fail the update when blob version is different from transition plan v…

…ersion
Netflix · Nov 30, 2023 · 3df6e33 · 3df6e33
1 parent e7ce7db
commit 3df6e33
Show file tree

Hide file tree

Showing 3 changed files with 61 additions and 1 deletion.
diff --git a/hollow/src/main/java/com/netflix/hollow/api/client/HollowDataHolder.java b/hollow/src/main/java/com/netflix/hollow/api/client/HollowDataHolder.java
@@ -19,6 +19,7 @@
 import com.netflix.hollow.api.consumer.HollowConsumer;
 import com.netflix.hollow.api.consumer.HollowConsumer.TransitionAwareRefreshListener;
 import com.netflix.hollow.api.custom.HollowAPI;
+import com.netflix.hollow.api.error.VersionMismatchException;
 import com.netflix.hollow.core.HollowConstants;
 import com.netflix.hollow.core.memory.MemoryMode;
 import com.netflix.hollow.core.read.HollowBlobInput;
@@ -33,8 +34,12 @@
 import com.netflix.hollow.tools.history.HollowHistoricalStateDataAccess;
 import java.io.IOException;
 import java.lang.ref.WeakReference;
+import java.util.Optional;
+import java.util.OptionalLong;
 import java.util.logging.Logger;
 
+import static com.netflix.hollow.core.HollowStateEngine.HEADER_TAG_PRODUCER_TO_VERSION;
+
 /**
  * A class comprising much of the internal state of a {@link HollowConsumer}.  Not intended for external consumption.
  */
@@ -177,8 +182,16 @@ private void applyStateEngineTransition(HollowBlobInput in, OptionalBlobPartInpu
             reader.applyDelta(in, optionalPartIn);
         }
 
-        setVersion(transition.getToVersion());
+        long expectedToVersion = transition.getToVersion();
+        String actualToVersionStr = stateEngine.getHeaderTag(HEADER_TAG_PRODUCER_TO_VERSION);
+        if (actualToVersionStr != null) {
+            long actualToVersion = Long.parseLong(actualToVersionStr);
+            if (actualToVersion != expectedToVersion) {
+                throw new VersionMismatchException(expectedToVersion, actualToVersion);
+            }
+        }
 
+        setVersion(transition.getToVersion());
         for(HollowConsumer.RefreshListener refreshListener : refreshListeners)
             refreshListener.blobLoaded(transition);
     }

diff --git a/hollow/src/main/java/com/netflix/hollow/api/error/VersionMismatchException.java b/hollow/src/main/java/com/netflix/hollow/api/error/VersionMismatchException.java
@@ -0,0 +1,21 @@
+package com.netflix.hollow.api.error;
+
+public class VersionMismatchException extends HollowException {
+    private final long expectedVersion;
+
+    private final long actualVersion;
+
+    public VersionMismatchException(long expectedVersion, long actualVersion) {
+        super("toVersion in blob didn't match toVersion seen in metadata; actualToVersion=" + actualVersion + ", expectedToVersion=" + expectedVersion);
+        this.expectedVersion = expectedVersion;
+        this.actualVersion = actualVersion;
+    }
+
+    public long getExpectedVersion() {
+        return expectedVersion;
+    }
+
+    public long getActualVersion() {
+        return actualVersion;
+    }
+}
diff --git a/hollow/src/test/java/com/netflix/hollow/api/client/HollowClientUpdaterTest.java b/hollow/src/test/java/com/netflix/hollow/api/client/HollowClientUpdaterTest.java
@@ -18,6 +18,7 @@
 
 import static com.netflix.hollow.core.HollowConstants.VERSION_LATEST;
 import static com.netflix.hollow.core.HollowConstants.VERSION_NONE;
+import static com.netflix.hollow.core.HollowStateEngine.HEADER_TAG_PRODUCER_TO_VERSION;
 import static com.netflix.hollow.core.HollowStateEngine.HEADER_TAG_SCHEMA_HASH;
 import static java.util.Collections.emptyList;
 import static org.junit.Assert.assertEquals;
@@ -30,6 +31,7 @@
 
 import com.netflix.hollow.api.consumer.HollowConsumer;
 import com.netflix.hollow.api.custom.HollowAPI;
+import com.netflix.hollow.api.error.VersionMismatchException;
 import com.netflix.hollow.api.metrics.HollowConsumerMetrics;
 import com.netflix.hollow.core.HollowStateEngine;
 import com.netflix.hollow.core.memory.MemoryMode;
@@ -46,6 +48,7 @@
 import com.netflix.hollow.test.consumer.TestHollowConsumer;
 import java.io.ByteArrayInputStream;
 import java.io.ByteArrayOutputStream;
+import java.io.IOException;
 import java.util.HashMap;
 import java.util.Map;
 import java.util.Optional;
@@ -55,6 +58,8 @@
 import java.util.logging.LogManager;
 import java.util.logging.LogRecord;
 import java.util.logging.Logger;
+
+import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Rule;
 import org.junit.Test;
@@ -98,6 +103,27 @@ public void testUpdateTo_noVersions() throws Throwable {
         assertTrue("Should still have no types", readStateEngine.getAllTypes().isEmpty());
     }
 
+    @Test
+    public void testUpdateTo_updateToLatestButBlobOnDifferentVersion() throws Throwable {
+        expectedException.expect(VersionMismatchException.class);
+        expectedException.expectMessage("Could not create an update plan, because no existing versions could be retrieved.");
+        long updateToVersion = 1234;
+        long blobToVersion = 1235; //this needs to be different from updateToVersion
+        HollowWriteStateEngine writeStateEngine = new HollowWriteStateEngine();
+        writeStateEngine.addHeaderTag(HEADER_TAG_PRODUCER_TO_VERSION, String.valueOf(blobToVersion));
+        ByteArrayOutputStream os = new ByteArrayOutputStream();
+        new HollowBlobWriter(writeStateEngine).writeSnapshot(os);
+        ByteArrayInputStream is = new ByteArrayInputStream(os.toByteArray());
+        HollowConsumer.Blob blob = mock(HollowConsumer.Blob.class);
+        when(blob.isSnapshot())
+                .thenReturn(true);
+        when(blob.getInputStream())
+                .thenReturn(is);
+        when(retriever.retrieveSnapshotBlob(anyLong()))
+                .thenReturn(blob);
+        subject.updateTo(updateToVersion);
+    }
+
     @Rule
     public ExpectedException expectedException = ExpectedException.none();