Brian, I'm curious whether most python HTTP libraries support using custom HTTP request headers.
We'll land benh's patches to send 202 responses in 0.19.0: https://reviews.apache.org/r/20276/ https://reviews.apache.org/r/20277/ Once these get committed, you should be able to get something working nicely. This will allow libraries like "pesos" to use a custom header "Libprocess-From" to receive 202 responses for messages. We'd also like to get some more foundation laid for the lower-level API, I'll let benh comment on what else is needed here: https://reviews.apache.org/r/20309/ On Sun, Apr 27, 2014 at 9:23 PM, Vetoshkin Nikita < nikita.vetosh...@gmail.com> wrote: > That's great news indeed! > Maybe there should be a place on mesos site mentioning such efforts? > > > On Mon, Apr 28, 2014 at 5:24 AM, Brian Wickman <wick...@gmail.com> wrote: > > > To my knowledge there is no Zookeeper Group implementation for Go yet. > > There do however appear to be Go zookeeper > > bindings<https://github.com/samuel/go-zookeeper>. > > From my day of spelunking through code, it seems that probably the most > > challenging thing will be getting a ZookeeperMasterDetector > implementation > > working correctly to enable Scheduler "high availability" mode for these > > other languages. > > > > Java/Python/C++ have the benefit of preexisting Group implementations > > (java< > > > https://github.com/twitter/commons/blob/master/src/java/com/twitter/common/zookeeper/Group.java > > > > > , python< > > > https://github.com/twitter/commons/blob/master/src/python/twitter/common/zookeeper/group/kazoo_group.py > > > > > , c++< > > > https://git-wip-us.apache.org/repos/asf?p=mesos.git;a=blob;f=src/zookeeper/group.cpp;h=70972980dd25618c76eb36e0a31d060c096e36dc;hb=HEAD > > >) > > which are the foundation for ZK master detection. An intermediate option > > could be to pull the ZookeeperMasterDetectorProcess out into a standalone > > binary and have the native implementation talk to it as a sort of proxy > to > > figure out who the leading master is. But that's not nearly as > satisfying > > as a pure language implementation. > > > > ~brian > > > > > > On Sun, Apr 27, 2014 at 3:22 PM, Vladimir Vivien > > <vladimir.viv...@gmail.com>wrote: > > > > > It must be the right time for this. I started the same effort for Go. > > > I am following Kevin's example and Ben's well-documented email (in this > > > thread). > > > Very early but should have some proof-of-concept working soon. > > > > > > https://github.com/vladimirvivien/ionos > > > > > > > > > On Sun, Apr 27, 2014 at 6:07 PM, Tom Arnfeld <t...@duedil.com> wrote: > > > > > >> (Sorry to jump into this thread) > > >> > > >> I have to say, this is very exciting! It only became apparent to me > how > > >> painful it is having to compile the mesos egg into a Python framework > > the > > >> past week > > >> while writing one, especially when running the framework on a > different > > >> architecture to the one running the executor! > > >> > > >> Looking forward to being able to use this. :-) > > >> > > >> It’d be awesome if the API was near identical, so one could switch > > >> between `mesos` and `pesos` easily… > > >> > > >> Tom. > > >> > > >> On 27 Apr 2014, at 22:42, Brian Wickman <wick...