[accumulo] branch elasticity updated: handles case where location is not required in root tablet cache (#3421)

[kt...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

kturner pushed a commit to branch elasticity
in repository https://gitbox.apache.org/repos/asf/accumulo.git


The following commit(s) were added to refs/heads/elasticity by this push:
     new b080ce7aa1 handles case where location is not required in root tablet cache (#3421)
b080ce7aa1 is described below

commit b080ce7aa1bfa6521fe5e307b0784c8221c560a1
Author: Keith Turner <kt...@apache.org>
AuthorDate: Tue May 23 08:53:56 2023 -0400

    handles case where location is not required in root tablet cache (#3421)
    
    The root tablet client cache was not handling request that did not
    require a location.  Adds support for handling that case in a manner
    that is similar to the non-root tablet client cache.
    
    fixes #3420
---
 .../core/clientImpl/ClientTabletCache.java         |  1 -
 .../core/clientImpl/RootClientTabletCache.java     | 33 ++++++++++------------
 2 files changed, 15 insertions(+), 19 deletions(-)

diff --git a/core/src/main/java/org/apache/accumulo/core/clientImpl/ClientTabletCache.java b/core/src/main/java/org/apache/accumulo/core/clientImpl/ClientTabletCache.java
index 8cea7ad8e1..71e0510978 100644
--- a/core/src/main/java/org/apache/accumulo/core/clientImpl/ClientTabletCache.java
+++ b/core/src/main/java/org/apache/accumulo/core/clientImpl/ClientTabletCache.java
@@ -105,7 +105,6 @@ public abstract class ClientTabletCache {
       throws AccumuloException, AccumuloSecurityException, TableNotFoundException,
       InvalidTabletHostingRequestException;
 
-  // ELASTICITY_TODO rename to findTablets
   /**
    * <p>
    * This method finds what tablets overlap a given set of ranges, passing each range and its
diff --git a/core/src/main/java/org/apache/accumulo/core/clientImpl/RootClientTabletCache.java b/core/src/main/java/org/apache/accumulo/core/clientImpl/RootClientTabletCache.java
index ed8a6e4da2..dcdb6a2625 100644
--- a/core/src/main/java/org/apache/accumulo/core/clientImpl/RootClientTabletCache.java
+++ b/core/src/main/java/org/apache/accumulo/core/clientImpl/RootClientTabletCache.java
@@ -27,6 +27,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Map;
+import java.util.Optional;
 import java.util.function.BiConsumer;
 
 import org.apache.accumulo.core.Constants;
@@ -45,8 +46,6 @@ import org.apache.hadoop.io.Text;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import com.google.common.base.Preconditions;
-
 public class RootClientTabletCache extends ClientTabletCache {
 
   private final TabletServerLockChecker lockChecker;
@@ -74,18 +73,17 @@ public class RootClientTabletCache extends ClientTabletCache {
   public List<Range> findTablets(ClientContext context, List<Range> ranges,
       BiConsumer<CachedTablet,Range> rangeConsumer, LocationNeed locationNeed) {
 
-    // only expect the hosted case so this code only handles that, so throw an exception is
-    // something else is seen
-    Preconditions.checkArgument(locationNeed == LocationNeed.REQUIRED);
-
     CachedTablet rootCachedTablet = getRootTabletLocation(context);
-    if (rootCachedTablet != null) {
+
+    if (rootCachedTablet.getTserverLocation().isEmpty() && locationNeed == LocationNeed.REQUIRED) {
+      // there is no location and one is required so return all ranges as failures
+      return ranges;
+    } else {
       for (Range range : ranges) {
         rangeConsumer.accept(rootCachedTablet, range);
       }
       return Collections.emptyList();
     }
-    return ranges;
   }
 
   @Override
@@ -125,7 +123,8 @@ public class RootClientTabletCache extends ClientTabletCache {
     }
 
     if (loc == null || loc.getType() != LocationType.CURRENT) {
-      return null;
+      return new CachedTablet(RootTable.EXTENT, Optional.empty(), Optional.empty(),
+          TabletHostingGoal.ALWAYS);
     }
 
     String server = loc.getHostPort();
@@ -133,25 +132,23 @@ public class RootClientTabletCache extends ClientTabletCache {
     if (lockChecker.isLockHeld(server, loc.getSession())) {
       return new CachedTablet(RootTable.EXTENT, server, loc.getSession(), TabletHostingGoal.ALWAYS);
     } else {
-      return null;
+      return new CachedTablet(RootTable.EXTENT, Optional.empty(), Optional.empty(),
+          TabletHostingGoal.ALWAYS);
     }
   }
 
   @Override
   public CachedTablet findTablet(ClientContext context, Text row, boolean skipRow,
       LocationNeed locationNeed) {
-    // only expect the hosted case so this code only handles that, so throw an exception is
-    // something else is seen
-    Preconditions.checkArgument(locationNeed == LocationNeed.REQUIRED);
 
-    CachedTablet location = getRootTabletLocation(context);
+    CachedTablet cachedTablet = getRootTabletLocation(context);
+
     // Always retry when finding the root tablet
-    while (location == null) {
+    while (cachedTablet.getTserverLocation().isEmpty() && locationNeed == LocationNeed.REQUIRED) {
       sleepUninterruptibly(500, MILLISECONDS);
-      location = getRootTabletLocation(context);
+      cachedTablet = getRootTabletLocation(context);
     }
 
-    return location;
+    return cachedTablet;
   }
-
 }