CODEWITHSUNDEEP
apache-sparkdatastaxdatastax-enterprise
jguerra
jguerra

Reputation: 147

Puzzeling Spark warning (DSE 4.8.4)

I've just came across a weird warning on Spark console (DSE 4.8.4) that I don't have any clue where it comes from. It seems it's picking up a datacenter DC1 from somewhere. The thing is, I don't have any Datacenter called DC1. I have three datacenters but none is tagged like that.

WARN 2016-01-21 05:26:54 com.datastax.driver.core.ReplicationStrategy$NetworkTopologyStrategy: Error while computing token map for datacenter DC1: could not achieve replication factor 1 (found 0 replicas only), check your keyspace replication settings. Note that this can affect the performance of the driver.

Upvotes: 4

Views: 772

Answers (1)

Andy Tolbert
Andy Tolbert

Reputation: 11638

This is a message being emitted by the java driver that indicates that one of your keyspaces includes 'DC1' in its replication factor. This can cause slow initialization in the java driver if you have a lot of nodes or are using vnodes since it involves a worse case performance to try to find matching replicas (this is fixed but still logged in java 2.0.11 / 2.1.8, JAVA-859).

To figure out which keyspace this is, execute describe schema in a cqlsh session which should print out your entire schema definition. Look for create keyspace definitions and observe their replication_strategy, i.e.:

CREATE KEYSPACE myks WITH replication = {'class': 'NetworkTopologyStrategy', 'DC1': '3'}  AND durable_writes = true;

In a future version of the java driver, it will include the keyspace name that has the invalid replication factor (JAVA-989).

Upvotes: 3

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