@gmail.com> wrote: > > >> > > >> > And I've started a skeleton implementation of the Mesos framework > API > > at > > >> > https://github.com/wickman/pesos > > >> > > > >> > While I vendored the translated protobuf, it would be great to > tackle > > >> > https://issues.apache.org/jira/browse/MESOS-857 at some point. > > >> > > > >> > > > >> > On Sun, Apr 27, 2014 at 12:50 PM, Brian Wickman <wick...@gmail.com> > > >> wrote: > > >> > > > >> >> I've implemented a pure python version of the basic > > >> >> Process/ProtobufProcess mechanics and wire protocol. I haven't > gone > > >> so far > > >> >> as Kevin and tried to register a framework or maybe talk to a > > >> replicated > > >> >> log, but it shouldn't be much more work: > > >> >> > > >> >> https://github.com/wickman/compactor > > >> >> > > >> >> Zero documentation but you can read the tests for a general idea of > > >> what's > > >> >> going on. > > >> >> > > >> >> cheers, > > >> >> brian > > >> >> > > >> >> > > >> >> > > >> >> On Sun, Apr 13, 2014 at 10:28 PM, Kevin Sweeney < > > >> kevin.t.swee...@gmail.com > > >> >>> wrote: > > >> >> > > >> >>> I've got the start of a JVM verson on github - it can currently > > >> register > > >> >>> a framework and parse the response. Client-side I still need to > > >> figure out > > >> >>> how to properly configure Keep-Alive. Servlet can dispatch > messages > > to > > >> >>> message handlers in a type-safe way and returns a 202 for messages > > >> it's > > >> >>> going to handle. Code's a mess currently. > > >> >>> > > >> >>> https://github.com/kevints/mesos-framework-api > > >> >>> > > >> >>> > > >> >>> On Fri, Apr 11, 2014 at 7:12 PM, Benjamin Hindman < > > >> b...@eecs.berkeley.edu > > >> >>>> wrote: > > >> >>> > > >> >>>> First, my apologies for getting to this party so late. It's great > > to > > >> see > > >> >>>> people interested in helping create native-language Mesos > > libraries. > > >> >>>> > > >> >>>> Vladimir: my presentation was definitely referring to the the > > >> low-level > > >> >>>> protocol between master, framework (scheduler), slave, and > > >> executors. I'll > > >> >>>> do my best here to clarify how the current protocol works and > what > > >> we need > > >> >>>> to do to get it to the point where we can write native-language > > >> libraries. > > >> >>>> (Eventually it would be great to move some of this into > > >> documentation as > > >> >>>> necessary.) > > >> >>>> > > >> >>>> As Nikita pointed out, the protocol is currently "HTTP-like". As > my > > >> >>>> presentation describes, think actors and one-way message passing > > when > > >> >>>> considering how the protocol works. > > >> >>>> > > >> >>>> To send a message an actor POSTs an HTTP request where the actor > > >> that is > > >> >>>> supposed to receive the message is the first component of the > > >> request path > > >> >>>> and the name of the message is the remaining part of the path. To > > >> >>>> distinguish one of these "messages" from a normal HTTP request we > > >> look to > > >> >>>> see if the 'User-Agent' is 'libprocess/...'