diff --git a/common/fs/fs.go b/common/fs/fs.go
index da4d903faf..6b9eb41629 100644
--- a/common/fs/fs.go
+++ b/common/fs/fs.go
@@ -10,6 +10,7 @@ import (
 // Interface is the filesystem interface type.
 type Interface interface {
 	ReadDir(string) ([]os.FileInfo, error)
+	ReadDirNames(string) ([]string, error)
 	ReadFile(string) ([]byte, error)
 	Lstat(string, *syscall.Stat_t) error
 	Stat(string, *syscall.Stat_t) error
@@ -25,6 +26,15 @@ func (realFS) ReadDir(path string) ([]os.FileInfo, error) {
 	return ioutil.ReadDir(path)
 }
 
+func (realFS) ReadDirNames(path string) ([]string, error) {
+	fh, err := os.Open(path)
+	if err != nil {
+		return nil, err
+	}
+	defer fh.Close()
+	return fh.Readdirnames(-1)
+}
+
 func (realFS) ReadFile(path string) ([]byte, error) {
 	return ioutil.ReadFile(path)
 }
@@ -48,6 +58,11 @@ func ReadDir(path string) ([]os.FileInfo, error) {
 	return fs.ReadDir(path)
 }
 
+// ReadDirNames see os.File.ReadDirNames
+func ReadDirNames(path string) ([]string, error) {
+	return fs.ReadDirNames(path)
+}
+
 // ReadFile see ioutil.ReadFile
 func ReadFile(path string) ([]byte, error) {
 	return fs.ReadFile(path)
diff --git a/probe/endpoint/procspy/benchmark_internal_test.go b/probe/endpoint/procspy/benchmark_internal_test.go
index ec1dea59c2..1e48aab06e 100644
--- a/probe/endpoint/procspy/benchmark_internal_test.go
+++ b/probe/endpoint/procspy/benchmark_internal_test.go
@@ -6,13 +6,16 @@ import (
 )
 
 func BenchmarkParseConnectionsBaseline(b *testing.B) {
-	readFile = func(string, *bytes.Buffer) error { return nil }
+	readFile = func(string, *bytes.Buffer) (int64, error) { return 0, nil }
 	benchmarkConnections(b)
 	// 333 ns/op, 0 allocs/op
 }
 
 func BenchmarkParseConnectionsFixture(b *testing.B) {
-	readFile = func(_ string, buf *bytes.Buffer) error { _, err := buf.Write(fixture); return err }
+	readFile = func(_ string, buf *bytes.Buffer) (int64, error) {
+		n, err := buf.Write(fixture)
+		return int64(n), err
+	}
 	benchmarkConnections(b)
 	// 15553 ns/op, 12 allocs/op
 }
diff --git a/probe/endpoint/procspy/proc.go b/probe/endpoint/procspy/proc.go
index 312c0177ee..dd8c47ae14 100644
--- a/probe/endpoint/procspy/proc.go
+++ b/probe/endpoint/procspy/proc.go
@@ -24,38 +24,41 @@ func SetProcRoot(root string) {
 // walkProcPid walks over all numerical (PID) /proc entries, and sees if their
 // ./fd/* files are symlink to sockets. Returns a map from socket ID (inode)
 // to PID. Will return an error if /proc isn't there.
-func walkProcPid(buf *bytes.Buffer, walker process.Walker) (map[uint64]Proc, error) {
+func walkProcPid(buf *bytes.Buffer, walker process.Walker) (map[uint64]*Proc, error) {
 	var (
-		res        = map[uint64]Proc{}
-		namespaces = map[uint64]struct{}{}
+		res        = map[uint64]*Proc{}
+		namespaces = map[uint64]bool{} // map namespace id -> has connections
 		statT      syscall.Stat_t
 	)
 
 	walker.Walk(func(p process.Process) {
 		dirName := strconv.Itoa(p.PID)
 		fdBase := filepath.Join(procRoot, dirName, "fd")
-		fds, err := fs.ReadDir(fdBase)
-		if err != nil {
-			// Process is be gone by now, or we don't have access.
-			return
-		}
 
