manually backup and restore shards before Solr version 5.2

[#1]

Solr core/shard backup and restore function ONLY became available after version 5.2 . See JIRA: https://issues.apache.org/jira/browse/SOLR-6637

To manually backup and restore shards, please follow the steps : Assumes a SolrCloud cluster has 4 cores and 2 node, which 2 cores on each node. (2 shards, with replicationFactor=2) Back-up each node:

http://server1:8983/solr/collection/replication?command=backup&location=location1&name=backup1 

http://server2:8983/solr/collection/replication?command=backup&location=location2&name=backup2

Create new collection with 2 shards and replicationFactor=2

http://server:8983/solr/admin/collections?action=CREATE&name=newCollection&numShards=2&replicationFa...

Restore from each backup:

http://server1:8983/solr/newCollection/replication?command=restore&location=location1&name=backup1 

http://server2:8983/solr/collection/replication?command=restore&location=location2&name=backup2

Add replicas to each shard

http://server:8983/solr/admin/collections?action=ADDREPLICA&collection=newCollection&shard=shard2&no... 

http://server:8983/solr/admin/collections?action=ADDREPLICA&collection=newCollection&shard=shard1&no...

In the API commands where we just have "server" without 1 or 2, it means you can issue the command from either server.