第6课：Spark Streaming源码解读之Job动态生成和深度思考
/**
* This class schedules jobs to be run on Spark. It uses the JobGenerator to generate
* the jobs and runs them using a thread pool.
*/
private[streaming]
class JobScheduler(val ssc: StreamingContext) extends Logging {
// Use of ConcurrentHashMap.keySet later causes an odd runtime problem due to Java 7/8 diff
// https://gist.github.com/AlainODea/1375759b8720a3f9f094
private val jobSets: java.util.Map[Time, JobSet] = new ConcurrentHashMap[Time, JobSet]
private val numConcurrentJobs = ssc.conf.getInt("spark.streaming.concurrentJobs", 1)
private val jobExecutor =
ThreadUtils.newDaemonFixedThreadPool(numConcurrentJobs, "streaming-job-executor")
private val jobGenerator = new JobGenerator(this)
val clock = jobGenerator.clock
val listenerBus = new StreamingListenerBus()
// These two are created only when scheduler starts.
// e