 		// Read network namespace, and if we haven't seen it before,
 		// read /proc/<pid>/net/tcp
-		err = fs.Lstat(filepath.Join(procRoot, dirName, "/ns/net"), &statT)
-		if err != nil {
+		if err := fs.Lstat(filepath.Join(procRoot, dirName, "/ns/net"), &statT); err != nil {
 			return
 		}
-
-		if _, ok := namespaces[statT.Ino]; !ok {
-			namespaces[statT.Ino] = struct{}{}
-			readFile(filepath.Join(procRoot, dirName, "/net/tcp"), buf)
-			readFile(filepath.Join(procRoot, dirName, "/net/tcp6"), buf)
+		hasConns, ok := namespaces[statT.Ino]
+		if !ok {
+			read, err := readFile(filepath.Join(procRoot, dirName, "/net/tcp"), buf)
+			hasConns = err == nil && read > 0
+			namespaces[statT.Ino] = hasConns
+		}
+		if !hasConns {
+			return
 		}
 
+		fds, err := fs.ReadDirNames(fdBase)
+		if err != nil {
+			// Process is be gone by now, or we don't have access.
+			return
+		}
+		var proc *Proc
 		for _, fd := range fds {
 			// Direct use of syscall.Stat() to save garbage.
-			err = fs.Stat(filepath.Join(fdBase, fd.Name()), &statT)
+			err = fs.Stat(filepath.Join(fdBase, fd), &statT)
 			if err != nil {
 				continue
 			}
@@ -64,11 +67,13 @@ func walkProcPid(buf *bytes.Buffer, walker process.Walker) (map[uint64]Proc, err
 			if statT.Mode&syscall.S_IFMT != syscall.S_IFSOCK {
 				continue
 			}
-
-			res[statT.Ino] = Proc{
-				PID:  uint(p.PID),
-				Name: p.Comm,
+			if proc == nil {
+				proc = &Proc{
+					PID:  uint(p.PID),
+					Name: p.Comm,
+				}
 			}
+			res[statT.Ino] = proc
 		}
 	})
 
@@ -78,12 +83,11 @@ func walkProcPid(buf *bytes.Buffer, walker process.Walker) (map[uint64]Proc, err
 // readFile reads an arbitrary file into a buffer. It's a variable so it can
 // be overwritten for benchmarks. That's bad practice and we should change it
 // to be a dependency.
-var readFile = func(filename string, buf *bytes.Buffer) error {
+var readFile = func(filename string, buf *bytes.Buffer) (int64, error) {
 	f, err := fs.Open(filename)
 	if err != nil {
-		return err
+		return -1, err
 	}
-	_, err = buf.ReadFrom(f)
-	f.Close()
-	return err
+	defer f.Close()
+	return buf.ReadFrom(f)
 }
diff --git a/probe/endpoint/procspy/proc_internal_test.go b/probe/endpoint/procspy/proc_internal_test.go
index 4ebd005524..19c9aa3811 100644
--- a/probe/endpoint/procspy/proc_internal_test.go
+++ b/probe/endpoint/procspy/proc_internal_test.go
@@ -33,6 +33,12 @@ var mockFS = fs.Dir("",
 					FStat: syscall.Stat_t{},
 				},
 			),
+			fs.Dir("net",
+				fs.File{
+					FName:     "tcp",
+					FContents: "I'm a little teapot",
+				},
+			),
 			fs.File{
 				FName:     "stat",
 				FContents: "1 na R 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 1",
@@ -50,7 +56,7 @@ func TestWalkProcPid(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	want := map[uint64]Proc{
+	want := map[uint64]*Proc{
 		45: {
 			PID:  1,
 			Name: "foo",
diff --git a/probe/endpoint/procspy/spy_linux.go b/probe/endpoint/procspy/spy_linux.go
index 29634edb0b..68b0d7c0bc 100644
--- a/probe/endpoint/procspy/spy_linux.go
+++ b/probe/endpoint/procspy/spy_linux.go
@@ -16,7 +16,7 @@ var bufPool = sync.Pool{
 type pnConnIter struct {
 	pn    *ProcNet
 	buf   *bytes.Buffer
-	procs map[uint64]Proc
+	procs map[uint64]*Proc
 }
 
 func (c *pnConnIter) Next() *Connection {
@@ -27,7 +27,7 @@ func (c *pnConnIter) Next() *Connection {
 		return nil
 	}
 	if proc, ok := c.procs[n.inode]; ok {
-		n.Proc = proc
+		n.Proc = *proc
 	}
 	return n
 }
@@ -38,7 +38,7 @@ var cbConnections = func(processes bool, walker process.Walker) (ConnIter, error
 	buf := bufPool.Get().(*bytes.Buffer)
 	buf.Reset()
 
-	var procs map[uint64]Proc
+	var procs map[uint64]*Proc
 	if processes {
 		var err error
 		if procs, err = walkProcPid(buf, walker); err != nil {
diff --git a/probe/process/cache.go b/probe/process/cache.go
new file mode 100644
index 0000000000..e17713e64e
--- /dev/null
+++ b/probe/process/cache.go
@@ -0,0 +1,72 @@
+package process
+
+import (
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/armon/go-metrics"
+	"github.com/coocood/freecache"
+
+	"github.com/weaveworks/scope/common/fs"
+)
+
+const (
+	generalTimeout = 30 // seconds
+	statsTimeout   = 10 //seconds
+)
+
+var (
+	hitMetricsKey  = []string{"process", "cache", "hit"}
+	missMetricsKey = []string{"process", "cache", "miss"}
+)
+
+var fileCache = freecache.NewCache(1024 * 16)
+
+type entry struct {
+	buf []byte
+	err error
+	ts  time.Time
+}
+
+func cachedReadFile(path string) ([]byte, error) {
+	key := []byte(path)
+	if v, err := fileCache.Get(key); err == nil {
+		metrics.IncrCounter(hitMetricsKey, 1.0)
+		return v, nil
+	}
+
+	buf, err := fs.ReadFile(path)
+	fileCache.Set(key, buf, generalTimeout)
+	metrics.IncrCounter(missMetricsKey, 1.0)
+	return buf, err
+}
+
+// we cache the stats, but for a shorter period
+func readStats(path string) (int, int, error) {
+	var (
+		key = []byte(path)
+		buf []byte
+		err error
+	)
+	if buf, err = fileCache.Get(key); err == nil {
+		metrics.IncrCounter(hitMetricsKey, 1.0)
+	} else {
+		buf, err = fs.ReadFile(path)
+		if err != nil {
+			return -1, -1, err
+		}
+		fileCache.Set(key, buf, statsTimeout)
+		metrics.IncrCounter(missMetricsKey, 1.0)
+	}
+	splits := strings.Fields(string(buf))
+	ppid, err := strconv.Atoi(splits[3])
+	if err != nil {
+		return -1, -1, err
+	}
+	threads, err := strconv.Atoi(splits[19])
+	if err != nil {
+		return -1, -1, err
+	}
+	return ppid, threads, nil
+}
diff --git a/probe/process/walker_linux.go b/probe/process/walker_linux.go
index 7b04311749..725545444a 100644
--- a/probe/process/walker_linux.go
+++ b/probe/process/walker_linux.go
@@ -23,41 +23,30 @@ func NewWalker(procRoot string) Walker {
 // passes one-by-one to the supplied function. Walk is only made public
 // so that is can be tested.
 func (w *walker) Walk(f func(Process)) error {
-	dirEntries, err := fs.ReadDir(w.procRoot)
+	dirEntries, err := fs.ReadDirNames(w.procRoot)
 	if err != nil {
 		return err
 	}
 
-	for _, dirEntry := range dirEntries {
-		filename := dirEntry.Name()
+	for _, filename := range dirEntries {
 		pid, err := strconv.Atoi(filename)
 		if err != nil {
 			continue
 		}
 
-		stat, err := fs.ReadFile(path.Join(w.procRoot, filename, "stat"))
+		ppid, threads, err := readStats(path.Join(w.procRoot, filename, "stat"))
 		if err != nil {
 			continue
 		}
-		splits := strings.Fields(string(stat))
-		ppid, err := strconv.Atoi(splits[3])
-		if err != nil {
-			return err
-		}
-
-		threads, err := strconv.Atoi(splits[19])
-		if err != nil {
-			return err
-		}
 
 		cmdline := ""
-		if cmdlineBuf, err := fs.ReadFile(path.Join(w.procRoot, filename, "cmdline")); err == nil {
+		if cmdlineBuf, err := cachedReadFile(path.Join(w.procRoot, filename, "cmdline")); err == nil {
 			cmdlineBuf = bytes.Replace(cmdlineBuf, []byte{'\000'}, []byte{' '}, -1)
 			cmdline = string(cmdlineBuf)
 		}
 
