[SPARK-7997][CORE] Remove Akka from Spark Core and Streaming

- Remove Akka dependency from core. Note: the streaming-akka project still uses Akka.
- Remove HttpFileServer
- Remove Akka configs from SparkConf and SSLOptions
- Rename `spark.akka.frameSize` to `spark.rpc.message.maxSize`. I think it's still worth to keep this config because using `DirectTaskResult` or `IndirectTaskResult`  depends on it.
- Update comments and docs

Author: Shixiong Zhu <shixiong@databricks.com>

Closes #10854 from zsxwing/remove-akka.

2 files changed, 2 insertions, 2 deletions

diff --git a/mllib/src/main/scala/org/apache/spark/mllib/feature/VectorTransformer.scala b/mllib/src/main/scala/org/apache/spark/mllib/feature/VectorTransformer.scala
index 5778fd1d09..ca7385128d 100644
--- a/mllib/src/main/scala/org/apache/spark/mllib/feature/VectorTransformer.scala
+++ b/mllib/src/main/scala/org/apache/spark/mllib/feature/VectorTransformer.scala
@@ -47,7 +47,7 @@ trait VectorTransformer extends Serializable {
    */
   @Since("1.1.0")
   def transform(data: RDD[Vector]): RDD[Vector] = {
-    // Later in #1498 , all RDD objects are sent via broadcasting instead of akka.
+    // Later in #1498 , all RDD objects are sent via broadcasting instead of RPC.
     // So it should be no longer necessary to explicitly broadcast `this` object.
     data.map(x => this.transform(x))
   }
diff --git a/mllib/src/test/scala/org/apache/spark/mllib/util/LocalClusterSparkContext.scala b/mllib/src/test/scala/org/apache/spark/mllib/util/LocalClusterSparkContext.scala
index 9b2d023bbf..95d874b843 100644
--- a/mllib/src/test/scala/org/apache/spark/mllib/util/LocalClusterSparkContext.scala
+++ b/mllib/src/test/scala/org/apache/spark/mllib/util/LocalClusterSparkContext.scala
@@ -29,7 +29,7 @@ trait LocalClusterSparkContext extends BeforeAndAfterAll { self: Suite =>
     val conf = new SparkConf()
       .setMaster("local-cluster[2, 1, 1024]")
       .setAppName("test-cluster")
-      .set("spark.akka.frameSize", "1") // set to 1MB to detect direct serialization of data
+      .set("spark.rpc.message.maxSize", "1") // set to 1MB to detect direct serialization of data
     sc = new SparkContext(conf)
   }