metrics

Type Members

1. trait CCSTimer extends Timer

   

2. class CassandraConnectorSource extends Source

   

   This class is a Source implementation for Cassandra Connector related Codahale metrics.

   This class is a Source implementation for Cassandra Connector related Codahale metrics. It is automatically instantiated and registered by Spark metrics system if this source is specified in metrics configuration file.

   Spark instantiates this class when SparkEnv is started. There can be only a single instance of SparkEnv so there can be at most a single active instance of CassandraConnectorSource. The active instance is assigned to CassandraConnectorSource._instance so that it can be retrieved from anywhere by CassandraConnectorSource.instance method. We need this because we have to access the meters from the task execution.

3. sealed trait InputMetricsUpdater extends MetricsUpdater

   

   A trait that provides a method to update read metrics which are collected for connector related tasks.

   A trait that provides a method to update read metrics which are collected for connector related tasks. The appropriate instance is created by the companion object.

   Instances of this trait are not thread-safe. They do not need to because a single instance should be created for each Cassandra read task. This remains valid as long as Cassandra read tasks are single-threaded.

4. trait MetricsUpdater extends AnyRef

   

   The base trait for metrics updaters implementations.

   The base trait for metrics updaters implementations. The metrics updater is an object which provides a unified way to update all the relevant metrics which are collected for the particular type of activity. The connector provides InputMetricsUpdater and OutputMetricsUpdater which are aimed to update all the read and write metrics respectively.

5. sealed trait OutputMetricsUpdater extends MetricsUpdater

   

   A trait that provides a method to update write metrics which are collected for connector related tasks.

   A trait that provides a method to update write metrics which are collected for connector related tasks. The appropriate instance is created by the companion object.

   Instances of OutputMetricsUpdater are thread-safe, because the Cassandra write task implementation is multi-threaded.

6. trait SimpleTimer extends Timer

   

7. trait Timer extends AnyRef

   

   Timer mixin allows to measure the time of a task - or, in other words - the time from creating an instance to calling com.codahale.metrics.Timer.Context.stop method.