rueidis
A Fast Golang Redis RESP3 client that does auto pipelining and supports client side caching.
Features
- auto pipeline for non-blocking redis commands
- connection pooling for blocking redis commands
- opt-in client side caching
- redis cluster, pub/sub, streams, TLS, RedisJSON, RedisBloom, RediSearch, RedisGraph, RedisTimeseries
- IDE friendly redis command builder
- Hash/RedisJSON Object Mapping with client side caching and optimistic locking
- OpenTelemetry tracing and metrics
Requirement
- Currently, only supports redis >= 6.x
Getting Started
package main
import (
"context"
"github.com/rueian/rueidis"
)
func main() {
c, _ := rueidis.NewClient(rueidis.ClientOption{
InitAddress: []string{"127.0.0.1:6379"},
})
defer c.Close()
ctx := context.Background()
// SET key val NX
c.Do(ctx, c.B().Set().Key("key").Value("val").Nx().Build()).Error()
// GET key
c.Do(ctx, c.B().Get().Key("key").Build()).ToString()
}
Auto Pipeline
All non-blocking commands sending to a single redis instance are automatically pipelined through one tcp connection, which reduces the overall round trip costs, and gets higher throughput.
Benchmark comparison with go-redis v8.11.4
Rueidis has higher throughput than go-redis v8.11.4 across 1, 8, and 64 parallelism settings.
It is even able to achieve ~14x throughput over go-redis in a local benchmark. (see parallelism(64)-key(16)-value(64)-10)
Single Client
Cluster Client
Benchmark source code: https://github.com/rueian/rueidis-benchmark
Client Side Caching
The Opt-In mode of server-assisted client side caching is always enabled, and can be used by calling DoCache() with an explicit client side TTL.
c.DoCache(ctx, c.B().Hmget().Key("myhash").Field("1", "2").Cache(), time.Minute).ToArray()
An explicit client side TTL is required because redis server may not send invalidation message in time when a key is expired on the server. Please follow #6833 and #6867
Although an explicit client side TTL is required, the DoCache() still sends a PTTL command to server and make sure that the client side TTL is not longer than the TTL on server side.
Users can use IsCacheHit() to verify that if the response came from the client side memory.
c.DoCache(ctx, c.B().Hmget().Key("myhash").Field("1", "2").Cache(), time.Minute).IsCacheHit() == true
If the OpenTelemetry is enabled by the rueidisotel.WithClient(client), then there are also two metrics instrumented:
- rueidis_do_cache_miss
- rueidis_do_cache_hits
Benchmark
Benchmark source code: https://github.com/rueian/rueidis-benchmark
Supported Commands for Client Side Caching
- bitcount
- bitfieldro
- bitpos
- expiretime
- geodist
- geohash
- geopos
- georadiusro
- georadiusbymemberro
- geosearch
- get
- getbit
- getrange
- hexists
- hget
- hgetall
- hkeys
- hlen
- hmget
- hstrlen
- hvals
- lindex
- llen
- lpos
- lrange
- pexpiretime
- pttl
- scard
- sismember
- smembers
- smismember
- sortro
- strlen
- ttl
- type
- zcard
- zcount
- zlexcount
- zmscore
- zrange
- zrangebylex
- zrangebyscore
- zrank
- zrevrange
- zrevrangebylex
- zrevrangebyscore
- zrevrank
- zscore
- jsonget
- jsonstrlen
- jsonarrindex
- jsonarrlen
- jsonobjkeys
- jsonobjlen
- jsontype
- jsonresp
- bfexists
- bfinfo
- cfexists
- cfcount
- cfinfo
- cmsquery
- cmsinfo
- topkquery
- topklist
- topkinfo
Blocking Commands
The following blocking commands use another connection pool and will not share the same connection with non-blocking commands and thus will not cause the pipeline to be blocked:
- xread with block
- xreadgroup with block
- blpop
- brpop
- brpoplpush
- blmove
- blmpop
- bzpopmin
- bzpopmax
- bzmpop
- clientpause
- migrate
- wait
Pub/Sub
To receive messages from channels, the message handler should be registered when creating the redis connection:
c, _ := rueidis.NewClient(rueidis.ClientOption{
InitAddress: []string{"127.0.0.1:6379"},
PubSubOption: rueidis.NewPubSubOption(func(prev error, client rueidis.DedicatedClient) {
// Subscribe channels in this PubSubSetup hook for auto reconnecting after disconnected.