. For example: > > >> >>>> > > >> >>>> POST /master/mesos.internal.RegisterFrameworkMessage HTTP/1.1 > > >> >>>> User-Agent: libprocess/scheduler(1)@10.0.1.7:53523 > > >> >>>> > > >> >>>> ... represents a message with the name > > >> >>>> 'mesos.internal.RegisterFrameworkMessage' destined for the actor > > >> 'master' > > >> >>>> coming from the actor 'scheduler(1)' at 10.0.1.7:53523. If the > > >> 'master' > > >> >>>> actor were to send a message back it would look something like > > this: > > >> >>>> > > >> >>>> POST /scheduler(1)/mesos.internal.FrameworkRegisteredMessage > > HTTP/1.1 > > >> >>>> User-Agent: libprocess/master@10.0.1.7:5050 > > >> >>>> > > >> >>>> So, one-way message passing via HTTP POST. > > >> >>>> > > >> >>>> The message data is captured as the body of the HTTP request > (which > > >> can > > >> >>>> be specified using _either_ Content-Length or a > Transfer-Encoding, > > >> and as > > >> >>>> Nikita points out we use chunked transfer encoding internally). > The > > >> data is > > >> >>>> arbitrary and the actor ultimately decides how it wants to > "parse" > > >> it. In > > >> >>>> Mesos, 99% of our messages use serialized protobufs, but we also > > >> send a few > > >> >>>> messages with just arbitrary data. All this really means is that > > >> knowing > > >> >>>> the actor and message name is not enough, you also need to know > > what > > >> the > > >> >>>> body type is supposed to be for that message. In the future we'll > > >> probably > > >> >>>> enable messages with either JSON or serialized protobuf[1] ... > for > > >> now, > > >> >>>> just serialized protobuf. > > >> >>>> > > >> >>>> Okay, so where does this break down when trying to do this > > >> >>>> language-natively? I've had some of this in the works and this > > >> conversation > > >> >>>> has motivated me to publish some reviews addressing the issues: > > >> >>>> > > >> >>>> (1) We'll need to return a response if one plans to use a native > > HTTP > > >> >>>> library since it'll expect request/response. > > >> >>>> https://reviews.apache.org/r/20276 introduces responding with a > > '202 > > >> >>>> Accepted' for these messages (from the HTTP specification, a '202 > > >> >>>> Accepted': "The request has been accepted for processing, but the > > >> >>>> processing has not been completed. The request might or might not > > >> >>>> eventually be acted upon, as it might be disallowed when > processing > > >> >>>> actually takes place. There is no facility for re-sending a > status > > >> code > > >> >>>> from an asynchronous operation such as this."). > > >> >>>> > > >> >>>> (2) Most HTTP libraries will set their 'User-Agent' themselves, > so > > >> >>>> https://reviews.apache.org/r/20277 introduces a > 'libprocess-from' > > >> >>>> header that works similar to User-Agent. There is still some > > cleanup > > >> I'd > > >> >>>> love to do around stringification of PIDs (the underlying type > > Mesos > > >> uses > > >> >>>> for remote actors, inspired by Erlang). Until then, the > > >> 'libprocess-from' > > >> >>>> string is unfortunately esoteric (see the test). > > >> >>>> > > >> >>>> The combination of these two patches should make sending and > > >> receiving > > >> >>>> messages straightforward. However, we still plan to expose the > > >> low-level > > >> >>>> Event and Call protobuf messages and that will be the preferred > > >> approach > > >> >>>> for building a native-language library. Follow along at > > >> >>>> https://issues.apache.org/jira/browse/MESOS-1127 for more > details. > > >> (To > > >> >>>> be clear, you'd still be able to implement native-language > > libraries > > >> with > > >> >>>> the patches above but we'll be deprecating the protobufs you'd be > > >> using in > > >> >>>> favor of Event and Call protobufs instead. If you're eager to get > > >> that > > >> >>>> going before Event and Call are committed I'm happy to discuss > the > > >> existing > > >> >>>> protobufs in more detail.) > > >> >>>> > > >> >>>> I hope this helps. > > >> >>>> > > >> >>>> Ben. > > >> >>>> > > >> >>>> > > >> >>>> On Fri, Apr 11, 2014 at 4:54 AM, Vladimir Vivien < > > >> >>>> vladimir.viv...