Solr failed to switch to the other one in Ambari

[#1]

Hi guys,

we added solr srever in solrCloud，when I want to achieve to HA in solrCloud. but it is failed in transfer. when one is stop , the other one is living and used by Atlas. 

[#2 · Accepted solution]

Hello,

Thank you for reaching out to Cloudera ! 

To achieve HA in SolrCloud, there are 2 concepts - 

1. Multiple Live Solr Instances 

2. Replicas for the Collections

For example, if you have 2 Solr Instances live in SolrCloud, and you have one collection with multiple shards but with 1 replica. In this case, the Collection is not highly available. In event of issue on one Solr Node, the collection will not be functional .

Now, if you have 2 Solr Instances live in SolrCloud, and you have one collection with multiple shards with 2 replicas ( Replicas <= Number of Solr Instances ). In this case, Collection is highly available. In event of issue on one Solr Node, the replicas hosted on other Solr Node will be registered as Active, and will serve client query/updates.

To add replicas to an existing collection, ADDREPLICA [1] API can be used. If you have any questions, please do not hesitate to update this discussion.

[1] https://solr.apache.org/guide/8_4/replica-management.html#addreplica

[#3]

@Joanna, Has the reply helped resolve your issue? If so, please mark the appropriate reply as the solution, as it will make it easier for others to find the answer in the future.