(accumulo) branch elasticity updated: use conditional mutations to remove hosting request (#4635)

[kturner]

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 6210f6747a use conditional mutations to remove hosting request (#4635)
6210f6747a is described below

commit 6210f6747a9e54a62b66980738023154bfcd803f
Author: Keith Turner <ktur...@apache.org>
AuthorDate: Wed Jun 5 13:36:32 2024 -0400

    use conditional mutations to remove hosting request (#4635)
---
 .../org/apache/accumulo/tserver/TabletServer.java    | 20 +++++++++++++++++---
 .../test/functional/OnDemandTabletUnloadingIT.java   |  3 +++
 2 files changed, 20 insertions(+), 3 deletions(-)

diff --git 
a/server/tserver/src/main/java/org/apache/accumulo/tserver/TabletServer.java 
b/server/tserver/src/main/java/org/apache/accumulo/tserver/TabletServer.java
index 8aa8f65f4b..bab4c589a6 100644
--- a/server/tserver/src/main/java/org/apache/accumulo/tserver/TabletServer.java
+++ b/server/tserver/src/main/java/org/apache/accumulo/tserver/TabletServer.java
@@ -41,6 +41,7 @@ import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Optional;
 import java.util.Set;
 import java.util.SortedMap;
 import java.util.SortedSet;
@@ -87,7 +88,7 @@ import org.apache.accumulo.core.manager.thrift.TableInfo;
 import org.apache.accumulo.core.manager.thrift.TabletServerStatus;
 import org.apache.accumulo.core.metadata.AccumuloTable;
 import org.apache.accumulo.core.metadata.TServerInstance;
-import org.apache.accumulo.core.metadata.schema.Ample.TabletsMutator;
+import org.apache.accumulo.core.metadata.schema.Ample;
 import org.apache.accumulo.core.metadata.schema.TabletMetadata;
 import org.apache.accumulo.core.metrics.MetricsInfo;
 import org.apache.accumulo.core.rpc.ThriftUtil;
@@ -1180,6 +1181,9 @@ public class TabletServer extends AbstractServer 
implements TabletHostingServer
         return;
       }
     });
+
+    var myLocation = TabletMetadata.Location.current(getTabletSession());
+
     tableIds.forEach(tid -> {
       Map<KeyExtent,
           Long> subset = sortedOnDemandExtents.entrySet().stream()
@@ -1191,10 +1195,20 @@ public class TabletServer extends AbstractServer 
implements TabletHostingServer
       UnloaderParams params = new UnloaderParamsImpl(tid, new 
ServiceEnvironmentImpl(context),
           subset, onDemandTabletsToUnload);
       unloaders.get(tid).evaluate(params);
-      try (TabletsMutator tm = getContext().getAmple().mutateTablets()) {
+      try (var tabletsMutator = 
getContext().getAmple().conditionallyMutateTablets()) {
         onDemandTabletsToUnload.forEach(ke -> {
           log.debug("Unloading on-demand tablet: {} for table: {}", ke, tid);
-          tm.mutateTablet(ke).deleteHostingRequested().mutate();
+          
tabletsMutator.mutateTablet(ke).requireLocation(myLocation).deleteHostingRequested()
+              .submit(tm -> !tm.getHostingRequested());
+        });
+
+        tabletsMutator.process().forEach((extent, result) -> {
+          if (result.getStatus() != Ample.ConditionalResult.Status.ACCEPTED) {
+            var loc = 
Optional.ofNullable(result.readMetadata()).map(TabletMetadata::getLocation)
+                .orElse(null);
+            log.debug("Failed to clear hosting request marker for {} location 
in metadata:{}",
+                extent, loc);
+          }
         });
       }
     });
diff --git 
a/test/src/main/java/org/apache/accumulo/test/functional/OnDemandTabletUnloadingIT.java
 
b/test/src/main/java/org/apache/accumulo/test/functional/OnDemandTabletUnloadingIT.java
index 1c9de1da24..27bf68a5d6 100644
--- 
a/test/src/main/java/org/apache/accumulo/test/functional/OnDemandTabletUnloadingIT.java
+++ 
b/test/src/main/java/org/apache/accumulo/test/functional/OnDemandTabletUnloadingIT.java
@@ -267,6 +267,9 @@ public class OnDemandTabletUnloadingIT extends 
SharedMiniClusterBase {
         scanner.setConsistencyLevel(ScannerBase.ConsistencyLevel.IMMEDIATE);
         assertEquals(100, scanner.stream().count());
       }
+
+      // delete table to unhost any tablets so they do not show up in counts 
for the next test
+      c.tableOperations().delete(tableName);
     }
   }
 }