HBASE-22363 Remove hardcoded number of read cache block buckets

Signed-off-by: Peter Somogyi <[email protected]>

Author: bijugs

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

@@ -742,7 +742,7 @@ void evict() {
         bucketQueue.add(bucketMulti);
         bucketQueue.add(bucketMemory);
 
-        int remainingBuckets = 3;
+        int remainingBuckets = bucketQueue.size();
 
         BlockBucket bucket;
         while ((bucket = bucketQueue.poll()) != null) {

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

@@ -786,7 +786,7 @@ private void freeSpace(final String why) {
       bucketQueue.add(bucketMulti);
       bucketQueue.add(bucketMemory);
 
-      int remainingBuckets = 3;
+      int remainingBuckets = bucketQueue.size();
       long bytesFreed = 0;
 
       BucketEntryGroup bucketGroup;