Add MaxConnAge

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+- New option MinIdleConns.
+- New option MaxConnAge.
+- PoolStats.FreeConns is renamed to PoolStats.IdleConns.
+
 ## v6.13
 
 - Ring got new options called `HashReplicas` and `Hash`. It is recommended to set `HashReplicas = 1000` for better keys distribution between shards.

cluster.go

@@ -65,6 +65,8 @@ type ClusterOptions struct {
 
 	// PoolSize applies per cluster node and not for the whole cluster.
 	PoolSize           int
+	MinIdleConns       int
+	MaxConnAge         time.Duration
 	PoolTimeout        time.Duration
 	IdleTimeout        time.Duration
 	IdleCheckFrequency time.Duration
@@ -130,10 +132,11 @@ func (opt *ClusterOptions) clientOptions() *Options {
 		ReadTimeout:  opt.ReadTimeout,
 		WriteTimeout: opt.WriteTimeout,
 
-		PoolSize:    opt.PoolSize,
-		PoolTimeout: opt.PoolTimeout,
-		IdleTimeout: opt.IdleTimeout,
-
+		PoolSize:           opt.PoolSize,
+		MinIdleConns:       opt.MinIdleConns,
+		MaxConnAge:         opt.MaxConnAge,
+		PoolTimeout:        opt.PoolTimeout,
+		IdleTimeout:        opt.IdleTimeout,
 		IdleCheckFrequency: disableIdleCheck,
 
 		TLSConfig: opt.TLSConfig,
@@ -1106,7 +1109,7 @@ func (c *ClusterClient) PoolStats() *PoolStats {
 		acc.Timeouts += s.Timeouts
 
 		acc.TotalConns += s.TotalConns
-		acc.FreeConns += s.FreeConns
+		acc.IdleConns += s.IdleConns
 		acc.StaleConns += s.StaleConns
 	}
 
@@ -1117,7 +1120,7 @@ func (c *ClusterClient) PoolStats() *PoolStats {
 		acc.Timeouts += s.Timeouts
 
 		acc.TotalConns += s.TotalConns
-		acc.FreeConns += s.FreeConns
+		acc.IdleConns += s.IdleConns
 		acc.StaleConns += s.StaleConns
 	}
 

cluster_test.go

@@ -557,13 +557,13 @@ var _ = Describe("ClusterClient", func() {
 		It("removes idle connections", func() {
 			stats := client.PoolStats()
 			Expect(stats.TotalConns).NotTo(BeZero())
-			Expect(stats.FreeConns).NotTo(BeZero())
+			Expect(stats.IdleConns).NotTo(BeZero())
 
 			time.Sleep(2 * time.Second)
 
 			stats = client.PoolStats()
 			Expect(stats.TotalConns).To(BeZero())
-			Expect(stats.FreeConns).To(BeZero())
+			Expect(stats.IdleConns).To(BeZero())
 		})
 
 		It("returns an error when there are no attempts left", func() {

commands_test.go

@@ -42,7 +42,7 @@ var _ = Describe("Commands", func() {
 			Expect(stats.Misses).To(Equal(uint32(1)))
 			Expect(stats.Timeouts).To(Equal(uint32(0)))
 			Expect(stats.TotalConns).To(Equal(uint32(1)))
-			Expect(stats.FreeConns).To(Equal(uint32(1)))
+			Expect(stats.IdleConns).To(Equal(uint32(1)))
 		})
 
 		It("should Echo", func() {

internal/pool/conn.go

@@ -18,9 +18,9 @@ type Conn struct {
 
 	concurrentReadWrite bool
 
-	Inited bool
-	pooled bool
-	usedAt atomic.Value
+	InitedAt time.Time
+	pooled   bool
+	usedAt   atomic.Value
 }
 
 func NewConn(netConn net.Conn) *Conn {
@@ -47,10 +47,6 @@ func (cn *Conn) SetNetConn(netConn net.Conn) {
 	cn.Rd.Reset(netConn)
 }
 
