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 usingMULTIandEXECexecute 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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