// The "prev" err is previous disconnect error.
err := client.Do(ctx, client.B().Subscribe().Channel("my_channel").Build()).Error()
}, rueidis.PubSubHandler{
OnMessage: func(channel, message string) {
// handle the message
},
},
})
CAS Pattern
To do a CAS operation (WATCH + MULTI + EXEC), a dedicated connection should be used, because there should be no unintentional write commands between WATCH and EXEC. Otherwise, the EXEC may not fail as expected.
The dedicated connection shares the same connection pool with blocking commands.
c.Dedicated(func(client client.DedicatedClient) error {
// watch keys first
client.Do(ctx, client.B().Watch().Key("k1", "k2").Build())
// perform read here
client.Do(ctx, client.B().Mget().Key("k1", "k2").Build())
// perform write with MULTI EXEC
client.DoMulti(
ctx,
client.B().Multi().Build(),
client.B().Set().Key("k1").Value("1").Build(),
client.B().Set().Key("k2").Value("2").Build(),
client.B().Exec().Build(),
)
return nil
})
However, occupying a connection is not good in terms of throughput. It is better to use Lua script to perform optimistic locking instead.
Lua Script
The NewLuaScript or NewLuaScriptReadOnly will create a script which is safe for concurrent usage.
When calling the script.Exec, it will try sending EVALSHA to the client and if the server returns NOSCRIPT, it will send EVAL to try again.
script := rueidis.NewLuaScript("return {KEYS[1],KEYS[2],ARGV[1],ARGV[2]}")
// the script.Exec is safe for concurrent call
list, err := script.Exec(ctx, client, []string{"k1", "k2"}, []string{"a1", "a2"}).ToArray()
Redis Cluster and Single Redis
To connect to a redis cluster, the NewClient should be used:
c, _ := rueidis.NewClient(rueidis.ClientOption{
InitAddress: []string{"127.0.0.1:7001", "127.0.0.1:7002", "127.0.0.1:7003"},
ShuffleInit: true,
})
To connect to a single redis node, still use the NewClient with one InitAddress
Command Builder
Redis commands are very complex and their formats are very different from each other.
This library provides a type safe command builder within client.B() that can be used as an entrypoint to construct a redis command. Once the command is completed, call the Build() or Cache() to get the actual command. And then pass it to either Client.Do() or Client.DoCache().
c.Do(ctx, c.B().Set().Key("mykey").Value("myval").Ex(10).Nx().Build())
Once the command is passed to the Client.Do(), Client.DoCache(), the command will be recycled and should not be reused.
The ClusterClient.B() also checks if the command contains multiple keys belongs to different slots. If it does, then panic.
Object Mapping
The NewHashRepository and NewJSONRepository creates an OM repository backed by redis hash or RedisJSON.
package main
import (
"context"
"fmt"
"time"
"github.com/rueian/rueidis"
"github.com/rueian/rueidis/om"
)
type Example struct {
Key string `json:"key" redis:",key"` // the redis:",key" is required to indicate which field is the ULID key
Ver int64 `json:"ver" redis:",ver"` // the redis:",ver" is required to do optimistic locking to prevent lost update
Str string `json:"myStr"` // both NewHashRepository and NewJSONRepository use json tag as field name
}
func main() {
ctx := context.Background()
c, _ := rueidis.NewClient(rueidis.ClientOption{InitAddress: []string{"127.0.0.1:6379"}})
// create the repo with NewHashRepository or NewJSONRepository
repo := om.NewHashRepository("my_prefix", Example{}, c)
exp := repo.NewEntity().(*Example)
exp.Str = "mystr"
fmt.Println(exp.Key) // output 01FNH4FCXV9JTB9WTVFAAKGSYB
repo.Save(ctx, exp) // success
// lookup "my_prefix:01FNH4FCXV9JTB9WTVFAAKGSYB" through client side caching
cache, _ := repo.FetchCache(ctx, exp.Key, time.Second*5)
exp2 := cache.(*Example)
fmt.Println(exp2.Str) // output "mystr", which equals to exp.Str
exp2.Ver = 0 // if someone changes the version during your GET then SET operation,
repo.Save(ctx, exp2) // the save will fail with ErrVersionMismatch.