@gmail.com> wrote: > > >> >>>> > > >> >>>>> Nikita > > >> >>>>> Thanks for the JIRA. > > >> >>>>> > > >> >>>>> > > >> >>>>> On Wed, Apr 9, 2014 at 2:16 PM, Vetoshkin Nikita < > > >> >>>>> nikita.vetosh...@gmail.com > > >> >>>>>> wrote: > > >> >>>>> > > >> >>>>>> BTW, there is also somehow related ticket > > >> >>>>>> https://issues.apache.org/jira/browse/MESOS-930 > > >> >>>>>> > > >> >>>>>> > > >> >>>>>> On Wed, Apr 9, 2014 at 9:54 PM, Benjamin Mahler > > >> >>>>>> <benjamin.mah...@gmail.com>wrote: > > >> >>>>>> > > >> >>>>>>>> > > >> >>>>>>>> I thought the low-level api being referred in the > > >> >>>>>>>> video had to do with communication between master and > > >> >>>>>> framework|executor > > >> >>>>>>>> for scheduling. But, it's really administrative. I thought > > that > > >> >>>>> would > > >> >>>>>>>> have been an opportunity for a Go binding that did not > require > > >> >>>>> the C++ > > >> >>>>>>>> libraries. > > >> >>>>>>>> > > >> >>>>>>> > > >> >>>>>>> Vladimir, the low-level API referred to in the talk is exactly > > >> what > > >> >>>>>> you're > > >> >>>>>>> interpreting, it is for communication between master and > > >> scheduler, > > >> >>>>> and > > >> >>>>>>> slave and executor. You could definitely build pure go > bindings > > as > > >> >>>>> you > > >> >>>>>>> described, just not with JSON. > > >> >>>>>>> > > >> >>>>>>> Forget I mentioned anything about the administrative endpoints > > and > > >> >>>>> JSON, > > >> >>>>>> as > > >> >>>>>>> I see that's leading to confusion. ;) > > >> >>>>>>> > > >> >>>>>>> On Wed, Apr 9, 2014 at 3:39 AM, Vladimir Vivien > > >> >>>>>>> <vladimir.viv...@gmail.com>wrote: > > >> >>>>>>> > > >> >>>>>>>> Ben, > > >> >>>>>>>> Thank you for clarifying. I thought the low-level api being > > >> >>>>> referred in > > >> >>>>>>> the > > >> >>>>>>>> video had to do with communication between master and > > >> >>>>>> framework|executor > > >> >>>>>>>> for scheduling. But, it's really administrative. I thought > > that > > >> >>>>> would > > >> >>>>>>>> have been an opportunity for a Go binding that did not > require > > >> >>>>> the C++ > > >> >>>>>>>> libraries. > > >> >>>>>>>> > > >> >>>>>>>> Thanks anyway. > > >> >>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> On Tue, Apr 8, 2014 at 4:52 PM, Benjamin Mahler > > >> >>>>>>>> <benjamin.mah...@gmail.com>wrote: > > >> >>>>>>>> > > >> >>>>>>>>> Sorry, I was not referring to implementing a scheduler via > > JSON > > >> >>>>>> instead > > >> >>>>>>>> of > > >> >>>>>>>>> protobuf, in theory that would be possible but there has > been > > no > > >> >>>>>>> planning > > >> >>>>>>>>> in this area. Sorry for the confusion. > > >> >>>>>>>>> > > >> >>>>>>>>> I was referring to administrative endpoints. For example, > > >> >>>>> kicking a > > >> >>>>>>>>> framework out or telling the master a slave is needs to be > > >> >>>>> repaired. > > >> >>>>>>>> These > > >> >>>>>>>>> endpoints may rely on the ability to convert JSON to > internal > > >> >>>>>>> protobufs. > > >> >>>>>>>>> > > >> >>>>>>>>> Can you clarify what you're looking to do? Are you looking > to > > >> >>>>>> implement > > >> >>>>>>>> an > > >> >>>>>>>>> API in Go that communicates with JSON instead of serialized > > >> >>>>> protobuf? > > >> >>>>>>>>> > > >> >>>>>>>>> On Tue, Apr 8, 2014 at 1:19 PM, Vladimir Vivien > > >> >>>>>>>>> <vladimir.viv...