Backport to branch(3) : Remove version from prepare-records condition in Consensus Commit (#2682)

Co-authored-by: Toshihiro Suzuki <[email protected]>

Author: feeblefakie

core/src/main/java/com/scalar/db/transaction/consensuscommit/PrepareMutationComposer.java

@@ -1,7 +1,6 @@
 package com.scalar.db.transaction.consensuscommit;
 
 import static com.scalar.db.transaction.consensuscommit.Attribute.ID;
-import static com.scalar.db.transaction.consensuscommit.Attribute.VERSION;
 import static com.scalar.db.transaction.consensuscommit.ConsensusCommitOperationAttributes.isInsertModeEnabled;
 import static com.scalar.db.transaction.consensuscommit.ConsensusCommitUtils.getNextTxVersion;
 
@@ -73,13 +72,10 @@ private void add(Put base, @Nullable TransactionResult result) throws ExecutionE
       if (result.isDeemedAsCommitted()) {
         // record is deemed-commit state
         putBuilder.condition(
-            ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText())
-                .and(ConditionBuilder.column(VERSION).isNullInt())
-                .build());
+            ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText()).build());
       } else {
         putBuilder.condition(
             ConditionBuilder.putIf(ConditionBuilder.column(ID).isEqualToText(result.getId()))
-                .and(ConditionBuilder.column(VERSION).isEqualToInt(version))
                 .build());
       }
     } else { // initial record or insert mode enabled
@@ -113,13 +109,10 @@ private void add(Delete base, @Nullable TransactionResult result) throws Executi
       // check if the record is not interrupted by other conflicting transactions
       if (result.isDeemedAsCommitted()) {
         putBuilder.condition(
-            ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText())
-                .and(ConditionBuilder.column(VERSION).isNullInt())
-                .build());
+            ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText()).build());
       } else {
         putBuilder.condition(
             ConditionBuilder.putIf(ConditionBuilder.column(ID).isEqualToText(result.getId()))
-                .and(ConditionBuilder.column(VERSION).isEqualToInt(version))
                 .build());
       }
     } else {

core/src/main/java/com/scalar/db/transaction/consensuscommit/Snapshot.java

@@ -497,9 +497,9 @@ void toSerializable(DistributedStorage storage)
       tasks.add(
           () -> {
             Optional<TransactionResult> originalResult = getSet.get(get);
-            // Only get tx_id and tx_version columns because we use only them to compare
+            // Only get the tx_id column because we use only them to compare
             get.clearProjections();
-            get.withProjection(Attribute.ID).withProjection(Attribute.VERSION);
+            get.withProjection(Attribute.ID);
 
             // Check if a read record is not changed
             Optional<TransactionResult> latestResult = storage.get(get).map(TransactionResult::new);
@@ -537,9 +537,9 @@ private void validateScanResults(
       throws ExecutionException, ValidationConflictException {
     Scanner scanner = null;
     try {
-      // Only get tx_id, tx_version and primary key columns because we use only them to compare
+      // Only get tx_id and primary key columns because we use only them to compare
       scan.clearProjections();
-      scan.withProjection(Attribute.ID).withProjection(Attribute.VERSION);
+      scan.withProjection(Attribute.ID);
       ScalarDbUtils.addProjectionsForKeys(scan, getTableMetadata(scan));
 
       if (scan.getLimit() == 0) {
@@ -653,8 +653,7 @@ private boolean isChanged(
   }
 
   private boolean isChanged(TransactionResult latestResult, TransactionResult result) {
-    return !Objects.equals(latestResult.getId(), result.getId())
-        || latestResult.getVersion() != result.getVersion();
+    return !Objects.equals(latestResult.getId(), result.getId());
   }
 
   private void throwExceptionDueToAntiDependency() throws ValidationConflictException {

core/src/test/java/com/scalar/db/transaction/consensuscommit/PrepareMutationComposerTest.java

@@ -2,9 +2,7 @@
 
 import static com.scalar.db.api.ConditionalExpression.Operator;
 import static com.scalar.db.transaction.consensuscommit.Attribute.ID;
-import static com.scalar.db.transaction.consensuscommit.Attribute.VERSION;
 import static com.scalar.db.transaction.consensuscommit.Attribute.toIdValue;
-import static com.scalar.db.transaction.consensuscommit.Attribute.toVersionValue;
 import static org.assertj.core.api.Assertions.assertThat;
 import static org.assertj.core.api.Assertions.assertThatThrownBy;
 import static org.mockito.ArgumentMatchers.any;
@@ -182,10 +180,7 @@ public void add_PutAndResultGiven_ShouldComposePutWithPutIfCondition() throws Ex
     // Assert
     Put actual = (Put) composer.get().get(0);
     put.withConsistency(Consistency.LINEARIZABLE);
-    put.withCondition(
-        new PutIf(
-            new ConditionalExpression(ID, toIdValue(ANY_ID_2), Operator.EQ),
-            new ConditionalExpression(VERSION, toVersionValue(2), Operator.EQ)));
+    put.withCondition(new PutIf(new ConditionalExpression(ID, toIdValue(ANY_ID_2), Operator.EQ)));
     put.withValue(Attribute.toPreparedAtValue(ANY_TIME_5));
     put.withValue(Attribute.toIdValue(ANY_ID_3));
     put.withValue(Attribute.toStateValue(TransactionState.PREPARED));
@@ -226,10 +221,7 @@ public void add_PutAndResultGiven_ShouldComposePutWithPutIfCondition() throws Ex
             .intValue(Attribute.BEFORE_STATE, null)
             .intValue(Attribute.BEFORE_VERSION, 0)
             .intValue(Attribute.BEFORE_PREFIX + ANY_NAME_3, ANY_INT_2)
-            .condition(
-                ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText())
-                    .and(ConditionBuilder.column(VERSION).isNullInt())
-                    .build())
+            .condition(ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText()).build())
             .build();
     assertThat(actual).isEqualTo(expected);
   }
@@ -321,9 +313,7 @@ public void add_DeleteAndResultGiven_ShouldComposePutWithPutIfCondition()
             .forTable(delete.forTable().get());
     expected.withConsistency(Consistency.LINEARIZABLE);
     expected.withCondition(
-        new PutIf(
-            new ConditionalExpression(ID, toIdValue(ANY_ID_2), Operator.EQ),
-            new ConditionalExpression(VERSION, toVersionValue(2), Operator.EQ)));
+        new PutIf(new ConditionalExpression(ID, toIdValue(ANY_ID_2), Operator.EQ)));
     expected.withValue(Attribute.toPreparedAtValue(ANY_TIME_5));
     expected.withValue(Attribute.toIdValue(ANY_ID_3));
     expected.withValue(Attribute.toStateValue(TransactionState.DELETED));
@@ -368,10 +358,7 @@ public void add_DeleteAndResultGiven_ShouldComposePutWithPutIfCondition()
             .intValue(Attribute.BEFORE_STATE, null)
             .intValue(Attribute.BEFORE_VERSION, 0)
             .intValue(Attribute.BEFORE_PREFIX + ANY_NAME_3, ANY_INT_2)
-            .condition(
-                ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText())
-                    .and(ConditionBuilder.column(VERSION).isNullInt())
-                    .build())
+            .condition(ConditionBuilder.putIf(ConditionBuilder.column(ID).isNullText()).build())
             .build();
     assertThat(actual).isEqualTo(expected);
   }