[HADOOP-8231] Make topologies easier to set up and debug

• Type: Improvement
• Status: Open
• Priority: Minor
• Resolution: Unresolved
• Affects Version/s: 0.23.1
• Component/s: util
• Assignee: Unassigned
• Reporter: Steve Loughran
• Created: 30/Mar/12 16:20
• Updated: 08/Jul/19 13:27

Description

Topology scripts are a source of problems as they

1. are site-specific.
2. hard to get right.
3. can have adverse consequences on cluster operation when they go wrong.
   This issue is to group up the features needed to make it easier for ops people to get their scripts up and running.

Issue Links

• depends upon: HADOOP-10867 NPE in heartbeat when the configured topology script doesn't exist
• depends upon: HADOOP-7149 Topology script should have some kind of timeout
• depends upon: HADOOP-7423 Document topology script requirements
• is depended upon by: HADOOP-8232 Provide a command line entry point to view/test topology options
• is depended upon by: HADOOP-8928 Add ability to reset topologies on master nodes
• relates to: HDFS-2492 BlockManager cross-rack replication checks only work for ScriptBasedMapping
• relates to: HADOOP-7030 Add TableMapping topology implementation to read host to rack mapping from a file
• relates to: HDFS-12390 Support to refresh DNS to switch mapping
• relates to: HADOOP-7777 Implement a base class for DNSToSwitchMapping implementations that can offer extra topology information

Sub-Tasks

• Provide a command line entry point to view/test topology options: Resolved