sleep when resource in not satisfy. fix #1522

dolphinscheduler-server/src/main/java/org/apache/dolphinscheduler/server/master/runner/MasterSchedulerThread.java

@@ -98,7 +98,11 @@ public class MasterSchedulerThread implements Runnable {
             InterProcessMutex mutex = null;
             try {
 
-                if(OSUtils.checkResource(masterConfig.getMasterMaxCpuloadAvg(), masterConfig.getMasterReservedMemory())){
+                boolean runCheckFlag = OSUtils.checkResource(masterConfig.getMasterMaxCpuloadAvg(), masterConfig.getMasterReservedMemory());
+                if(!runCheckFlag) {
+                    Thread.sleep(Constants.SLEEP_TIME_MILLIS);
+                    continue;
+                }
                 if (zkMasterClient.getZkClient().getState() == CuratorFrameworkState.STARTED) {
 
                     // create distributed lock with the root node path of the lock space as /dolphinscheduler/lock/masters
@@ -126,11 +130,6 @@ public class MasterSchedulerThread implements Runnable {
                         }
                     }
                 }
-                }
-
-                // accessing the command table every SLEEP_TIME_MILLIS milliseconds
-                Thread.sleep(Constants.SLEEP_TIME_MILLIS);
-
             }catch (Exception e){
                 logger.error("master scheduler thread exception : " + e.getMessage(),e);
             }finally{