[SPARK-14636] Add minimum memory checks for drivers and executors

## What changes were proposed in this pull request?

Implement the same memory size validations for the StaticMemoryManager (Legacy) as the UnifiedMemoryManager has.

## How was this patch tested?

Manual tests were done in CDH cluster.

Test with small executor memory:
`
spark-submit --class org.apache.spark.examples.SparkPi --deploy-mode client --master yarn --executor-memory 15m --conf spark.memory.useLegacyMode=true /opt/cloudera/parcels/CDH/lib/spark/examples/lib/spark-examples*.jar 10
`

Exception thrown:
```
ERROR spark.SparkContext: Error initializing SparkContext.
java.lang.IllegalArgumentException: Executor memory 15728640 must be at least 471859200. Please increase executor memory using the --executor-memory option or spark.executor.memory in Spark configuration.
	at org.apache.spark.memory.StaticMemoryManager$.org$apache$spark$memory$StaticMemoryManager$$getMaxExecutionMemory(StaticMemoryManager.scala:127)
	at org.apache.spark.memory.StaticMemoryManager.<init>(StaticMemoryManager.scala:46)
	at org.apache.spark.SparkEnv$.create(SparkEnv.scala:352)
	at org.apache.spark.SparkEnv$.createDriverEnv(SparkEnv.scala:193)
	at org.apache.spark.SparkContext.createSparkEnv(SparkContext.scala:289)
	at org.apache.spark.SparkContext.<init>(SparkContext.scala:462)
	at org.apache.spark.examples.SparkPi$.main(SparkPi.scala:29)
	at org.apache.spark.examples.SparkPi.main(SparkPi.scala)
	at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
	at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
	at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
	at java.lang.reflect.Method.invoke(Method.java:606)
	at org.apache.spark.deploy.SparkSubmit$.org$apache$spark$deploy$SparkSubmit$$runMain(SparkSubmit.scala:731)
	at org.apache.spark.deploy.SparkSubmit$.doRunMain$1(SparkSubmit.scala:181)
	at org.apache.spark.deploy.SparkSubmit$.submit(SparkSubmit.scala:206)
	at org.apache.spark.deploy.SparkSubmit$.main(SparkSubmit.scala:121)
	at org.apache.spark.deploy.SparkSubmit.main(SparkSubmit.scala)
```

Author: Peter Ableda <[email protected]>

Closes apache#12395 from peterableda/SPARK-14636.

core/src/main/scala/org/apache/spark/memory/StaticMemoryManager.scala

@@ -104,6 +104,8 @@ private[spark] class StaticMemoryManager(
 
 private[spark] object StaticMemoryManager {
 
+  private val MIN_MEMORY_BYTES = 32 * 1024 * 1024
+
   /**
    * Return the total amount of memory available for the storage region, in bytes.
    */
@@ -119,6 +121,20 @@ private[spark] object StaticMemoryManager {
    */
   private def getMaxExecutionMemory(conf: SparkConf): Long = {
     val systemMaxMemory = conf.getLong("spark.testing.memory", Runtime.getRuntime.maxMemory)
+
+    if (systemMaxMemory < MIN_MEMORY_BYTES) {
+      throw new IllegalArgumentException(s"System memory $systemMaxMemory must " +
+        s"be at least $MIN_MEMORY_BYTES. Please increase heap size using the --driver-memory " +
+        s"option or spark.driver.memory in Spark configuration.")
+    }
+    if (conf.contains("spark.executor.memory")) {
+      val executorMemory = conf.getSizeAsBytes("spark.executor.memory")
+      if (executorMemory < MIN_MEMORY_BYTES) {
+        throw new IllegalArgumentException(s"Executor memory $executorMemory must be at least " +
+          s"$MIN_MEMORY_BYTES. Please increase executor memory using the " +
+          s"--executor-memory option or spark.executor.memory in Spark configuration.")
+      }
+    }
     val memoryFraction = conf.getDouble("spark.shuffle.memoryFraction", 0.2)
     val safetyFraction = conf.getDouble("spark.shuffle.safetyFraction", 0.8)
     (systemMaxMemory * memoryFraction * safetyFraction).toLong