fix(options): Add buffer sizes to failover. Update README (#3468)

* fix(options): Add buffer sizes to failover. Update README

* fix(spellcheck): add KiB in wordlist

* fix(comment): fix defaul value in comment

* fixes #3465

.github/wordlist.txt

@@ -74,4 +74,5 @@ Azure
 StreamingCredentialsProvider
 oauth
 entraid
-MiB
+MiB
+KiB

README.md

@@ -20,6 +20,7 @@ In `go-redis` we are aiming to support the last three releases of Redis. Current
 - [Redis 7.2](https://raw.githubusercontent.com/redis/redis/7.2/00-RELEASENOTES) - using Redis Stack 7.2 for modules support
 - [Redis 7.4](https://raw.githubusercontent.com/redis/redis/7.4/00-RELEASENOTES) - using Redis Stack 7.4 for modules support
 - [Redis 8.0](https://raw.githubusercontent.com/redis/redis/8.0/00-RELEASENOTES) - using Redis CE 8.0 where modules are included
+- [Redis 8.2](https://raw.githubusercontent.com/redis/redis/8.2/00-RELEASENOTES) - using Redis CE 8.2 where modules are included
 
 Although the `go.mod` states it requires at minimum `go 1.18`, our CI is configured to run the tests against all three
 versions of Redis and latest two versions of Go ([1.23](https://go.dev/doc/devel/release#go1.23.0),
@@ -77,6 +78,7 @@ key value NoSQL database that uses RocksDB as storage engine and is compatible w
 - [Redis Ring](https://redis.uptrace.dev/guide/ring.html).
 - [Redis Performance Monitoring](https://redis.uptrace.dev/guide/redis-performance-monitoring.html).
 - [Redis Probabilistic [RedisStack]](https://redis.io/docs/data-types/probabilistic/)
+- [Customizable read and write buffers size.](#custom-buffer-sizes)
 
 ## Installation
 
@@ -372,6 +374,21 @@ For example:
 ```
 You can find further details in the [query dialect documentation](https://redis.io/docs/latest/develop/interact/search-and-query/advanced-concepts/dialects/).
 
+#### Custom buffer sizes
+Prior to v9.12, the buffer size was the default go value of 4096 bytes. Starting from v9.12, 
+go-redis uses 256KiB read and write buffers by default for optimal performance.
+For high-throughput applications or large pipelines, you can customize buffer sizes:
+
+```go
+rdb := redis.NewClient(&redis.Options{
+    Addr:            "localhost:6379",
+    ReadBufferSize:  1024 * 1024, // 1MiB read buffer
+    WriteBufferSize: 1024 * 1024, // 1MiB write buffer
+})
+```
+
+**Important**: If you experience any issues with the default buffer sizes, please try setting them to the go default of 4096 bytes.
+
 ## Contributing
 We welcome contributions to the go-redis library! If you have a bug fix, feature request, or improvement, please open an issue or pull request on GitHub.
 We appreciate your help in making go-redis better for everyone.
@@ -412,6 +429,7 @@ vals, err := rdb.Eval(ctx, "return {KEYS[1],ARGV[1]}", []string{"key"}, "hello")
 res, err := rdb.Do(ctx, "set", "key", "value").Result()
 ```
 
+
 ## Run the test
 
 go-redis will start a redis-server and run the test cases.

internal/pool/buffer_size_test.go

@@ -34,12 +34,12 @@ var _ = Describe("Buffer Size Configuration", func() {
 		Expect(err).NotTo(HaveOccurred())
 		defer connPool.CloseConn(cn)
 
-		// Check that default buffer sizes are used (0.5MiB)
+		// Check that default buffer sizes are used (256KiB)
 		writerBufSize := getWriterBufSizeUnsafe(cn)
 		readerBufSize := getReaderBufSizeUnsafe(cn)
 
-		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
-		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
+		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
+		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
 	})
 
 	It("should use custom buffer sizes when specified", func() {
@@ -79,16 +79,16 @@ var _ = Describe("Buffer Size Configuration", func() {
 		Expect(err).NotTo(HaveOccurred())
 		defer connPool.CloseConn(cn)
 
-		// Check that default buffer sizes are used (0.5MiB)
+		// Check that default buffer sizes are used (256KiB)
 		writerBufSize := getWriterBufSizeUnsafe(cn)
 		readerBufSize := getReaderBufSizeUnsafe(cn)
 
-		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
-		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
+		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
+		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
 	})
 
-	It("should use 0.5MiB default buffer sizes for standalone NewConn", func() {
-		// Test that NewConn (without pool) also uses 0.5MiB defaults
+	It("should use 256KiB default buffer sizes for standalone NewConn", func() {
+		// Test that NewConn (without pool) also uses 256KiB buffers
 		netConn := newDummyConn()
 		cn := pool.NewConn(netConn)
 		defer cn.Close()
@@ -96,11 +96,11 @@ var _ = Describe("Buffer Size Configuration", func() {
 		writerBufSize := getWriterBufSizeUnsafe(cn)
 		readerBufSize := getReaderBufSizeUnsafe(cn)
 
-		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
-		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
+		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
+		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
 	})
 
-	It("should use 0.5MiB defaults even when pool is created directly without buffer sizes", func() {
+	It("should use 256KiB defaults even when pool is created directly without buffer sizes", func() {
 		// Test the scenario where someone creates a pool directly (like in tests)
 		// without setting ReadBufferSize and WriteBufferSize
 		connPool = pool.NewConnPool(&pool.Options{
@@ -114,12 +114,12 @@ var _ = Describe("Buffer Size Configuration", func() {
 		Expect(err).NotTo(HaveOccurred())
 		defer connPool.CloseConn(cn)
 
