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cassandraopscenter

Does OpsCenter Community work with a single-node Cassandra cluster?

I am using Ubuntu 15.10 64 bits with OpenJDK 1.8.0_66. Cassandra 3.3 and OpsCenter 5.2.4 are installed from apt packages and running locally. I am using the following sources.

deb http://www.apache.org/dist/cassandra/debian 33x main
deb http://debian.datastax.com/community stable main

The OpsCenter doc says: "In Add Cluster, enter the Hostnames or IP addresses of two or three nodes in the cluster, set the JMX and Native Transport ports, and click Save Cluster".

I have a single-node cluster, so I don't have two or three IP addresses to enter. When I enter the address of the node, I get the following message: "Error creating cluster: Unable to connect to cluster. Error is: Unable to connect to any seed nodes, tried ['127.0.0.1']".

I am using the default ports. netstat -an gives among others the following lines.

tcp        0      0 127.0.0.1:7199          0.0.0.0:*               LISTEN
tcp6       0      0 127.0.0.1:9042          :::*                    LISTEN

nodetool status is working fine.

$ nodetool status
Datacenter: datacenter1
=======================
Status=Up/Down
|/ State=Normal/Leaving/Joining/Moving
--  Address    Load       Tokens       Owns    Host ID                               Rack
UN  127.0.0.1  201.17 KB  256          ?       04da2c59-1a88-4ed3-9af9-8f64ae27e9ac  rack1

Note: Non-system keyspaces don't have the same replication settings, effective ownership information is meaningless

So is cqlsh.

$ cqlsh
Connected to Test Cluster at 127.0.0.1:9042.
[cqlsh 5.0.1 | Cassandra 3.3 | CQL spec 3.4.0 | Native protocol v4]
Use HELP for help.
cqlsh>

After looking at other questions I tried uncommenting the following in /etc/cassandra/cassandra-env.sh. I tried both localhost and 127.0.0.1. It did not help.

JVM_OPTS="$JVM_OPTS -Djava.rmi.server.hostname=<hostname>"

There is nothing in /var/log/cassandra/debug.log or /var/log/cassandra/system.log when the connection attempts fail. The only log messages are from Cassandra starting/stopping.

Is it possible at all to use OpsCenter with a single-node cluster? If so, what might I be missing?

Solution

  • Cassandra 3.3 and OpsCenter 5.2.4

    You're out of luck, OpsCenter 5.x only work for Cassandra 2.1 branch and the future OpsCenter 6.x that will be compatible with Cassandra 3.x branch will only be available wit the Datastax Enterprise version, read this: http://docs.datastax.com/en/opscenter/5.2/opsc/opscPolicyChanges.html