>>>> were a little too much dependant. Especially
>>>>>>>>>>>>>couch_index and
>>>>>>>>>>>>> couch_mrview. These applications are
not yet enough by
>>>>>>>>>>>>> Imo if we split everything in  their
own apps, then we should
>>>>>>>>>>>>>make sure
>>>>>>>>>>>>> that couch_httpd can be used without
couch_index and
>>>>>>>>>>>>>couch_mrview (which
>>>>>>>>>>>>> means that "all_docs" is available in
couch_httpd). Also we
>>>>>>>>>>>>>should be able
>>>>>>>>>>>>> to just launch couch without any of the
above. And probably
>>>>>>>>>>>>>without the
>>>>>>>>>>>>> need of an ini. The couch_query_server
module thing is an
>>>>>>>>>>>>>interesting case.
>>>>>>>>>>>>> bigcouch is also introducing `ddoc_cache`
which I am not sure
>>>>>>>>>>>>>why it is
>>>>>>>>>>>>> provided as a standalone app. Does it
means it can be
>>>>>>>>>>>>>by another
>>>>>>>>>>>>> application eventually? Why not having
it simply in the
>>>>>>>>>>>>> Does it needs to be updated separately?
>>>>>>>>>>>>> Also  all our base applications should
also be named spaced
>>>>>>>>>>>>>correctly so
>>>>>>>>>>>>> they will be strictly identified as erlang
modules:  "config"
>>>>>>>>>>>>> generic, "ddoc_cache" too. Others are
probably OK.
>>>>>>>>>>>>> There are probably other things that
we could provide as
>>>>>>>>>>>>> - couch_daemon,
>>>>>>>>>>>>> - couch_js
>>>>>>>>>>>>> - couch_external
>>>>>>>>>>>>> - couch_stats
>>>>>>>>>>>>> - couch_compaction_daemon
>>>>>>>>>>>>> - couch_httpd_proxy
>>>>>>>>>>>>> Anyway again i'm +1 for this move, I
really think it's a good
>>>>>>>>>>>>> - benoit
>>>>>>>>>>>> I agree on most of this. Roughly I see three
general points.
>>>>>>>>>>>> First, deciding on whether some things are
external deps is
>>>>>>>>>>>>definitely up for discussion. Whether couch_mrview
is a
>>>>>>>>>>>>app/repo is not necessarily clear cut. Personally
I think I
>>>>>>>>>>>>engineered couch_index which blurs the lines
a bit. If I could
>>>>>>>>>>>>wave a wand I'd have just couch_mrview and
it'd be separate.
>>>>>>>>>>>>importantly I think the separate repos makes
these things more
>>>>>>>>>>>>apparent. The fact were discussing this sort
of architecture
>>>>>>>>>>>>is suggestive that it's forcing us to think
a bit harder.
>>>>>>>>>>>> Second is the aspect of composability. For
instance the mrview
>>>>>>>>>>>>thing to me is obviously a different repo
precisely so a user
>>>>>>>>>>>>could import couch (_core?) directly without
requiring the
>>>>>>>>>>>>monkey dependency. The monolithic repo doesn't
allow this
>>>>>>>>>>>>some very non-standard tooling.
>>>>>>>>>>>> Thirdly, app naming is always a contention.
The config name
>>>>>>>>>>>>actually a hot code upgrade concern. We couldn't
>>>>>>>>>>>>couch_config directly at the time. And Adam
was also hopeful we
>>>>>>>>>>>>could the it into a useful non-specific config
>>>>>>>>>>>> Fourthly, and related to secondly, we'll
also want to look at
>>>>>>>>>>>>splitting other apps out as necessary. The
ones you listed I
>>>>>>>>>>>>aren't controversial it's just that no one
has done it yet. My
>>>>>>>>>>>>list was purely what existed so far without
attempting to carve
>>>>>>>>>>>>things up more. I definitely agree we should
carve more in just
>>>>>>>>>>>>wanted to cover consensus that carving is
the right direction.
>>>>>>>>>>>> Fifthly, I'm done typing on my phone. I'll
fill in more
>>>>>>> --
>>>>>>> Noah Slater
>>>>>> --
>>>>>> Noah Slater
>>>Noah Slater
>Noah Slater

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