[MESOS-2340] Add ability to decode JSON serialized MasterInfo from ZK

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 0.23.0
• Component/s: leader election
• Labels: mesosphere
• Target Version/s: 0.23.0
• Epic Link: Scheduler API v1
• Sprint: Mesosphere Sprint 11, Mesosphere Sprint 12
• Story Points: 5
• Assignee: Marco Massenzio
• Reporter: Zameer Manji
• Created: 10/Feb/15 21:57
• Updated: 26/Nov/18 12:21
• Resolved: 26/Nov/18 12:21

Description

Currently to discover the master a client needs the ZK node location and access to the MasterInfo protobuf so it can deserialize the binary blob in the node.

I think it would be nice to publish JSON (like Twitter's ServerSets) so clients are not tied to protobuf to do service discovery.

This ticket is an intermediate (compatibility) step: we add in 0.23 the ability for the Detector to "understand" JSON *alongside* Protobuf serialized format; this makes it compatible with both earlier versions, as well a future one (most likely, 0.24) that will write the MasterInfo information in JSON format.

Issue Links

• is blocked by: MESOS-2709 Design Master discovery functionality for HTTP-only clients
• is depended upon by: AURORA-1031 Replace libmesos w/ Pesos
• relates to: MESOS-2736 Upgrade the design of MasterInfo
• relates to: MESOS-2298 Provide a Java library for master detection
• relates to: MESOS-2912 Provide a Python library for master detection