Unlock 16 Powerful Redis Use Cases to Supercharge Your Backend

1. Caching

Use the String type for hot data such as reports or popular content; object caching and full‑page caching can dramatically improve access speed.

2. Distributed Data Sharing

Because Redis is a standalone distributed service, String keys can be shared across multiple applications, e.g., for distributed sessions.

<dependency>
  <groupId>org.springframework.session</groupId>
  <artifactId>spring-session-data-redis</artifactId>
</dependency>

3. Distributed Lock

Implement a lock with SETNX (set if not exists); if the lock is acquired, set an expiration to avoid deadlocks.

public static boolean getLock(String key) {
    Long flag = jedis.setnx(key, "1");
    if (flag == 1) {
        jedis.expire(key, 10);
    }
    return flag == 1;
}
public static void releaseLock(String key) {
    jedis.del(key);
}

4. Global ID

Use the int type with INCRBY to generate atomic sequential IDs, e.g., INCRBY userid 1000, useful for sharding scenarios.

5. Counter

Simple integer counters via INCR can track reads, likes, etc., with eventual synchronization to a relational database.

6. Rate Limiting

Store a counter keyed by IP or other identifier; each request increments the counter, and exceeding a threshold returns false.

7. Bitmaps

Redis String bitmaps enable space‑efficient statistics; BITCOUNT counts set bits.

set k1 a
setbit k1 6 1
setbit k1 7 0
get k1

Bitwise operations ( BITOP AND/OR/XOR/NOT) allow complex analytics such as finding users online for seven consecutive days.

BITOP AND destkey key1 key2 ...
BITOP OR destkey key1 key2 ...
BITOP XOR destkey key1 key2 ...
BITOP NOT destkey key

8. Shopping Cart

Model a cart with a hash : key = userId, field = productId, value = quantity. Operations: HINCRBY to add/subtract, HDEL to remove, HGETALL to list, HLEN for count.

9. Timeline

Use a list (double‑ended queue) to store ordered events; insertions keep chronological order.

10. Message Queue

Redis list provides blocking pop commands BLPOP and BRPOP with timeout, mirroring Java's blocking queue semantics (FIFO).

11. Lottery

Random selection via SPOP on a set returns a random member.

12. Likes / Check‑ins / Punch‑in

Maintain a set per post, e.g., like:t1001, where SADD adds a user, SREM removes, SISMEMBER checks, SCARD counts.

13. Product Tags

Store tags in a set like tags:i5001; each tag string is added with SADD.

14. Product Filtering

Combine sets using SDIFF (difference), SINTER (intersection), and SUNION (union) to filter products by brand, OS, screen size, etc.

sdiff set1 set2
sinter set1 set2
sunion set1 set2

15. Follow / Recommendation Model

Represent follows and fans with sets: sadd 1:follow 2, sadd 2:fans 1. Mutual follows are intersections; potential acquaintances are derived via set differences.

sadd 1:follow 2
sadd 2:fans 1
sadd 1:fans 2
sadd 2:follow 1
sinter 1:follow 2:fans
sdiff 2:follow 1:follow
sdiff 1:follow 2:follow

16. Ranking

Increment a sorted‑set score with ZINCRBY (e.g., zincrby hotNews:20190926 1 n6001) and retrieve top items via ZREVRANGE with scores.

zincrby hotNews:20190926 1 n6001
zrevrange hotNews:20190926 0 15 withscores