 		comm := "(unknown)"
-		if commBuf, err := fs.ReadFile(path.Join(w.procRoot, filename, "comm")); err == nil {
+		if commBuf, err := cachedReadFile(path.Join(w.procRoot, filename, "comm")); err == nil {
 			comm = strings.TrimSpace(string(commBuf))
 		}
 
diff --git a/test/fs/fs.go b/test/fs/fs.go
index 56b6a87d56..b59f37dc83 100644
--- a/test/fs/fs.go
+++ b/test/fs/fs.go
@@ -89,6 +89,24 @@ func (p dir) ReadDir(path string) ([]os.FileInfo, error) {
 	return fs.ReadDir(tail)
 }
 
+func (p dir) ReadDirNames(path string) ([]string, error) {
+	if path == "/" {
+		result := []string{}
+		for _, v := range p.entries {
+			result = append(result, v.Name())
+		}
+		return result, nil
+	}
+
+	head, tail := split(path)
+	fs, ok := p.entries[head]
+	if !ok {
+		return nil, fmt.Errorf("Not found: %s", path)
+	}
+
+	return fs.ReadDirNames(tail)
+}
+
 func (p dir) ReadFile(path string) ([]byte, error) {
 	if path == "/" {
 		return nil, fmt.Errorf("I'm a directory!")
@@ -156,6 +174,11 @@ func (p File) ReadDir(path string) ([]os.FileInfo, error) {
 	return nil, fmt.Errorf("I'm a file!")
 }
 