-func (cn *Conn) IsStale(timeout time.Duration) bool {
-	return timeout > 0 && time.Since(cn.UsedAt()) > timeout
-}
-
 func (cn *Conn) SetReadTimeout(timeout time.Duration) {
 	now := time.Now()
 	cn.SetUsedAt(now)

internal/pool/pool.go

@@ -28,7 +28,6 @@ type Stats struct {
 	Timeouts uint32 // number of times a wait timeout occurred
 
 	TotalConns uint32 // number of total connections in the pool
-	FreeConns  uint32 // deprecated - use IdleConns
 	IdleConns  uint32 // number of idle connections in the pool
 	StaleConns uint32 // number of stale connections removed from the pool
 }
@@ -54,6 +53,7 @@ type Options struct {
 
 	PoolSize           int
 	MinIdleConns       int
+	MaxConnAge         time.Duration
 	PoolTimeout        time.Duration
 	IdleTimeout        time.Duration
 	IdleCheckFrequency time.Duration
@@ -223,8 +223,8 @@ func (p *ConnPool) Get() (*Conn, error) {
 			break
 		}
 
-		if cn.IsStale(p.opt.IdleTimeout) {
-			p.CloseConn(cn)
+		if p.isStaleConn(cn) {
+			_ = p.CloseConn(cn)
 			continue
 		}
 
@@ -343,12 +343,12 @@ func (p *ConnPool) closeConn(cn *Conn) error {
 // Len returns total number of connections.
 func (p *ConnPool) Len() int {
 	p.connsMu.Lock()
-	n := p.poolSize
+	n := len(p.conns)
 	p.connsMu.Unlock()
 	return n
 }
 
-// FreeLen returns number of idle connections.
+// IdleLen returns number of idle connections.
 func (p *ConnPool) IdleLen() int {
 	p.connsMu.Lock()
 	n := p.idleConnsLen
@@ -364,7 +364,6 @@ func (p *ConnPool) Stats() *Stats {
 		Timeouts: atomic.LoadUint32(&p.stats.Timeouts),
 
 		TotalConns: uint32(p.Len()),
-		FreeConns:  uint32(idleLen),
 		IdleConns:  uint32(idleLen),
 		StaleConns: atomic.LoadUint32(&p.stats.StaleConns),
 	}
@@ -415,7 +414,7 @@ func (p *ConnPool) reapStaleConn() *Conn {
 	}
 
 	cn := p.idleConns[0]
-	if !cn.IsStale(p.opt.IdleTimeout) {
+	if !p.isStaleConn(cn) {
 		return nil
 	}
 
@@ -466,3 +465,19 @@ func (p *ConnPool) reaper(frequency time.Duration) {
 		atomic.AddUint32(&p.stats.StaleConns, uint32(n))
 	}
 }
+
+func (p *ConnPool) isStaleConn(cn *Conn) bool {
+	if p.opt.IdleTimeout == 0 && p.opt.MaxConnAge == 0 {
+		return false
+	}
+
+	now := time.Now()
+	if p.opt.IdleTimeout > 0 && now.Sub(cn.UsedAt()) >= p.opt.IdleTimeout {
+		return true
+	}
+	if p.opt.MaxConnAge > 0 && now.Sub(cn.InitedAt) >= p.opt.MaxConnAge {
+		return true
+	}
+
+	return false
+}

internal/pool/pool_test.go

@@ -248,114 +248,128 @@ var _ = Describe("MinIdleConns", func() {
 
 var _ = Describe("conns reaper", func() {
 	const idleTimeout = time.Minute
+	const maxAge = time.Hour
 
 	var connPool *pool.ConnPool
-	var conns, idleConns, closedConns []*pool.Conn
+	var conns, staleConns, closedConns []*pool.Conn
 
