This article discusses the root cause for a DataStax Enterprise node failing to startup in non-Analytics mode.

Symptoms

When attempting to startup a DSE node in real-time Cassandra mode only, DSE fails to start with a runtime exception. Below are sample entries from a DSE 4.8.6 system.log:

ERROR [main] 2016-04-28 20:14:23,324  DseDaemon.java:359 - Unable to start DSE server.
java.lang.RuntimeException: com.datastax.bdp.plugin.PluginManager$PluginActivationException: Plugin activation failed
        at com.datastax.bdp.plugin.PluginManager.activate(PluginManager.java:170) ~[dse-core-4.8.6.jar:4.8.6]
        at com.datastax.bdp.plugin.PluginManager.preStart(PluginManager.java:88) ~[dse-core-4.8.6.jar:4.8.6]
        at com.datastax.bdp.server.DseDaemon.preStart(DseDaemon.java:383) ~[dse-core-4.8.6.jar:4.8.6]
        at com.datastax.bdp.server.DseDaemon.start(DseDaemon.java:352) ~[dse-core-4.8.6.jar:4.8.6]
        at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:577) [cassandra-all-2.1.13.1218.jar:2.1.13.1218]
        at com.datastax.bdp.DseModule.main(DseModule.java:74) [dse-core-4.8.6.jar:4.8.6]
Caused by: com.datastax.bdp.plugin.PluginManager$PluginActivationException: Plugin activation failed
        at com.datastax.bdp.plugin.PluginManager.activateDirect(PluginManager.java:310) ~[dse-core-4.8.6.jar:4.8.6]
        at com.datastax.bdp.plugin.PluginManager.activate(PluginManager.java:162) ~[dse-core-4.8.6.jar:4.8.6]
        ... 5 common frames omitted
Caused by: java.lang.RuntimeException: SparkApplicationInfoRollupPlugin cannot be used in non-Spark node.
        at com.datastax.bdp.spark.reporting.SparkApplicationInfoRollupPlugin.init(SparkApplicationInfoRollupPlugin.java:34) ~[dse-spark-4.8.6.jar:4.8.6]
        at com.datastax.bdp.reporting.snapshots.AbstractSnapshotInfoPlugin.setupSchema(AbstractSnapshotInfoPlugin.java:57) ~[dse-core-4.8.6.jar:4.8.6]
        at com.datastax.bdp.plugin.PluginManager.initialize(PluginManager.java:359) ~[dse-core-4.8.6.jar:4.8.6]
        at com.datastax.bdp.plugin.PluginManager.activateDirect(PluginManager.java:289) ~[dse-core-4.8.6.jar:4.8.6]
        ... 6 common frames omitted

Cause

The issue occurs because some Analytics options have been enabled in dse.yaml despite the node not being started up in Analytics mode, for example:

# Spark cluster summary stats options
spark_cluster_info_options:
    enabled: true
...

# Spark application stats options
spark_application_info_options:
    enabled: true
...

As a result, the Spark plugins are getting activated at startup:

INFO  [main] 2016-04-28 20:13:57,261  Workload.java:85 - Setting my workload to Cassandra
...
INFO  [main] 2016-04-28 20:14:22,759  PluginBean.java:54 - SparkClusterInfo plugin is now enabled
INFO  [main] 2016-04-28 20:14:22,759  AsyncSnapshotInfoBean.java:52 - SparkClusterInfo plugin using 1 async writers
INFO  [main] 2016-04-28 20:14:22,760  SnapshotInfoBean.java:58 - SparkClusterInfo refresh rate set to 10000 (was 0)
INFO  [main] 2016-04-28 20:14:22,777  HiveMetaStorePlugin.java:50 - Hive metastore version: 1
INFO  [main] 2016-04-28 20:14:22,782  NodeObjectLatencyPlugin.java:56 - Initializing data object io tracker plugin
INFO  [main] 2016-04-28 20:14:22,788  PluginBean.java:54 - SparkApplicationInfo plugin is now enabled
INFO  [main] 2016-04-28 20:14:22,789  SnapshotInfoBean.java:58 - SparkApplicationInfo refresh rate set to 10000 (was 0)

Solution

Since the Spark options are only valid when the node is started in Analytics mode, update dse.yaml and disable them as follows:

# Spark cluster summary stats options
spark_cluster_info_options:
    enabled: false
...

# Spark application stats options
spark_application_info_options:
    enabled: false
...

This should allow DSE to startup as a Cassandra real-time mode only.

See also

DataStax doc - Monitoring Spark with Spark Performance Objects