Merge pull request #471 from citusdata/rename_copy_transaction_manager

Rename citus.copy_transaction_manager to citus.multi_shard_commit_protocol

src/backend/distributed/commands/multi_copy.c

@@ -25,7 +25,7 @@
  * hash or range-partitioned tables, this can cause a problem when some of the
  * transactions fail to commit while others have succeeded. To ensure no data
  * is lost, COPY can use two-phase commit, by increasing max_prepared_transactions
- * on the worker and setting citus.copy_transaction_manager to '2pc'. The default
+ * on the worker and setting citus.multi_shard_commit_protocol to '2pc'. The default
  * is '1pc'. This is not a problem for append-partitioned tables because new
  * shards are created and in the case of failure, metadata changes are rolled
  * back on the master node.
@@ -125,9 +125,6 @@
 #define INITIAL_CONNECTION_CACHE_SIZE 1001
 
 
-/* the transaction manager to use for COPY commands */
-int CopyTransactionManager = TRANSACTION_MANAGER_1PC;
-
 /* constant used in binary protocol */
 static const char BinarySignature[11] = "PGCOPY\n\377\r\n\0";
 
@@ -449,7 +446,7 @@ CopyToExistingShards(CopyStmt *copyStatement, char *completionTag)
 		/* close the COPY input on all shard placements */
 		EndRemoteCopy(connectionList, true);
 
-		if (CopyTransactionManager == TRANSACTION_MANAGER_2PC)
+		if (MultiShardCommitProtocol == COMMIT_PROTOCOL_2PC)
 		{
 			PrepareRemoteTransactions(connectionList);
 		}

src/backend/distributed/shared_library_init.c

@@ -68,9 +68,9 @@ static const struct config_enum_entry shard_placement_policy_options[] = {
 	{ NULL, 0, false }
 };
 
-static const struct config_enum_entry transaction_manager_options[] = {
-	{ "1pc", TRANSACTION_MANAGER_1PC, false },
-	{ "2pc", TRANSACTION_MANAGER_2PC, false },
+static const struct config_enum_entry multi_shard_commit_protocol_options[] = {
+	{ "1pc", COMMIT_PROTOCOL_1PC, false },
+	{ "2pc", COMMIT_PROTOCOL_2PC, false },
 	{ NULL, 0, false }
 };
 
@@ -448,16 +448,17 @@ RegisterCitusConfigVariables(void)
 		NULL, NULL, NULL);
 
 	DefineCustomEnumVariable(
-		"citus.copy_transaction_manager",
-		gettext_noop("Sets the transaction manager for COPY into distributed tables."),
-		gettext_noop("When a failure occurs during when copying into a distributed "
-					 "table, 2PC is required to ensure data is never lost. Change "
-					 "this setting to '2pc' from its default '1pc' to enable 2PC."
-					 "You must also set max_prepared_transactions on the worker "
-					 "nodes. Recovery from failed 2PCs is currently manual."),
-		&CopyTransactionManager,
-		TRANSACTION_MANAGER_1PC,
-		transaction_manager_options,
+		"citus.multi_shard_commit_protocol",
+		gettext_noop("Sets the commit protocol for commands modifying multiple shards."),
+		gettext_noop("When a failure occurs during commands that modify multiple "
+					 "shards (currently, only COPY on distributed tables modifies more "
+					 "than one shard), two-phase commit is required to ensure data is "
+					 "never lost. Change this setting to '2pc' from its default '1pc' to "
+					 "enable 2 PC. You must also set max_prepared_transactions on the "
+					 "worker nodes. Recovery from failed 2PCs is currently manual."),
+		&MultiShardCommitProtocol,
+		COMMIT_PROTOCOL_1PC,
+		multi_shard_commit_protocol_options,
 		PGC_USERSET,
 		0,
 		NULL, NULL, NULL);

src/backend/distributed/utils/multi_transaction.c

@@ -28,6 +28,10 @@ static uint32 DistributedTransactionId = 0;
 static StringInfo BuildTransactionName(int connectionId);
 
 
+/* the commit protocol to use for COPY commands */
+int MultiShardCommitProtocol = COMMIT_PROTOCOL_1PC;
+
+
 /*
  * InitializeDistributedTransaction prepares the distributed transaction ID
  * used in transaction names.
@@ -41,7 +45,7 @@ InitializeDistributedTransaction(void)
 
 /*
  * PrepareRemoteTransactions prepares all transactions on connections in
- * connectionList for commit if the 2PC transaction manager is enabled.
+ * connectionList for commit if the 2PC commit protocol is enabled.
  * On failure, it reports an error and stops.
  */
 void

src/include/distributed/multi_copy.h

@@ -17,7 +17,7 @@
 
 
 /* config variable managed via guc.c */
-extern int CopyTransactionManager;
+extern int MultiShardCommitProtocol;
 
 
 /*

src/include/distributed/multi_transaction.h

@@ -18,12 +18,12 @@
 #include "nodes/pg_list.h"
 
 
-/* Enumeration that defines the different transaction managers available */
+/* Enumeration that defines the different commit protocols available */
 typedef enum
 {
-	TRANSACTION_MANAGER_1PC = 0,
-	TRANSACTION_MANAGER_2PC = 1
-} TransactionManagerType;
+	COMMIT_PROTOCOL_1PC = 0,
+	COMMIT_PROTOCOL_2PC = 1
+} CommitProtocolType;
 
 /* Enumeration that defines different remote transaction states */
 typedef enum
@@ -47,6 +47,10 @@ typedef struct TransactionConnection
 } TransactionConnection;
 
 
+/* config variable managed via guc.c */
+extern int MultiShardCommitProtocol;
+
+
 /* Functions declarations for transaction and connection management */
 extern void InitializeDistributedTransaction(void);
 extern void PrepareRemoteTransactions(List *connectionList);