[
https://issues.apache.org/jira/browse/SOLR-11985?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16524514#comment-16524514
]
ASF subversion and git services commented on SOLR-11985:
--------------------------------------------------------
Commit e2ac4ab4799322c573a9ada771b2c42ea1eb0b82 in lucene-solr's branch
refs/heads/branch_7x from [~noble.paul]
[ https://git-wip-us.apache.org/repos/asf?p=lucene-solr.git;h=e2ac4ab ]
SOLR-11985: ref guide
SOLR-12511: ref guide
SOLR-12517: ref guide
> Allow percentage in replica attribute in policy
> -----------------------------------------------
>
> Key: SOLR-11985
> URL: https://issues.apache.org/jira/browse/SOLR-11985
> Project: Solr
> Issue Type: New Feature
> Security Level: Public(Default Security Level. Issues are Public)
> Components: AutoScaling, SolrCloud
> Reporter: Shalin Shekhar Mangar
> Assignee: Noble Paul
> Priority: Major
> Fix For: master (8.0), 7.5
>
> Attachments: SOLR-11985.patch, SOLR-11985.patch
>
>
> Today we can only specify an absolute number in the 'replica' attribute in
> the policy rules. It'd be useful to write a percentage value to make certain
> use-cases easier. For example:
> {code:java}
> // Keep a third of the the replicas of each shard in east region
> {"replica" : "<34%", "shard" : "#EACH", "sysprop:region": "east"}
> // Keep two thirds of the the replicas of each shard in west region
> {"replica" : "<67%", "shard" : "#EACH", "sysprop:region": "west"}
> {code}
> Today the above must be represented by different rules for each collection if
> they have different replication factors. Also if the replication factor
> changes later, the absolute value has to be changed in tandem. So expressing
> a percentage removes both of these restrictions.
> This feature means that the value of the attribute {{"replica"}} is only
> available just in time. We call such values {{"computed values"}} . The
> computed value for this attribute depends on other attributes as well.
> Take the following 2 rules
> {code:java}
> //example 1
> {"replica" : "<34%", "shard" : "#EACH", "sysprop:region": "east"}
> //example 2
> {"replica" : "<34%", "sysprop:region": "east"}
> {code}
> assume we have collection {{"A"}} with 2 shards and {{replicationFactor=3}}
> *example 1* would mean that the value of replica is computed as
> {{3 * 34 / 100 = 1.02}}
> Which means *_for each shard_* keep less than 1.02 replica in east
> availability zone
>
> *example 2* would mean that the value of replica is computed as
> {{3 * 2 * 34 / 100 = 2.04}}
>
> which means _*for each collection*_ keep less than 2.04 replicas on east
> availability zone
--
This message was sent by Atlassian JIRA
(v7.6.3#76005)
---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]
