Is there a way to query solr "leader" directly using solrj?

Question

I'm having a single shard and 1 leader & 1 replica architecture. When using "CloudSolrClient", queries are being distributed to both leader and replica. But is there a way to point it only to leader(using zookeeper) other than finding the leader manually and building the query?

What is the need for such use case when deployed in cloud mode. ? Why don't you deploy single standalone solr server. — Shivakumar ss, Dec 07 '16 at 13:05
Another option is in solrj create instance of httpsolrclient pointing to your leader. This will by pass your zookeeper. — Shivakumar ss, Dec 07 '16 at 13:07
@ShivaKumarSS We are facing some issue during "merge"(merging old document with new document). So during indexing, we want the queries to point leader directly when finding old document (for merge). — Riya, Dec 07 '16 at 13:11
@ShivaKumarSS But in case of leader going down(for some reason), and the replica taking place as a leader, we have to change the httpsolr URL manually. so is there is way to use zookeeper for this?so that it automatically take cares? — Riya, Dec 07 '16 at 13:15

score 0 · Answer 1 · answered Dec 29 '16 at 08:45

It's possible to get the Shards leader in SolrJ and there are several scenarios where this is useful, like for instance when you need to perform a backup programmatically (see example in Solr in Action book). Here is the relevant code I use:

private final String COLLECTION_NAME = "myCollection";
private final String ZOOKEPER_CLIENT_TIMEOUT_MS = "1000000"

private Map<String, String> getShardLeaders(CloudSolrServer cloudSolrServer) throws InterruptedException, KeeperException {
        Map<String, String> shardleaders = new TreeMap<String, String>();
        ZkStateReader zkStateReader = cloudSolrServer.getZkStateReader();
        for (Slice slice : zkStateReader.getClusterState().getSlices(COLLECTION_NAME)) {
            shardleaders.put(slice.getName(), zkStateReader.getLeaderUrl(COLLECTION_NAME, slice.getName(), ZOOKEPER_CLIENT_TIMEOUT_MS));
        }
        return shardleaders;
    }

Is there a way to query solr "leader" directly using solrj?

1 Answers1