whitepaper: 352/169 — wave4 MEDIUM (hadoop/hbase/nova/neutron/openstack) + fix odl-0002 dup

defects/hbase/patch/hbase-0001.patch

@@ -0,0 +1,28 @@
+--- a/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/DefaultStoreFileManager.java
++++ b/hbase-server/src/main/java/org/apache/hadoop/hbase/regionserver/DefaultStoreFileManager.java
+@@ -17,6 +17,7 @@ import java.util.ArrayList;
+ import java.util.Collection;
+ import java.util.Iterator;
+ import java.util.List;
++import java.util.HashSet;
++import java.util.Set;
+ import java.util.stream.Collectors;
+
+ // ... (other imports unchanged)
+
+@@ -229,9 +230,11 @@ public class DefaultStoreFileManager implements StoreFileManager {
+   @Override
+   public Collection<HStoreFile> getUnneededFiles(long maxTs, List<HStoreFile> filesCompacting) {
+     ImmutableList<HStoreFile> files = storeFiles.all;
++    // Build a HashSet once for O(1) membership test inside the stream.
++    // Without this, filesCompacting.contains() is O(C) per file — O(F*C) total.
++    Set<HStoreFile> compactingSet = new HashSet<>(filesCompacting);
+     // 1) We can never get rid of the last file which has the maximum seqid.
+     // 2) Files that are not the latest can't become one due to (1), so the rest are fair game.
+     return files.stream().limit(Math.max(0, files.size() - 1)).filter(sf -> {
+       long fileTs = sf.getReader().getMaxTimestamp();
+-      if (fileTs < maxTs && !filesCompacting.contains(sf)) {
++      if (fileTs < maxTs && !compactingSet.contains(sf)) {
+         LOG.info("Found an expired store file {} whose maxTimestamp is {}, which is below {}",
+           sf.getPath(), fileTs, maxTs);
+         return true;