@gmail.com>wrote: > > >> >>>>>>>>> > > >> >>>>>>>>>> Ben, > > >> >>>>>>>>>> That is exactly what I am asking. > > >> >>>>>>>>>> Is that something coming up soon, is there a JIRA I can > look > > >> >>>>> at? > > >> >>>>>>>>>> I wanna get early start on a native json Go api or even > help > > >> >>>>> out if > > >> >>>>>>>>>> possible. > > >> >>>>>>>>>> > > >> >>>>>>>>>> > > >> >>>>>>>>>> On Tue, Apr 8, 2014 at 3:25 PM, Benjamin Mahler > > >> >>>>>>>>>> <benjamin.mah...@gmail.com>wrote: > > >> >>>>>>>>>> > > >> >>>>>>>>>>> +vinod, benh > > >> >>>>>>>>>>> > > >> >>>>>>>>>>> Hey Vladimir, there will be some authenticated REST > > >> >>>>> endpoints at > > >> >>>>>>> some > > >> >>>>>>>>>>> point, there is some work in this area underway. > > >> >>>>>>>>>>> > > >> >>>>>>>>>>> We have the ability to encode protobuf messages as JSON, > so > > >> >>>>> the > > >> >>>>>>> plan > > >> >>>>>>>>> was > > >> >>>>>>>>>> to > > >> >>>>>>>>>>> have any REST endpoints directly use JSON to send us > > >> >>>>> protobuf > > >> >>>>>>>> messages. > > >> >>>>>>>>>> I'm > > >> >>>>>>>>>>> not sure if this is what you're asking though? > > >> >>>>>>>>>>> > > >> >>>>>>>>>>> > > >> >>>>>>>>>>> On Tue, Apr 8, 2014 at 11:13 AM, Vetoshkin Nikita < > > >> >>>>>>>>>>> nikita.vetosh...@gmail.com> wrote: > > >> >>>>>>>>>>> > > >> >>>>>>>>>>>> I'm not a mesos guy, just very curious. But in my opinion > > >> >>>>> - I > > >> >>>>>>> doubt > > >> >>>>>>>>> it, > > >> >>>>>>>>>>>> HTTP is synchronous request-response protocol. Mesos > needs > > >> >>>>>>>> something > > >> >>>>>>>>>> more > > >> >>>>>>>>>>>> robust for message passing. Websockets anyone? :) > > >> >>>>>>>>>>>> > > >> >>>>>>>>>>>> > > >> >>>>>>>>>>>> On Tue, Apr 8, 2014 at 10:08 PM, Vladimir Vivien > > >> >>>>>>>>>>>> <vladimir.viv...@gmail.com>wrote: > > >> >>>>>>>>>>>> > > >> >>>>>>>>>>>>> Ben / Nikita > > >> >>>>>>>>>>>>> Thanks for the pointers. > > >> >>>>>>>>>>>>> So, (without digging yet) is it a fair summary to say > > >> >>>>> that > > >> >>>>>>>>> libprocess > > >> >>>>>>>>>>>> wraps > > >> >>>>>>>>>>>>> protobufs-encoded calls and push them over HTTP to > > >> >>>>>>> master/slaves > > >> >>>>>>>> ? > > >> >>>>>>>>>> Will > > >> >>>>>>>>>>>>> protobuf (eventually) be supplanted by direct HTTP via > > >> >>>>> REST > > >> >>>>>> or > > >> >>>>>>>>>> similar > > >> >>>>>>>>>>> ? > > >> >>>>>>>>>>>>> > > >> >>>>>>>>>>>>> > > >> >>>>>>>>>>>>> On Mon, Apr 7, 2014 at 2:54 PM, Vetoshkin Nikita < > > >> >>>>>>>>>>>>> nikita.vetosh...