N1QL query is failing in a bucket replica with timeout exception

[vsr1]

Couchbase SDKs

N1QL replica read for resiliency?

Hi all, As far as I understand, N1QL queries run on the active data nodes and not replicas. My question is: In the case of a data node failure (but before the failover-rebalance process), is it possible to run queries from Java SDK so that the query processes data from replica vBuckets for substituting unreachable active vBuckets? This way the application could still answer queries with full functionality (although data may partially be stale). The replica read function works for explicit key…

How getFromReplica works ? between nodes or between Data Centers?

I have One DataCenter with 3 nodes, and another one DataCenter with cluster and 3 nodes placed in AWS, for example. 1DC and 2DC are linked with bi-directional replication. When bucket.get(key) fails with connection timeout, ( Am I right that it fails only if all 3 nodes are failed? ) then we can try to get object as bucket.getFromReplica(key. ReplicaMode). Where it tries to get object from? from another Data Center or from another node inside of current data center ? I think it is the firs…

Couchbase SDK 2 : bulk read operations , how to failover to replicas

We are in the process of refactoring a benchmark tool migrating from Couchbase Client 2 to new CouchBase SDK 2. Previous version has following “bulk get” logic to retrive keys in bulk and if it fails reading from the master, there is a failover to read from the “replicas” Legacy code : List<Map.Entry<String, OperationFuture<CASValue<JsonNode>>>> futures = new java.util.ArrayList<>(keys.size()); for (String key : keys) { futures.add(new AbstractMap.SimpleImm…

Failure Considerations | Couchbase Docs