Golang Redis Cache

• Redis config
• go-redis/cache
• Cache monitoring
• Monitoring Performance

Redis config

To start using Redis as a cache storage, use the following Redis config:

# Required
##########

# Set a memory usage limit to the specified amount of bytes.
# When the memory limit is reached Redis will try to remove keys
# according to the eviction policy selected (see maxmemory-policy).
maxmemory 100mb

# Optional
##########

# Evict any key using approximated LFU when maxmemory is reached.
maxmemory-policy allkeys-lfu

# Enable active memory defragmentation.
activedefrag yes

# Don't save data on the disk because we can afford to lose cached data.
save ""

go-redis/cache

go-redis/cache library implements a cache using Redis as a key/value storage. It uses MessagePack to marshal values.

You can install go-redis/cache with:

go get github.com/go-redis/cache/v8

go-redis/cache accepts an interface to communicate with Redis and thus supports all types of Redis clients that go-redis provides.

rdb := redis.NewClient(&redis.Options{
    Addr: "localhost:6379",
})

mycache := cache.New(&cache.Options{
    Redis: rdb,
})

obj := new(Object)
err := mycache.Once(&cache.Item{
    Key:   "mykey",
    Value: obj, // destination
    Do: func(*cache.Item) (interface{}, error) {
        return &Object{
            Str: "mystring",
            Num: 42,
        }, nil
    },
})
if err != nil {
    panic(err)
}

You can also use local in-process storage to cache the small subset of popular keys. go-redis/cache comes with TinyLFU, but you can use any other cache algorithm that implements the interface.

mycache := cache.New(&cache.Options{
    Redis:      rdb,
    // Cache 10k keys for 1 minute.
    LocalCache: cache.NewTinyLFU(10000, time.Minute),
})

Cache monitoring

If you are interested in monitoring cache hit rate, see the guide for Monitoring using OpenTelemetry Metrics.

Monitoring Performance

To monitor go-redis performance, you can use OpenTelemetry instrumentation that comes with go-redis and Uptrace.

Uptrace is an open source DataDog competitor that supports OpenTelemetry tracing, OpenTelemetry metrics, and logs. You can use it to monitor applications and set up automatic alerts to receive notifications via email, Slack, Telegram, and more.