[YARN-4757] [Umbrella] Simplified discovery of services via DNS mechanisms

• Type: New Feature
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 3.1.0
• Labels: oct16-hard
• Target Version/s: 3.1.0
• Release Note: A DNS server backed by yarn service registry is implemented to enable service discovery on YARN using standard DNS lookup.
• Assignee: Unassigned
• Reporter: Vinod Kumar Vavilapalli
• Created: 03/Mar/16 21:04
• Updated: 22/Mar/18 05:53
• Resolved: 06/Nov/17 22:57

Description

[See overview doc at YARN-4692, copying the sub-section (3.2.10.2) to track all related efforts.]

In addition to completing the present story of service­-registry (YARN-913), we also need to simplify the access to the registry entries. The existing read mechanisms of the YARN Service Registry are currently limited to a registry specific (java) API and a REST interface. In practice, this makes it very difficult for wiring up existing clients and services. For e.g, dynamic configuration of dependent end­points of a service is not easy to implement using the present registry­-read mechanisms, without code-changes to existing services.

A good solution to this is to expose the registry information through a more generic and widely used discovery mechanism: DNS. Service Discovery via DNS uses the well-­known DNS interfaces to browse the network for services. YARN-913 in fact talked about such a DNS based mechanism but left it as a future task. (Task) Having the registry information exposed via DNS simplifies the life of services.

Issue Links

• is part of: YARN-4692 [Umbrella] Simplified and first-class support for services in YARN
• is part of: YARN-5079 [Umbrella] Native YARN framework layer for services and beyond
• is required by: SLIDER-1174 Support Tensorflow on Slider
• relates to: YARN-4758 Enable discovery of AMs by containers
• relates to: YARN-7054 Yarn Service Phase 2