change iops limit for compaction from 50 to 30

server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java

diff --git a/server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java b/server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java
index ffed1b6..0313daf 100644
--- a/server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java
+++ b/server/src/main/java/org/apache/iotdb/db/conf/IoTDBConfig.java
@@ -659,7 +659,7 @@
   private long mergeIntervalSec = 0L;
 
   /** The limit of io rate can reach per second */
-  private int compactionIORatePerSec = 50;
+  private int compactionIORatePerSec = 30;
 
   /**
    * How many thread will be set up to perform compaction, 10 by default. Set to 1 when less than or