The XADD
command in Redis is used when working with streams. It appends a new entry to a stream. Common use cases include:
Let's consider a scenario where we are using Redis for logging user activities. In this case, each activity will be a new entry in the stream.
We will use the go-redis
package for our examples.
package main import ( "fmt" "github.com/go-redis/redis/v8" "context" ) func main() { rdb := redis.NewClient(&redis.Options{ Addr: "localhost:6379", Password: "", DB: 0, }) ctx := context.Background() err := rdb.XAdd(ctx, &redis.XAddArgs{ Stream: "userActivity", Values: map[string]interface{}{"user": "john", "activity": "login"}, }).Err() if err != nil { panic(err) } fmt.Println("User activity added") }
This simple program connects to Redis and adds an activity record to the 'userActivity' stream.
Use meaningful and descriptive names for your streams. This makes it easier to identify their contents.
When adding a large number of entries to a stream, you may want to limit its length to prevent it from consuming too much memory. You can do this using the MAXLEN
argument in the XADD
command.
Not handling potential errors when interacting with Redis can lead to silent failures. Always check for an error after calling the XAdd
function.
While adding entries to a stream, make sure the fields and values correctly match up in your data structure. Mismatched or missing field-value pairs may cause issues.
Q: What data structure does Redis XADD use? A: It uses the Stream data structure.
Q: Is there a limit on the number of entries in a stream?
A: By default, there isn't. However, you can set one using the MAXLEN
argument in XADD
.
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement.