Make query parallelism configurable instead of hardcoding to 10 in HiveInterpreter.java

tw-172-25-131-152 incubator-zeppelin (presto) $ git diff
diff --git a/hive/src/main/java/org/apache/zeppelin/hive/HiveInterpreter.java b/hive/src/main/java/org/apache/zeppelin/hive/HiveInterpreter.java
index 47b97bf..9c3bcc3 100644
--- a/hive/src/main/java/org/apache/zeppelin/hive/HiveInterpreter.java
+++ b/hive/src/main/java/org/apache/zeppelin/hive/HiveInterpreter.java
@@ -52,6 +52,8 @@ public class HiveInterpreter extends Interpreter {
   static final String COMMON_KEY = "common";
   static final String MAX_LINE_KEY = "max_count";
   static final String MAX_LINE_DEFAULT = "1000";
+  static final String MAX_PARALLELISM_KEY = "max_parallelism";
+  static final String MAX_PARALLELISM_DEFAULT = "10";
 
   static final String DEFAULT_KEY = "default";
   static final String DRIVER_KEY = "driver";
@@ -67,6 +69,7 @@ public class HiveInterpreter extends Interpreter {
   static final String UPDATE_COUNT_HEADER = "Update Count";
 
   static final String COMMON_MAX_LINE = COMMON_KEY + DOT + MAX_LINE_KEY;
+  static final String COMMON_MAX_PARALLELISM = COMMON_KEY + DOT + MAX_PARALLELISM_KEY;
 
   static final String DEFAULT_DRIVER = DEFAULT_KEY + DOT + DRIVER_KEY;
   static final String DEFAULT_URL = DEFAULT_KEY + DOT + URL_KEY;
@@ -86,6 +89,7 @@ public class HiveInterpreter extends Interpreter {
         HiveInterpreter.class.getName(),
         new InterpreterPropertyBuilder()
             .add(COMMON_MAX_LINE, MAX_LINE_DEFAULT, "Maximum line of results")
+            .add(COMMON_MAX_PARALLELISM, MAX_PARALLELISM_DEFAULT, "Maximum queries in parallel")
             .add(DEFAULT_DRIVER, "org.apache.hive.jdbc.HiveDriver", "Hive JDBC driver")
             .add(DEFAULT_URL, "jdbc:hive2://localhost:10000", "The URL for HiveServer2.")
             .add(DEFAULT_USER, "hive", "The hive user")
@@ -340,6 +344,14 @@ public class HiveInterpreter extends Interpreter {
         propertiesMap.get(COMMON_KEY).getProperty(MAX_LINE_KEY, MAX_LINE_DEFAULT));
   }
 
+  private int getMaxParallelism() {
+    logger.debug("property: {}", propertiesMap.get(COMMON_KEY));
+    logger.debug(
+      propertiesMap.get(COMMON_KEY).getProperty(MAX_PARALLELISM_KEY, MAX_PARALLELISM_DEFAULT));
+    return Integer.valueOf(
+      propertiesMap.get(COMMON_KEY).getProperty(MAX_PARALLELISM_KEY, MAX_PARALLELISM_DEFAULT));
+  }
+
   public String getPropertyKey(String cmd) {
     int firstLineIndex = cmd.indexOf("\n");
     if (-1 == firstLineIndex) {
@@ -377,7 +389,7 @@ public class HiveInterpreter extends Interpreter {
   @Override
   public Scheduler getScheduler() {
     return SchedulerFactory.singleton().createOrGetParallelScheduler(
-        HiveInterpreter.class.getName() + this.hashCode(), 50);
+        HiveInterpreter.class.getName() + this.hashCode(), getMaxParallelism());
   }
 
   @Override