}
Object Mapping + RediSearch
If you have RediSearch, you can create and search the repository against the index.
if _, ok := repo.(*om.HashRepository); ok {
repo.CreateIndex(ctx, func(schema om.FtCreateSchema) om.Completed {
return schema.FieldName("myStr").Text().Build() // Note that the Example.Str field is mapped to myStr on redis by its json tag
})
}
if _, ok := repo.(*om.JSONRepository); ok {
repo.CreateIndex(ctx, func(schema om.FtCreateSchema) om.Completed {
return schema.FieldName("$.myStr").Text().Build() // the field name of json index should be a json path syntax
})
}
exp := repo.NewEntity().(*Example)
exp.Str = "foo"
repo.Save(ctx, exp)
n, records, _ := repo.Search(ctx, func(search om.FtSearchIndex) om.Completed {
return search.Query("foo").Build() // you have full query capability by building the command from om.FtSearchIndex
})
fmt.Println("total", n) // n is total number of results matched in redis, which is >= len(records)
for _, v := range records.([]*Example) {
fmt.Println(v.Str) // print "foo"
}
Object Mapping Limitation
NewHashRepository only accepts these field types:
string,*stringint64,*int64bool,*bool[]byte
Field projection by RediSearch is not supported.
OpenTelemetry Tracing
Use rueidisotel.WithClient to create a client with OpenTelemetry Tracing enabled.
package main
import (
"github.com/rueian/rueidis"
"github.com/rueian/rueidis/rueidisotel"
)
func main() {
client, _ := rueidis.NewClient(rueidis.ClientOption{InitAddress: []string{"127.0.0.1:6379"}})
client = rueidisotel.WithClient(client)
defer client.Close()
}
Command Response Cheatsheet
It is hard to remember what message type is returned from redis and which parsing method should be used with. So, here is some common examples:
// GET
client.Do(ctx, client.B().Get().Key("k").Build()).ToString()
client.Do(ctx, client.B().Get().Key("k").Build()).AsInt64()
// MGET
client.Do(ctx, client.B().Mget().Key("k1", "k2").Build()).ToArray()
// SET
client.Do(ctx, client.B().Set().Key("k").Value("v").Build()).Error()
// INCR
client.Do(ctx, client.B().Incr().Key("k").Build()).ToInt64()
// HGET
client.Do(ctx, client.B().Hget().Key("k").Field("f").Build()).ToString()
// HMGET
client.Do(ctx, client.B().Hmget().Key("h").Field("a", "b").Build()).ToArray()
// HGETALL
client.Do(ctx, client.B().Hgetall().Key("h").Build()).AsStrMap()
// ZRANGE
client.Do(ctx, client.B().Zrange().Key("k").Min("1").Max("2").Build()).AsStrSlice()
// ZRANK
client.Do(ctx, client.B().Zrank().Key("k").Member("m").Build()).ToInt64()
// ZSCORE
client.Do(ctx, client.B().Zscore().Key("k").Member("m").Build()).ToFloat64()
// SCARD
client.Do(ctx, client.B().Scard().Key("k").Build()).ToInt64()
// SMEMBERS
client.Do(ctx, client.B().Smembers().Key("k").Build()).AsStrSlice()
// LINDEX
client.Do(ctx, client.B().Lindex().Key("k").Index(0).Build()).ToString()
// LPOP
client.Do(ctx, client.B().Lpop().Key("k").Build()).ToString()
client.Do(ctx, client.B().Lpop().Key("k").Count(2).Build()).AsStrSlice()
Not Yet Implement
The following subjects are not yet implemented.
- go-redis like api layer
- RESP2
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