From c73334a924d2009d136a8ee62278aaac53418a24 Mon Sep 17 00:00:00 2001
From: Lukas Majercak <lukmajercak@gmail.com>
Date: Thu, 14 Nov 2019 09:54:02 -0800
Subject: [PATCH] HADOOP-16705. MBeanInfoBuilder puts unnecessary memory
 pressure on the system with a debug log.

MBeanInfoBuilder's get() method DEBUG logs all the MBeanAttributeInfo attributes that it gathered. This can have a high memory churn that can be easily avoided.
---
 .../java/org/apache/hadoop/metrics2/impl/MBeanInfoBuilder.java  | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MBeanInfoBuilder.java b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MBeanInfoBuilder.java
index 528211913d..cdd0ba4275 100644
--- a/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MBeanInfoBuilder.java
+++ b/hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/metrics2/impl/MBeanInfoBuilder.java
@@ -106,7 +106,7 @@ MBeanInfo get() {
       }
       ++curRecNo;
     }
-    MetricsSystemImpl.LOG.debug(attrs.toString());
+    MetricsSystemImpl.LOG.debug("{}", attrs);
     MBeanAttributeInfo[] attrsArray = new MBeanAttributeInfo[attrs.size()];
     return new MBeanInfo(name, description, attrs.toArray(attrsArray),
                          null, null, null); // no ops/ctors/notifications