+1 to what Alex says. As far as we know, the functionality we use (ephemeral sequential nodes and writing simple data to a znode) is part of the "base API" offered by ZooKeeper and every version would support it. (then again, not a ZK expert here - if anyone knows better, please feel free to correct me).
*Marco Massenzio* *Distributed Systems Engineerhttp://codetrips.com <http://codetrips.com>* On Fri, Sep 25, 2015 at 6:24 AM, Alex Rukletsov <[email protected]> wrote: > James— > > Marco will correct me if I'm wrong, but my understanding is that this > change does *not* impact what ZooKeeper version you can use with Mesos. We > have changed the format of the message stored in ZK from protobuf to JSON. > This message is needed by frameworks for mesos master leader detection. > > HTH, > Alex > > On Fri, Sep 25, 2015 at 11:12 AM, CCAAT <[email protected]> wrote: > >> On 09/25/2015 08:13 AM, Marco Massenzio wrote: >> >>> Folks: >>> >>> as a reminder, please be aware that as of Mesos 0.24.0, as announced >>> back in June, Mesos Master will write its information (`MasterInfo`) to >>> ZooKeeper in JSON format (see below for details). >>> >> >> >> What versions of Zookeeper are supported by this change? That is, what >> is the oldest version of Zookeeper known to work or not work with this >> change in Mesos? >> >> >> James >> >> >> >> >> >>> If your framework relied on parsing the info (either de-serializing the >>> Protocol Buffer or just looking for an "IP-like" string) this change >>> will be a breaking change. >>> >>> Just to confirm (see also Vinod's comments below) any rolling upgrades >>> (i.e., clusters with 0.22+0.23 and 0.23+0.24) of Mesos will just work. >>> >>> This was in conjunction with the HTTP API release and removing the need >>> for non-C++ developers to have to link with libmesos and have to deal >>> with Protocol Buffers. >>> >>> An example of how to access the new format in Python can be found in [0] >>> and we're happy to help with other languages too. >>> Any questions, please just ask. >>> >>> [0] http://github.com/massenz/zk-mesos >>> >>> Marco Massenzio >>> /Distributed Systems Engineer >>> http://codetrips.com/ >>> >>> ---------- Forwarded message ---------- >>> From: *Vinod Kone* <[email protected] <mailto:[email protected]>> >>> Date: Wed, Jun 24, 2015 at 4:17 PM >>> Subject: Re: [Breaking Change 0.24 & Upgrade path] ZooKeeper MasterInfo >>> change. >>> To: dev <[email protected] <mailto:[email protected]>> >>> >>> >>> Just to clarify, any frameworks that are using the Mesos provided >>> bindings >>> (aka libmesos.so) should not worry, as long as the version of the >>> bindings >>> and version of the mesos master are not separated by more than 1 version. >>> In other words, you should be able to live upgrade a cluster from 0.23.0 >>> to >>> 0.24.0. >>> >>> For framework schedulers that don't use the bindings (pesos, jesos etc), >>> it >>> is prudent to add support for JSON formatted ZNODE to their master >>> detection code. >>> >>> Thanks, >>> >>> On Wed, Jun 24, 2015 at 4:10 PM, Marco Massenzio <[email protected] >>> <mailto:[email protected]>> >>> wrote: >>> >>> Folks, >>>> >>>> as heads-up, we are planning to convert the format of the MasterInfo >>>> information stored in ZooKeeper from the Protocol Buffer binary format >>>> to >>>> JSON - this is in conjunction with the HTTP API development, to allow >>>> frameworks *not* to depend on libmesos and other binary dependencies to >>>> interact with Mesos Master nodes. >>>> >>>> > *NOTE* - there is no change in 0.23 (so any Master/Slave/Framework >>> that is >>> > currently working in 0.22 *will continue to work* in 0.23 too) but as >>> of >>> >>>> Mesos 0.24, frameworks and other clients relying on the binary format >>>> will >>>> break. >>>> >>>> The details of the design are in this Google Doc: >>>> >>>> >>>> https://docs.google.com/document/d/1i2pWJaIjnFYhuR-000NG-AC1rFKKrRh3Wn47Y2G6lRE/edit >>>> >>>> the actual work is detailed in MESOS-2340: >>>> https://issues.apache.org/jira/browse/MESOS-2340 >>>> >>>> and the patch (and associated test) are here: >>>> https://reviews.apache.org/r/35571/ >>>> https://reviews.apache.org/r/35815/ >>>> >>>> > *Marco Massenzio* >>> > *Distributed Systems Engineer* >>> > >>> >>> >> >