@gmail.com > > >> >>>>>>>>>>>>>> wrote: > > >> >>>>>>>>>>>>> > > >> >>>>>>>>>>>>>> Or, just to get to know - you can take tcpdump and > > >> >>>>> take a > > >> >>>>>>> look > > >> >>>>>>>> :) > > >> >>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>> I personally wouldn't call that HTTP. Something > > >> >>>>> "HTTP-like" > > >> >>>>>>>> would > > >> >>>>>>>>>>>>> describe > > >> >>>>>>>>>>>>>> it better. Because it's not request-response. It's > > >> >>>>> just > > >> >>>>>>> message > > >> >>>>>>>>>>>> passing, > > >> >>>>>>>>>>>>> no > > >> >>>>>>>>>>>>>> need to wait for the answer - send new message one > > >> >>>>> after > > >> >>>>>>>> another. > > >> >>>>>>>>>>> Every > > >> >>>>>>>>>>>>>> message is POST with address and message type encoded > > >> >>>>> in > > >> >>>>>> URI: > > >> >>>>>>>>> POST > > >> >>>>>>>>>>>>>> /executor(1)/mesos.internal.RunTaskMessage. Sender is > > >> >>>>>> encoded > > >> >>>>>>>> in > > >> >>>>>>>>>>>>> User-Agent > > >> >>>>>>>>>>>>>> header, e.g: libprocess/slave(1)@127.0.0.1:5051. Body > > >> >>>>>>> contains > > >> >>>>>>>>>>>> protobuf > > >> >>>>>>>>>>>>>> message, Transfer-Encoding is always "chunked". > > >> >>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>> On Mon, Apr 7, 2014 at 10:42 PM, Benjamin Mahler > > >> >>>>>>>>>>>>>> <benjamin.mah...@gmail.com>wrote: > > >> >>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>> Unfortunately you will need to learn this by > > >> >>>>> looking at > > >> >>>>>> the > > >> >>>>>>>>> code > > >> >>>>>>>>>> in > > >> >>>>>>>>>>>>>>> libprocess, as the message passing format is not > > >> >>>>>> explicitly > > >> >>>>>>>>>>>> documented > > >> >>>>>>>>>>>>> at > > >> >>>>>>>>>>>>>>> the current time. > > >> >>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>> Start with calls like ProtobufProcess::send() and > > >> >>>>> dig > > >> >>>>>> your > > >> >>>>>>>> way > > >> >>>>>>>>>>> down. > > >> >>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>> On Sat, Apr 5, 2014 at 7:52 AM, Vladimir Vivien > > >> >>>>>>>>>>>>>>> <vladimir.viv...@gmail.com>wrote: > > >> >>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>>> I was watching this video from > > >> >>>>>>>>>>>>>>>> https://www.youtube.com/watch?v=n5GT7OFSh58fromBen > > >> >>>>>>> where > > >> >>>>>>>> he > > >> >>>>>>>>>>>> talked > > >> >>>>>>>>>>>>>>>> about the wire protocol for Mesos being done in > > >> >>>>>>>>>>>>>>>> HTTP. > > >> >>>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>>> Where can I learn about the low-level wire > > >> >>>>> protocol > > >> >>>>>>> either > > >> >>>>>>>> in > > >> >>>>>>>>>>>>>>> documentation > > >> >>>>>>>>>>>>>>>> or browsing through the code. > > >> >>>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>>> Thanks. > > >> >>>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>>> -- > > >> >>>>>>>>>>>>>>>> Vladimir Vivien > > >> >>>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>>> > > >> >>>>>>>>>>>>>> > > >> >>>>>>>>>>>>> > > >> >>>>>>>>>>>>> > > >> >>>>>>>>>>>>> > > >> >>>>>>>>>>>>> -- > > >> >>>>>>>>>>>>> Vladimir Vivien > > >> >>>>>>>>>>>>> > > >> >>>>>>>>>>>> > > >> >>>>>>>>>>> > > >> >>>>>>>>>> > > >> >>>>>>>>>> > > >> >>>>>>>>>> > > >> >>>>>>>>>> -- > > >> >>>>>>>>>> Vladimir Vivien > > >> >>>>>>>>>> > > >> >>>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> > > >> >>>>>>>> -- > > >> >>>>>>>> Vladimir Vivien > > >> >>>>>>>> > > >> >>>>>>> > > >> >>>>>> > > >> >>>>> > > >> >>>>> > > >> >>>>> > > >> >>>>> -- > > >> >>>>> Vladimir Vivien > > >> >>>>> > > >> >>>> > > >> >>>> > > >> >>> > > >> >> > > >> > > >> > > > > > > > > > -- > > > Vladimir Vivien > > > > > >
