Closes connection to data source.
Closes connection to data source. invoked in onStop() method of org.apache.gearpump.streaming.source.DataSourceTask
Opens connection to data source invoked in onStart() method of org.apache.gearpump.streaming.source.DataSourceTask
Opens connection to data source invoked in onStart() method of org.apache.gearpump.streaming.source.DataSourceTask
is the task context at runtime
is the start time of system
Reads next message from data source and returns null if no message is available
Reads next message from data source and returns null if no message is available
a org.apache.gearpump.Message or null
Sets store factory which creates a checkpoint store at runtime to checkpoint (timestamp, source_offsets)
AT-LEAST-ONCE API. Represents a data source which allow replaying.
Subclass should be able to replay messages on recovery from the time when an application crashed.