[CASSANDRA-7839] Support standard EC2 naming conventions in Ec2Snitch

• Type: Improvement
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 4.0-alpha1, 4.0
• Impacts: Docs
• Assignee: Jason Brown
• Reporter: Gregory Ramsperger

Authors

Jason Brown

Reviewers

Joey Lynch

• Created: 27/Aug/14 16:00
• Updated: 29/Jun/20 16:03
• Resolved: 17/Apr/18 01:01

Description

The EC2 snitches use datacenter and rack naming conventions inconsistent with those presented in Amazon EC2 APIs as region and availability zone. A discussion of this is found in CASSANDRA-4026. This has not been changed for valid backwards compatibility reasons. Using SnitchProperties, it is possible to switch between the legacy naming and the full, AWS-style naming.

Proposal:

• introduce a property (ec2_naming_scheme) to switch naming schemes.
• default to current/legacy naming scheme
• add support for a new scheme ("standard") which is consistent AWS conventions
  • data centers will be the region name, including the number
  • racks will be the availability zone name, including the region name

Examples:

• * legacy* : datacenter is the part of the availability zone name preceding the last "-" when the zone ends in -1 and includes the number if not -1. Rack is the portion of the availability zone name following the last "-".
  • us-west-1a => dc: us-west, rack: 1a
  • us-west-2b => dc: us-west-2, rack: 2b;
• standard : datacenter is the part of the availability zone name preceding zone letter. rack is the entire availability zone name.
  • us-west-1a => dc: us-west-1, rack: us-west-1a
  • us-west-2b => dc: us-west-2, rack: us-west-2b;

Issue Links

• is related to: CASSANDRA-15878 Ec2Snitch fails on upgrade in legacy mode
• relates to: CASSANDRA-4026 EC2 snitch incorrectly reports regions