-	BeforeEach(func() {
-		conns = nil
-		closedConns = nil
+	assert := func(typ string) {
+		BeforeEach(func() {
+			closedConns = nil
+			connPool = pool.NewConnPool(&pool.Options{
+				Dialer:             dummyDialer,
+				PoolSize:           10,
+				IdleTimeout:        idleTimeout,
+				MaxConnAge:         maxAge,
+				PoolTimeout:        time.Second,
+				IdleCheckFrequency: time.Hour,
+				OnClose: func(cn *pool.Conn) error {
+					closedConns = append(closedConns, cn)
+					return nil
+				},
+			})
 
-		connPool = pool.NewConnPool(&pool.Options{
-			Dialer:             dummyDialer,
-			PoolSize:           10,
-			PoolTimeout:        time.Second,
-			IdleTimeout:        idleTimeout,
-			IdleCheckFrequency: time.Hour,
+			conns = nil
 
-			OnClose: func(cn *pool.Conn) error {
-				closedConns = append(closedConns, cn)
-				return nil
-			},
-		})
-
-		// add stale connections
-		idleConns = nil
-		for i := 0; i < 3; i++ {
-			cn, err := connPool.Get()
-			Expect(err).NotTo(HaveOccurred())
-			cn.SetUsedAt(time.Now().Add(-2 * idleTimeout))
-			conns = append(conns, cn)
-			idleConns = append(idleConns, cn)
-		}
-
-		// add fresh connections
-		for i := 0; i < 3; i++ {
-			cn, err := connPool.Get()
-			Expect(err).NotTo(HaveOccurred())
-			conns = append(conns, cn)
-		}
-
-		for _, cn := range conns {
-			connPool.Put(cn)
-		}
-
-		Expect(connPool.Len()).To(Equal(6))
-		Expect(connPool.IdleLen()).To(Equal(6))
-
-		n, err := connPool.ReapStaleConns()
-		Expect(err).NotTo(HaveOccurred())
-		Expect(n).To(Equal(3))
-	})
-
-	AfterEach(func() {
-		_ = connPool.Close()
-		Expect(connPool.Len()).To(Equal(0))
-		Expect(connPool.IdleLen()).To(Equal(0))
-		Expect(len(closedConns)).To(Equal(len(conns)))
-		Expect(closedConns).To(ConsistOf(conns))
-	})
-
-	It("reaps stale connections", func() {
-		Expect(connPool.Len()).To(Equal(3))
-		Expect(connPool.IdleLen()).To(Equal(3))
-	})
-
-	It("does not reap fresh connections", func() {
-		n, err := connPool.ReapStaleConns()
-		Expect(err).NotTo(HaveOccurred())
-		Expect(n).To(Equal(0))
-	})
-
-	It("stale connections are closed", func() {
-		Expect(len(closedConns)).To(Equal(len(idleConns)))
-		Expect(closedConns).To(ConsistOf(idleConns))
-	})
-
-	It("pool is functional", func() {
-		for j := 0; j < 3; j++ {
-			var freeCns []*pool.Conn
+			// add stale connections
+			staleConns = nil
 			for i := 0; i < 3; i++ {
 				cn, err := connPool.Get()
 				Expect(err).NotTo(HaveOccurred())
-				Expect(cn).NotTo(BeNil())
-				freeCns = append(freeCns, cn)
+				switch typ {
+				case "idle":
+					cn.SetUsedAt(time.Now().Add(-2 * idleTimeout))
+				case "aged":
+					cn.InitedAt = time.Now().Add(-2 * maxAge)
+				}
+				conns = append(conns, cn)
+				staleConns = append(staleConns, cn)
 			}
 
-			Expect(connPool.Len()).To(Equal(3))
-			Expect(connPool.IdleLen()).To(Equal(0))
+			// add fresh connections
+			for i := 0; i < 3; i++ {
+				cn, err := connPool.Get()
+				Expect(err).NotTo(HaveOccurred())
+				conns = append(conns, cn)
+			}
 
