HDFS-12546. Ozone: DB listing operation performance improvement. Contributed by Weiwei Yang.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/impl/ContainerManagerImpl.java

@@ -250,7 +250,7 @@ public class ContainerManagerImpl implements ContainerManager {
       // container status.
       MetadataStore metadata = KeyUtils.getDB(containerData, conf);
       List<Map.Entry<byte[], byte[]>> underDeletionBlocks = metadata
-          .getRangeKVs(null, Integer.MAX_VALUE,
+          .getSequentialRangeKVs(null, Integer.MAX_VALUE,
               new MetadataKeyFilters.KeyPrefixFilter(
                   OzoneConsts.DELETING_KEY_PREFIX));
       containerStatus.incrPendingDeletionBlocks(underDeletionBlocks.size());

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/impl/KeyManagerImpl.java

@@ -180,7 +180,7 @@ public class KeyManagerImpl implements KeyManager {
         DFSUtil.string2Bytes(startKey);
     MetadataKeyFilter prefixFilter = new KeyPrefixFilter(prefix);
     List<Map.Entry<byte[], byte[]>> range =
-        db.getRangeKVs(startKeyInBytes, count, prefixFilter);
+        db.getSequentialRangeKVs(startKeyInBytes, count, prefixFilter);
     for (Map.Entry<byte[], byte[]> entry : range) {
       String keyName = KeyUtils.getKeyName(entry.getKey());
       KeyData value = KeyUtils.getKeyData(entry.getValue());

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/container/common/statemachine/background/BlockDeletingService.java

@@ -175,7 +175,7 @@ public class BlockDeletingService extends BackgroundService{
       KeyPrefixFilter filter = new KeyPrefixFilter(
           OzoneConsts.DELETING_KEY_PREFIX);
       List<Map.Entry<byte[], byte[]>> toDeleteBlocks =
-          meta.getRangeKVs(null, blockLimitPerTask, filter);
+          meta.getSequentialRangeKVs(null, blockLimitPerTask, filter);
       if (toDeleteBlocks.isEmpty()) {
         LOG.debug("No under deletion block found in container : {}",
             containerData.getContainerName());

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/ksm/KSMMetadataManagerImpl.java

@@ -347,13 +347,13 @@ public class KSMMetadataManagerImpl implements KSMMetadataManager {
     if (!Strings.isNullOrEmpty(startKey)) {
       //Since we are excluding start key from the result,
       // the maxNumOfBuckets is incremented.
-      rangeResult = store.getRangeKVs(
+      rangeResult = store.getSequentialRangeKVs(
           getDBKeyBytes(volumeName, bucketName, startKey),
           maxKeys + 1, filter);
       //Remove start key from result.
       rangeResult.remove(0);
     } else {
-      rangeResult = store.getRangeKVs(null, maxKeys, filter);
+      rangeResult = store.getSequentialRangeKVs(null, maxKeys, filter);
     }
 
     for (Map.Entry<byte[], byte[]> entry : rangeResult) {
@@ -440,7 +440,7 @@ public class KSMMetadataManagerImpl implements KSMMetadataManager {
     // it should be fine to scan all users in db and return us a
     // list of volume names in string per user.
     List<Map.Entry<byte[], byte[]>> rangeKVs = store
-        .getRangeKVs(null, Integer.MAX_VALUE, filter);
+        .getSequentialRangeKVs(null, Integer.MAX_VALUE, filter);
 
     VolumeList.Builder builder = VolumeList.newBuilder();
     for (Map.Entry<byte[], byte[]> entry : rangeKVs) {
@@ -458,7 +458,7 @@ public class KSMMetadataManagerImpl implements KSMMetadataManager {
     final MetadataKeyFilter deletingKeyFilter =
         new KeyPrefixFilter(DELETING_KEY_PREFIX);
     List<Map.Entry<byte[], byte[]>> rangeResult =
-        store.getRangeKVs(null, count, deletingKeyFilter);
+        store.getSequentialRangeKVs(null, count, deletingKeyFilter);
     for (Map.Entry<byte[], byte[]> entry : rangeResult) {
       KsmKeyInfo info =
           KsmKeyInfo.getFromProtobuf(KeyInfo.parseFrom(entry.getValue()));

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/ozone/scm/container/ContainerMapping.java

@@ -145,7 +145,7 @@ public class ContainerMapping implements Mapping {
       byte[] startKey = startName == null ? null : DFSUtil.string2Bytes(
           startName);
       List<Map.Entry<byte[], byte[]>> range =
-          containerStore.getRangeKVs(startKey, count, prefixFilter);
+          containerStore.getSequentialRangeKVs(startKey, count, prefixFilter);
 
       // Transform the values into the pipelines.
       // TODO: return list of ContainerInfo instead of pipelines.