-		// Should still get 0.5MiB defaults because NewConnPool sets them
+		// Should still get 256KiB defaults because NewConnPool sets them
 		writerBufSize := getWriterBufSizeUnsafe(cn)
 		readerBufSize := getReaderBufSizeUnsafe(cn)
 
-		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
-		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 0.5MiB buffer size
+		Expect(writerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
+		Expect(readerBufSize).To(Equal(proto.DefaultBufferSize)) // Default 256KiB buffer size
 	})
 })
 

internal/proto/reader.go

@@ -12,8 +12,8 @@ import (
 	"github.com/redis/go-redis/v9/internal/util"
 )
 
-// DefaultBufferSize is the default size for read/write buffers (0.5MiB)
-const DefaultBufferSize = 512 * 1024
+// DefaultBufferSize is the default size for read/write buffers (256 KiB).
+const DefaultBufferSize = 256 * 1024
 
 // redis resp protocol data type.
 const (

options.go

@@ -135,14 +135,14 @@ type Options struct {
 	// Larger buffers can improve performance for commands that return large responses.
 	// Smaller buffers can improve memory usage for larger pools.
 	//
-	// default: 0.5MiB (524288 bytes)
+	// default: 256KiB (262144 bytes)
 	ReadBufferSize int
 
 	// WriteBufferSize is the size of the bufio.Writer buffer for each connection.
 	// Larger buffers can improve performance for large pipelines and commands with many arguments.
 	// Smaller buffers can improve memory usage for larger pools.
 	//
-	// default: 0.5MiB (524288 bytes)
+	// default: 256KiB (262144 bytes)
 	WriteBufferSize int
 
 	// PoolFIFO type of connection pool.

osscluster.go

@@ -96,14 +96,14 @@ type ClusterOptions struct {
 	// Larger buffers can improve performance for commands that return large responses.
 	// Smaller buffers can improve memory usage for larger pools.
 	//
-	// default: 0.5MiB (524288 bytes)
+	// default: 256KiB (262144 bytes)
 	ReadBufferSize int
 
 	// WriteBufferSize is the size of the bufio.Writer buffer for each connection.
 	// Larger buffers can improve performance for large pipelines and commands with many arguments.
 	// Smaller buffers can improve memory usage for larger pools.
 	//
-	// default: 0.5MiB (524288 bytes)
+	// default: 256KiB (262144 bytes)
 	WriteBufferSize int
 
 	TLSConfig *tls.Config

ring.go

@@ -128,14 +128,14 @@ type RingOptions struct {
 	// Larger buffers can improve performance for commands that return large responses.
 	// Smaller buffers can improve memory usage for larger pools.
 	//
-	// default: 0.5MiB (524288 bytes)
+	// default: 256KiB (262144 bytes)
 	ReadBufferSize int
 
 	// WriteBufferSize is the size of the bufio.Writer buffer for each connection.
 	// Larger buffers can improve performance for large pipelines and commands with many arguments.
 	// Smaller buffers can improve memory usage for larger pools.
 	//
-	// default: 0.5MiB (524288 bytes)
+	// default: 256KiB (262144 bytes)
 	WriteBufferSize int
 
 	TLSConfig *tls.Config

sentinel.go

@@ -90,6 +90,20 @@ type FailoverOptions struct {
 	WriteTimeout          time.Duration
 	ContextTimeoutEnabled bool
 
+	// ReadBufferSize is the size of the bufio.Reader buffer for each connection.
+	// Larger buffers can improve performance for commands that return large responses.
+	// Smaller buffers can improve memory usage for larger pools.
+	//
+	// default: 256KiB (262144 bytes)
+	ReadBufferSize int
+
+	// WriteBufferSize is the size of the bufio.Writer buffer for each connection.
+	// Larger buffers can improve performance for large pipelines and commands with many arguments.
+	// Smaller buffers can improve memory usage for larger pools.
+	//
+	// default: 256KiB (262144 bytes)
+	WriteBufferSize int
+
 	PoolFIFO bool
 
 	PoolSize        int
@@ -138,6 +152,9 @@ func (opt *FailoverOptions) clientOptions() *Options {
 		MinRetryBackoff: opt.MinRetryBackoff,
 		MaxRetryBackoff: opt.MaxRetryBackoff,
 
+		ReadBufferSize:  opt.ReadBufferSize,
+		WriteBufferSize: opt.WriteBufferSize,
+
 		DialTimeout:           opt.DialTimeout,
 		ReadTimeout:           opt.ReadTimeout,
 		WriteTimeout:          opt.WriteTimeout,
@@ -178,6 +195,9 @@ func (opt *FailoverOptions) sentinelOptions(addr string) *Options {
 		MinRetryBackoff: opt.MinRetryBackoff,
 		MaxRetryBackoff: opt.MaxRetryBackoff,
 
+		ReadBufferSize:  opt.ReadBufferSize,
+		WriteBufferSize: opt.WriteBufferSize,
+
 		DialTimeout:           opt.DialTimeout,
 		ReadTimeout:           opt.ReadTimeout,
 		WriteTimeout:          opt.WriteTimeout,
@@ -224,6 +244,9 @@ func (opt *FailoverOptions) clusterOptions() *ClusterOptions {
 		MinRetryBackoff: opt.MinRetryBackoff,
 		MaxRetryBackoff: opt.MaxRetryBackoff,
 
+		ReadBufferSize:  opt.ReadBufferSize,
+		WriteBufferSize: opt.WriteBufferSize,
+
 		DialTimeout:           opt.DialTimeout,
 		ReadTimeout:           opt.ReadTimeout,
 		WriteTimeout:          opt.WriteTimeout,