-			cn, err := connPool.Get()
-			Expect(err).NotTo(HaveOccurred())
-			Expect(cn).NotTo(BeNil())
-			conns = append(conns, cn)
-
-			Expect(connPool.Len()).To(Equal(4))
-			Expect(connPool.IdleLen()).To(Equal(0))
-
-			connPool.Remove(cn)
-
-			Expect(connPool.Len()).To(Equal(3))
-			Expect(connPool.IdleLen()).To(Equal(0))
-
-			for _, cn := range freeCns {
+			for _, cn := range conns {
+				if cn.InitedAt.IsZero() {
+					cn.InitedAt = time.Now()
+				}
 				connPool.Put(cn)
 			}
 
+			Expect(connPool.Len()).To(Equal(6))
+			Expect(connPool.IdleLen()).To(Equal(6))
+
+			n, err := connPool.ReapStaleConns()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(n).To(Equal(3))
+		})
+
+		AfterEach(func() {
+			_ = connPool.Close()
+			Expect(connPool.Len()).To(Equal(0))
+			Expect(connPool.IdleLen()).To(Equal(0))
+			Expect(len(closedConns)).To(Equal(len(conns)))
+			Expect(closedConns).To(ConsistOf(conns))
+		})
+
+		It("reaps stale connections", func() {
 			Expect(connPool.Len()).To(Equal(3))
 			Expect(connPool.IdleLen()).To(Equal(3))
-		}
-	})
+		})
+
+		It("does not reap fresh connections", func() {
+			n, err := connPool.ReapStaleConns()
+			Expect(err).NotTo(HaveOccurred())
+			Expect(n).To(Equal(0))
+		})
+
+		It("stale connections are closed", func() {
+			Expect(len(closedConns)).To(Equal(len(staleConns)))
+			Expect(closedConns).To(ConsistOf(staleConns))
+		})
+
+		It("pool is functional", func() {
+			for j := 0; j < 3; j++ {
+				var freeCns []*pool.Conn
+				for i := 0; i < 3; i++ {
+					cn, err := connPool.Get()
+					Expect(err).NotTo(HaveOccurred())
+					Expect(cn).NotTo(BeNil())
+					freeCns = append(freeCns, cn)
+				}
+
+				Expect(connPool.Len()).To(Equal(3))
+				Expect(connPool.IdleLen()).To(Equal(0))
+
+				cn, err := connPool.Get()
+				Expect(err).NotTo(HaveOccurred())
+				Expect(cn).NotTo(BeNil())
+				conns = append(conns, cn)
+
+				Expect(connPool.Len()).To(Equal(4))
+				Expect(connPool.IdleLen()).To(Equal(0))
+
+				connPool.Remove(cn)
+
+				Expect(connPool.Len()).To(Equal(3))
+				Expect(connPool.IdleLen()).To(Equal(0))
+
+				for _, cn := range freeCns {
+					connPool.Put(cn)
+				}
+
+				Expect(connPool.Len()).To(Equal(3))
+				Expect(connPool.IdleLen()).To(Equal(3))
+			}
+		})
+	}
+
+	assert("idle")
+	assert("aged")
 })
 
 var _ = Describe("race", func() {

options.go

@@ -62,6 +62,9 @@ type Options struct {
 	// Minimum number of idle connections which is useful when establishing
 	// new connection is slow.
 	MinIdleConns int
+	// Connection age at which client retires (closes) the connection.
+	// Default is to not close aged connections.
+	MaxConnAge time.Duration
 	// Amount of time client waits for connection if all connections
 	// are busy before returning an error.
 	// Default is ReadTimeout + 1 second.
@@ -201,6 +204,7 @@ func newConnPool(opt *Options) *pool.ConnPool {
 		Dialer:             opt.Dialer,
 		PoolSize:           opt.PoolSize,
 		MinIdleConns:       opt.MinIdleConns,
+		MaxConnAge:         opt.MaxConnAge,
 		PoolTimeout:        opt.PoolTimeout,
 		IdleTimeout:        opt.IdleTimeout,
 		IdleCheckFrequency: opt.IdleCheckFrequency,

