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Editor to share with you what are the commands for transaction operations in Redis. I hope you will gain something after reading this article. Let's discuss it together.

Command

Multi and exec

Command Lin

127.0.0.1 integer 6379 > multiOK127.0.0.1:6379 > incr totalQUEUED127.0.0.1:6379 > incr lenQUEUED127.0.0.1:6379 > exec1) (integer) 22) (integer) 2127.0.0.1 incr lenQUEUED127.0.0.1:6379 6379 > get total "2" 127.0.1 > get len "2"

Lettuce instance

@ Test public void testMultiExec () {RedisClient client = RedisClient.create ("redis://192.168.99.100:6379/0"); StatefulRedisConnection connection = client.connect (); RedisCommands syncCommands = connection.sync (); syncCommands.set ("hello", "1"); syncCommands.set ("world", "2"); syncCommands.multi (); syncCommands.incr ("hello") SyncCommands.incr ("world"); / / DefaultTransactionResult [wasRolledBack=false,result= [1,2,1,3,1]] TransactionResult transactionResult = syncCommands.exec (); System.out.println (transactionResult); System.out.println (syncCommands.get ("hello")); System.out.println (syncCommands.get ("world"));} partial execution

Command Lin

127.0.0.1 set 6379 > multiOK127.0.0.1:6379 > set a helloQUEUED127.0.0.1:6379 > set b worldQUEUED127.0.0.1:6379 > incr aQUEUED127.0.0.1:6379 > set c partQUEUED127.0.0.1:6379 > exec1) OK2) OK3) (error) ERR value is not an integer or out of range4) OK127.0.0.1:6379 > get a "hello" 127.0.0.1 Fran 6379 > get b "world" 127.0.0.1 Vol 6379 > get c "part"

Lettuce instance

@ Test public void testMultiExecError () {RedisClient client = RedisClient.create ("redis://192.168.99.100:6379/0"); StatefulRedisConnection connection = client.connect (); RedisCommands syncCommands = connection.sync (); syncCommands.multi (); syncCommands.set ("a", "hello"); syncCommands.set ("b", "world"); syncCommands.incr ("a") SyncCommands.set ("c", "part"); / / DefaultTransactionResult [wasRolledBack=false,result= [OK, OK, io.lettuce.core.RedisCommandExecutionException: ERR value is not an integer or out of range, OK, 1]] TransactionResult transactionResult = syncCommands.exec (); System.out.println (transactionResult); System.out.println (syncCommands.get ("a")); System.out.println (syncCommands.get ("b")) System.out.println (syncCommands.get ("c"));} multi and discard

Command Lin

127.0.0.1 incr sumQUEUED127.0.0.1:6379 6379 > set sum 1OK127.0.0.1:6379 > multiOK127.0.0.1:6379 > incr sumQUEUED127.0.0.1:6379 > discardOK127.0.0.1:6379 > get sum "1"

Lettuce instance

@ Test public void testMultiDiscard () {RedisClient client = RedisClient.create ("redis://192.168.99.100:6379/0"); StatefulRedisConnection connection = client.connect (); RedisCommands syncCommands = connection.sync (); syncCommands.incr ("key1"); syncCommands.multi (); syncCommands.incr ("key1") / / multi is required to execute discard. Successful return OK String result = syncCommands.discard (); System.out.println (result); System.out.println (syncCommands.get ("key1"));} check and set @ Test public void testWatch () {RedisClient client = RedisClient.create ("redis://192.168.99.100:6379/0"); StatefulRedisConnection connection = client.connect () RedisCommands syncCommands = connection.sync (); String key = "key"; syncCommands.watch (key); / / another connection StatefulRedisConnection conn2 = client.connect (); RedisCommands syncCommands2 = conn2.sync (); syncCommands2.set (key, "a"); syncCommands.multi (); syncCommands.append (key, "b") / / DefaultTransactionResult [wasRolledBack=true, responses=0] TransactionResult transactionResult = syncCommands.exec (); System.out.println (transactionResult); System.out.println (syncCommands.get (key));}

Reids provides multi exec/discard instructions, similar to open commit/rollback transaction, but exec does not roll when it encounters errors such as type operations, and the successful command is executed successfully, and the failed command is still failed.

Multi exec guarantees that as long as the exec command is executed successfully, a series of commands in the transaction can be executed. If the exec is not received by the server because of network problems, a series of commands in the transaction will not be executed.

Discard can only be used if multi is called, which clears the transaction queue for commands waiting to be executed.

Redis provides watch instruction, which can be used with multi exec and can implement optimistic locking mechanism similar to database. Once the key of watch is updated by other client, the whole exec operation fails.

After reading this article, I believe you have a certain understanding of "what are the commands for transaction operations in Redis". If you want to know more about it, you are welcome to follow the industry information channel. Thank you for reading!

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