What are redis locks?

Redis provides 6 lock types: SETNX, REDIS, RedLock, Lua script, Watch MULTI EXEC and reentrant locks for coordinated access to shared resources in a distributed environment.

Redis lock type

Redis provides the following types of locks:

1 . SETNX

• Atomicly sets a key and its value.
• If the key does not exist, the setting is successful and 1 is returned; otherwise, 0 is returned.

2. REDIS (Distributed Lock Framework)

• A distributed lock framework based on Redis.
• Provides high availability and fault tolerance and can be used to coordinate locks across multiple server instances.

3. RedLock

• A distributed coordinated lock algorithm based on Redis.
• Use multiple Redis instances to improve availability and fault tolerance.

4. Lua script

• Allows the use of Lua scripts to execute multiple Redis commands atomically.
• Can be used to create custom lock mechanisms.

5. Watch MULTI EXEC

• Monitor key changes by using WATCH, and using MULTI and EXEC execute commands atomically and can implement simple locks.

6. Reentrant Lock

• Allows a thread to acquire the same lock multiple times.
• Achieved by maintaining a counter that records the number of times the thread currently holds the lock.

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