pool_test.go

@@ -13,7 +13,10 @@ var _ = Describe("pool", func() {
 	var client *redis.Client
 
 	BeforeEach(func() {
-		client = redis.NewClient(redisOptions())
+		opt := redisOptions()
+		opt.MinIdleConns = 0
+		opt.MaxConnAge = 0
+		client = redis.NewClient(opt)
 		Expect(client.FlushDB().Err()).NotTo(HaveOccurred())
 	})
 
@@ -124,7 +127,6 @@ var _ = Describe("pool", func() {
 			Misses:     1,
 			Timeouts:   0,
 			TotalConns: 1,
-			FreeConns:  1,
 			IdleConns:  1,
 			StaleConns: 0,
 		}))
@@ -137,7 +139,7 @@ var _ = Describe("pool", func() {
 			Misses:     1,
 			Timeouts:   0,
 			TotalConns: 0,
-			FreeConns:  0,
+			IdleConns:  0,
 			StaleConns: 1,
 		}))
 	})

pubsub_test.go

@@ -16,7 +16,10 @@ var _ = Describe("PubSub", func() {
 	var client *redis.Client
 
 	BeforeEach(func() {
-		client = redis.NewClient(redisOptions())
+		opt := redisOptions()
+		opt.MinIdleConns = 0
+		opt.MaxConnAge = 0
+		client = redis.NewClient(opt)
 		Expect(client.FlushDB().Err()).NotTo(HaveOccurred())
 	})
 

redis.go

@@ -50,7 +50,7 @@ func (c *baseClient) newConn() (*pool.Conn, error) {
 		return nil, err
 	}
 
-	if !cn.Inited {
+	if cn.InitedAt.IsZero() {
 		if err := c.initConn(cn); err != nil {
 			_ = c.connPool.CloseConn(cn)
 			return nil, err
@@ -66,7 +66,7 @@ func (c *baseClient) getConn() (*pool.Conn, error) {
 		return nil, err
 	}
 
-	if !cn.Inited {
+	if cn.InitedAt.IsZero() {
 		err := c.initConn(cn)
 		if err != nil {
 			c.connPool.Remove(cn)
@@ -88,7 +88,7 @@ func (c *baseClient) releaseConn(cn *pool.Conn, err error) bool {
 }
 
 func (c *baseClient) initConn(cn *pool.Conn) error {
-	cn.Inited = true
+	cn.InitedAt = time.Now()
 
 	if c.opt.Password == "" &&
 		c.opt.DB == 0 &&

ring.go

@@ -68,6 +68,8 @@ type RingOptions struct {
 	WriteTimeout time.Duration
 
 	PoolSize           int
+	MinIdleConns       int
+	MaxConnAge         time.Duration
 	PoolTimeout        time.Duration
 	IdleTimeout        time.Duration
 	IdleCheckFrequency time.Duration
@@ -108,6 +110,8 @@ func (opt *RingOptions) clientOptions() *Options {
 		WriteTimeout: opt.WriteTimeout,
 
 		PoolSize:           opt.PoolSize,
+		MinIdleConns:       opt.MinIdleConns,
+		MaxConnAge:         opt.MaxConnAge,
 		PoolTimeout:        opt.PoolTimeout,
 		IdleTimeout:        opt.IdleTimeout,
 		IdleCheckFrequency: opt.IdleCheckFrequency,
@@ -404,7 +408,7 @@ func (c *Ring) PoolStats() *PoolStats {
 		acc.Misses += s.Misses
 		acc.Timeouts += s.Timeouts
 		acc.TotalConns += s.TotalConns
-		acc.FreeConns += s.FreeConns
+		acc.IdleConns += s.IdleConns
 	}
 	return &acc
 }