[SPARK-6847][CORE][STREAMING] Fix stack overflow issue when updateStateByKey is followed by a checkpointed dstream

Add a local property to indicate if checkpointing all RDDs that are marked with the checkpoint flag, and enable it in Streaming

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #10934 from zsxwing/recursive-checkpoint.

1 files changed, 69 insertions, 0 deletions

diff --git a/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala b/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
index 4a6b91fbc7..786703eb9a 100644
--- a/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
+++ b/streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala
@@ -821,6 +821,75 @@ class CheckpointSuite extends TestSuiteBase with DStreamCheckpointTester
     checkpointWriter.stop()
   }
 
+  test("SPARK-6847: stack overflow when updateStateByKey is followed by a checkpointed dstream") {
+    // In this test, there are two updateStateByKey operators. The RDD DAG is as follows:
+    //
+    //     batch 1            batch 2            batch 3     ...
+    //
+    // 1) input rdd          input rdd          input rdd
+    //       |                  |                  |
+    //       v                  v                  v
+    // 2) cogroup rdd   ---> cogroup rdd   ---> cogroup rdd  ...
+    //       |         /        |         /        |
+    //       v        /         v        /         v
+    // 3)  map rdd ---        map rdd ---        map rdd     ...
+    //       |                  |                  |
+    //       v                  v                  v
+    // 4) cogroup rdd   ---> cogroup rdd   ---> cogroup rdd  ...
+    //       |         /        |         /        |
+    //       v        /         v        /         v
+    // 5)  map rdd ---        map rdd ---        map rdd     ...
+    //
+    // Every batch depends on its previous batch, so "updateStateByKey" needs to do checkpoint to
+    // break the RDD chain. However, before SPARK-6847, when the state RDD (layer 5) of the second
+    // "updateStateByKey" does checkpoint, it won't checkpoint the state RDD (layer 3) of the first
+    // "updateStateByKey" (Note: "updateStateByKey" has already marked that its state RDD (layer 3)
+    // should be checkpointed). Hence, the connections between layer 2 and layer 3 won't be broken
+    // and the RDD chain will grow infinitely and cause StackOverflow.
+    //
+    // Therefore SPARK-6847 introduces "spark.checkpoint.checkpointAllMarked" to force checkpointing
+    // all marked RDDs in the DAG to resolve this issue. (For the previous example, it will break
+    // connections between layer 2 and layer 3)
+    ssc = new StreamingContext(master, framework, batchDuration)
+    val batchCounter = new BatchCounter(ssc)
+    ssc.checkpoint(checkpointDir)
+    val inputDStream = new CheckpointInputDStream(ssc)
+    val updateFunc = (values: Seq[Int], state: Option[Int]) => {
+      Some(values.sum + state.getOrElse(0))
+    }
+    @volatile var shouldCheckpointAllMarkedRDDs = false
+    @volatile var rddsCheckpointed = false
+    inputDStream.map(i => (i, i))
+      .updateStateByKey(updateFunc).checkpoint(batchDuration)
+      .updateStateByKey(updateFunc).checkpoint(batchDuration)
+      .foreachRDD { rdd =>
+        /**
+         * Find all RDDs that are marked for checkpointing in the specified RDD and its ancestors.
+         */
+        def findAllMarkedRDDs(rdd: RDD[_]): List[RDD[_]] = {
+          val markedRDDs = rdd.dependencies.flatMap(dep => findAllMarkedRDDs(dep.rdd)).toList
+          if (rdd.checkpointData.isDefined) {
+            rdd :: markedRDDs
+          } else {
+            markedRDDs
+          }
+        }
+
+        shouldCheckpointAllMarkedRDDs =
+          Option(rdd.sparkContext.getLocalProperty(RDD.CHECKPOINT_ALL_MARKED_ANCESTORS)).
+            map(_.toBoolean).getOrElse(false)
+
+        val stateRDDs = findAllMarkedRDDs(rdd)
+        rdd.count()
+        // Check the two state RDDs are both checkpointed
+        rddsCheckpointed = stateRDDs.size == 2 && stateRDDs.forall(_.isCheckpointed)
+      }
+    ssc.start()
+    batchCounter.waitUntilBatchesCompleted(1, 10000)
+    assert(shouldCheckpointAllMarkedRDDs === true)
+    assert(rddsCheckpointed === true)
+  }
+
   /**
    * Advances the manual clock on the streaming scheduler by given number of batches.
    * It also waits for the expected amount of time for each batch.