SPARK-3178 setting SPARK_WORKER_MEMORY to a value without a label (m or g) sets the worker memory limit to zero

core/src/main/scala/org/apache/spark/deploy/worker/WorkerArguments.scala

@@ -19,8 +19,8 @@ package org.apache.spark.deploy.worker
 
 import java.lang.management.ManagementFactory
 
-import org.apache.spark.util.{IntParam, MemoryParam, Utils}
 import org.apache.spark.SparkConf
+import org.apache.spark.util.{IntParam, MemoryParam, Utils}
 
 /**
  * Command-line parser for the worker.
@@ -56,6 +56,8 @@ private[spark] class WorkerArguments(args: Array[String], conf: SparkConf) {
 
   parse(args.toList)
 
+  checkWorkerMemory()
+
   def parse(args: List[String]): Unit = args match {
     case ("--ip" | "-i") :: value :: tail =>
       Utils.checkHost(value, "ip no longer supported, please use hostname " + value)
@@ -153,4 +155,11 @@ private[spark] class WorkerArguments(args: Array[String], conf: SparkConf) {
     // Leave out 1 GB for the operating system, but don't return a negative memory size
     math.max(totalMb - 1024, 512)
   }
+
+  def checkWorkerMemory(): Unit = {
+    if (memory <= 0) {
+      val message = "Memory can't be 0, missing a M or G on the end of the memory specification?"
+      throw new IllegalStateException(message)
+    }
+  }
 }

core/src/test/scala/org/apache/spark/deploy/worker/WorkerArgumentsTest.scala

@@ -0,0 +1,60 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements.  See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache License, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License.  You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+
+package org.apache.spark.deploy.worker
+
+import org.apache.spark.SparkConf
+import org.scalatest.FunSuite
+
+
+class WorkerArgumentsTest extends FunSuite {
+
+  test("Memory can't be set to 0 when cmd line args leave off M or G") {
+    val conf = new SparkConf
+    val args = Array("-m", "10000", "spark://localhost:0000  ")
+    intercept[IllegalStateException] {
+      new WorkerArguments(args, conf)
+    }
+  }
+
+
+/* For this test an environment property for SPARK_WORKER_MEMORY was set
+   in the scalatest-maven-plugin under the <environmentVariables> and then
+   run manually
+      <SPARK_WORKER_MEMORY>100000</SPARK_WORKER_MEMORY>
+ */
+
+//  test("Memory can't be set to 0 when SPARK_WORKER_MEMORY env property leaves off M or G") {
+//    val conf = new SparkConf
+//    val args = Array("spark://localhost:0000  ")
+//
+//    intercept[IllegalStateException] {
+//      new WorkerArguments(args, conf)
+//    }
+//  }
+
+  test("Check memory correctly set from args with M appended to memory value") {
+    val conf = new SparkConf
+    val args = Array("-m", "10000M", "spark://localhost:0000  ")
+
+    val workerArgs = new WorkerArguments(args, conf)
+    assert(workerArgs.memory === 10000)
+
+  }
+
+}