HBASE-28011 : The logStats about LruBlockCache is not accurate (apache#5344)

Author: guluo2016

hbase-server/src/main/java/org/apache/hadoop/hbase/io/hfile/LruBlockCache.java

@@ -960,12 +960,13 @@ public void run() {
 
   public void logStats() {
     // Log size
-    long totalSize = heapSize();
-    long freeSize = maxSize - totalSize;
-    LruBlockCache.LOG.info("totalSize=" + StringUtils.byteDesc(totalSize) + ", " + "freeSize="
-      + StringUtils.byteDesc(freeSize) + ", " + "max=" + StringUtils.byteDesc(this.maxSize) + ", "
-      + "blockCount=" + getBlockCount() + ", " + "accesses=" + stats.getRequestCount() + ", "
-      + "hits=" + stats.getHitCount() + ", " + "hitRatio="
+    long usedSize = heapSize();
+    long freeSize = maxSize - usedSize;
+    LruBlockCache.LOG.info("totalSize=" + StringUtils.byteDesc(maxSize) + ", " + "usedSize="
+      + StringUtils.byteDesc(usedSize) + ", " + "freeSize=" + StringUtils.byteDesc(freeSize) + ", "
+      + "max=" + StringUtils.byteDesc(this.maxSize) + ", " + "blockCount=" + getBlockCount() + ", "
+      + "accesses=" + stats.getRequestCount() + ", " + "hits=" + stats.getHitCount() + ", "
+      + "hitRatio="
       + (stats.getHitCount() == 0
         ? "0"
         : (StringUtils.formatPercent(stats.getHitRatio(), 2) + ", "))