Github user kayousterhout commented on a diff in the pull request:
https://github.com/apache/spark/pull/14079#discussion_r90147862
--- Diff:
core/src/main/scala/org/apache/spark/scheduler/BlacklistTracker.scala ---
@@ -17,10 +17,272 @@
package org.apache.spark.scheduler
+import java.util.concurrent.atomic.AtomicReference
+
+import scala.collection.mutable.{ArrayBuffer, HashMap, HashSet}
+
import org.apache.spark.SparkConf
import org.apache.spark.internal.Logging
import org.apache.spark.internal.config
-import org.apache.spark.util.Utils
+import org.apache.spark.util.{Clock, SystemClock, Utils}
+
+/**
+ * BlacklistTracker is designed to track problematic executors and nodes.
It supports blacklisting
+ * executors and nodes across an entire application (with a periodic
expiry). TaskSetManagers add
+ * additional blacklisting of executors and nodes for individual tasks and
stages which works in
+ * concert with the blacklisting here.
+ *
+ * The tracker needs to deal with a variety of workloads, eg.:
+ *
+ * * bad user code -- this may lead to many task failures, but that
should not count against
+ * individual executors
+ * * many small stages -- this may prevent a bad executor for having many
failures within one
+ * stage, but still many failures over the entire application
+ * * "flaky" executors -- they don't fail every task, but are still
faulty enough to merit
+ * blacklisting
+ *
+ * See the design doc on SPARK-8425 for a more in-depth discussion.
+ *
+ * THREADING: As with most helpers of TaskSchedulerImpl, this is not
thread-safe. Though it is
+ * called by multiple threads, callers must already have a lock on the
TaskSchedulerImpl. The
+ * one exception is [[nodeBlacklist()]], which can be called without
holding a lock.
+ */
+private[scheduler] class BlacklistTracker (
+ conf: SparkConf,
+ clock: Clock = new SystemClock()) extends Logging {
+
+ BlacklistTracker.validateBlacklistConfs(conf)
+ private val MAX_FAILURES_PER_EXEC =
conf.get(config.MAX_FAILURES_PER_EXEC)
+ private val MAX_FAILED_EXEC_PER_NODE =
conf.get(config.MAX_FAILED_EXEC_PER_NODE)
+ val BLACKLIST_TIMEOUT_MILLIS = BlacklistTracker.getBlacklistTimeout(conf)
+
+ /**
+ * A map from executorId to information on task failures. Tracks the
time of each task failure,
+ * so that we can avoid blacklisting executors due to failures that are
very far apart. We do not
+ * actively remove from this as soon as tasks hit their timeouts, to
avoid the time it would take
+ * to do so. But it will not grow too large, because as soon as an
executor gets too many
+ * failures, we blacklist the executor and remove its entry here.
+ */
+ private val executorIdToFailureList = new HashMap[String,
ExecutorFailureList]()
--- End diff --
super nit: remove extra space between "new" and "HashMap"
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