[SOLR-12536] Enhance autoscaling policy to equally distribute replicas on the basis of arbitrary properties

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 7.5, 8.0
• Component/s: AutoScaling
• Assignee: Noble Paul
• Reporter: Noble Paul
• Created: 04/Jul/18 03:15
• Updated: 08/Jun/19 15:03
• Resolved: 27/Jul/18 02:38

Description

example:1

{"replica" : "#EQUAL"  , "shard" : "#EACH" , "port" : "#EACH" }
//if the ports are "8983", "7574", "7575", the above rule is equivalent to
{"replica" : "#EQUAL"  , "shard" : "#EACH" , "port" : ["8983", "7574", "7575"]}

case 1: numShards =2, replicationFactor=3 . In this case all the nodes are divided into 3 buckets each containing nodes in that port. Each bucket must contain 3 * 2 /3 =2 replicas

 

example : 2

{"replica" : "#EQUAL"  , "shard" : "#EACH" , "sysprop.zone" : "#EACH" }
//if the zones are "east_1", "east_2", "west_1", the above rule is equivalent to
{"replica" : "#EQUAL"  , "shard" : "#EACH" , "sysprop.zone" : ["east_1", "east_2", "west_1"]}

The behavior is similar to example 1 , just that in this case we apply it to a system property