shutdown ExecutorService when shutting down LogManager
diff --git a/asterix-common/src/main/java/edu/uci/ics/asterix/common/api/AsterixThreadExecutor.java b/asterix-common/src/main/java/edu/uci/ics/asterix/common/api/AsterixThreadExecutor.java
index edd4b2a..fb87f5e 100644
--- a/asterix-common/src/main/java/edu/uci/ics/asterix/common/api/AsterixThreadExecutor.java
+++ b/asterix-common/src/main/java/edu/uci/ics/asterix/common/api/AsterixThreadExecutor.java
@@ -36,4 +36,8 @@
     public Future<Object> submit(Callable command) {
         return (Future<Object>) executorService.submit(command);
     }
+    
+    public void shutdown() {
+        executorService.shutdown();
+    }
 }
diff --git a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java
index 4667c80..aef7860 100644
--- a/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java
+++ b/asterix-transactions/src/main/java/edu/uci/ics/asterix/transaction/management/service/logging/LogManager.java
@@ -294,6 +294,7 @@
         if (LOGGER.isLoggable(Level.INFO)) {
             LOGGER.info("LogFlusher thread is terminated.");
         }
+        AsterixThreadExecutor.INSTANCE.shutdown();
     }
 
     private long deleteAllLogFiles() {