+// ReadDirNames implements FS
+func (p File) ReadDirNames(path string) ([]string, error) {
+	return nil, fmt.Errorf("I'm a file!")
+}
+
 // ReadFile implements FS
 func (p File) ReadFile(path string) ([]byte, error) {
 	if path != "/" {
diff --git a/vendor/github.com/coocood/freecache/LICENSE b/vendor/github.com/coocood/freecache/LICENSE
new file mode 100644
index 0000000000..fb5a06b4b9
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/LICENSE
@@ -0,0 +1,21 @@
+The MIT License
+
+Copyright (c) 2015 Ewan Chou.
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
\ No newline at end of file
diff --git a/vendor/github.com/coocood/freecache/README.md b/vendor/github.com/coocood/freecache/README.md
new file mode 100644
index 0000000000..8b73c81e70
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/README.md
@@ -0,0 +1,114 @@
+#FreeCache - A cache library for Go with zero GC overhead.
+
+Long lived objects in memory introduce expensive GC overhead, the GC latency can go up to hundreds of milliseconds with just a few millions of live objects. 
+With FreeCache, you can cache unlimited number of objects in memory without increased GC latency. 
+
+[![Build Status](https://travis-ci.org/coocood/freecache.png?branch=master)](https://travis-ci.org/coocood/freecache)
+[![GoCover](http://gocover.io/_badge/github.com/coocood/freecache)](http://gocover.io/github.com/coocood/freecache)
+[![GoDoc](https://godoc.org/github.com/coocood/freecache?status.svg)](https://godoc.org/github.com/coocood/freecache)
+
+##About GC Pause Issue
+
+Here is the demo code for the GC pause issue, you can run it yourself.
+On my laptop, GC pause with FreeCache is under 200us, but with map, it is more than 300ms.
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/coocood/freecache"
+    "runtime"
+    "runtime/debug"
+    "time"
+)
+
+var mapCache map[string][]byte
+
+func GCPause() time.Duration {
+    runtime.GC()
+    var stats debug.GCStats
+    debug.ReadGCStats(&stats)
+    return stats.Pause[0]
+}
+
+func main() {
+    n := 3000 * 1000
+    freeCache := freecache.NewCache(512 * 1024 * 1024)
+    debug.SetGCPercent(10)
+    for i := 0; i < n; i++ {
+        key := fmt.Sprintf("key%v", i)
+        val := make([]byte, 10)
+        freeCache.Set([]byte(key), val, 0)
+    }
+    fmt.Println("GC pause with free cache:", GCPause())
+    freeCache = nil
+    mapCache = make(map[string][]byte)
+    for i := 0; i < n; i++ {
+        key := fmt.Sprintf("key%v", i)
+        val := make([]byte, 10)
+        mapCache[key] = val
+    }
+    fmt.Println("GC pause with map cache:", GCPause())
+}
+```
+
+##Features
+* Store hundreds of millions of entries
+* Zero GC overhead
+* High concurrent thread-safe access
+* Pure Go implementation
+* Expiration support
+* Nearly LRU algorithm
+* Strictly limited memory usage
+* Come with a toy server that supports a few basic Redis commands with pipeline
+
+##Performance
+Here is the benchmark result compares to built-in map, `Set` performance is about 2x faster than built-in map, `Get` performance is about 1/2x slower than built-in map. Since it is single threaded benchmark, in multi-threaded environment, 
+FreeCache should be many times faster than single lock protected built-in map.
+
+    BenchmarkCacheSet        3000000               446 ns/op
+    BenchmarkMapSet          2000000               861 ns/op
+    BenchmarkCacheGet        3000000               517 ns/op
+    BenchmarkMapGet         10000000               212 ns/op
+
+##Example Usage
+```go
+cacheSize := 100 * 1024 * 1024
+cache := freecache.NewCache(cacheSize)
+debug.SetGCPercent(20)
+key := []byte("abc")
+val := []byte("def")
+expire := 60 // expire in 60 seconds
+cache.Set(key, val, expire)
+got, err := cache.Get(key)
+if err != nil {
+    fmt.Println(err)
+} else {
+    fmt.Println(string(got))
+}
+affected := cache.Del(key)
+fmt.Println("deleted key ", affected)
+fmt.Println("entry count ", cache.EntryCount())
+```
+
+##Notice
+* Recommended Go version is 1.4.
+* Memory is preallocated. 
+* If you allocate large amount of memory, you may need to set `debug.SetGCPercent()` 
+to a much lower percentage to get a normal GC frequency.
+
+##How it is done
+FreeCache avoids GC overhead by reducing the number of pointers.
+No matter how many entries stored in it, there are only 512 pointers.
+The data set is sharded into 256 segments by the hash value of the key.
+Each segment has only two pointers, one is the ring buffer that stores keys and values, 
+the other one is the index slice which used to lookup for an entry.
+Each segment has its own lock, so it supports high concurrent access.
+
+##TODO
+* Support dump to file and load from file.
+* Support resize cache size at runtime.
+
+##License
+The MIT License
diff --git a/vendor/github.com/coocood/freecache/cache.go b/vendor/github.com/coocood/freecache/cache.go
new file mode 100644
index 0000000000..086ddea514
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/cache.go
@@ -0,0 +1,135 @@
+package freecache
+
+import (
+	"sync"
+	"sync/atomic"
+
+	"github.com/spaolacci/murmur3"
+)
+
+type Cache struct {
+	locks     [256]sync.Mutex
+	segments  [256]segment
+	hitCount  int64
+	missCount int64
+}
+
+func hashFunc(data []byte) uint64 {
+	return murmur3.Sum64(data)
+}
+
+// The cache size will be set to 512KB at minimum.
+// If the size is set relatively large, you should call
+// `debug.SetGCPercent()`, set it to a much smaller value
+// to limit the memory consumption and GC pause time.
+func NewCache(size int) (cache *Cache) {
+	if size < 512*1024 {
+		size = 512 * 1024
+	}
+	cache = new(Cache)
+	for i := 0; i < 256; i++ {
+		cache.segments[i] = newSegment(size/256, i)
+	}
+	return
+}
+
+// If the key is larger than 65535 or value is larger than 1/1024 of the cache size,
+// the entry will not be written to the cache. expireSeconds <= 0 means no expire,
+// but it can be evicted when cache is full.
+func (cache *Cache) Set(key, value []byte, expireSeconds int) (err error) {
+	hashVal := hashFunc(key)
+	segId := hashVal & 255
+	cache.locks[segId].Lock()
+	err = cache.segments[segId].set(key, value, hashVal, expireSeconds)
+	cache.locks[segId].Unlock()
+	return
+}
+
+// Get the value or not found error.
+func (cache *Cache) Get(key []byte) (value []byte, err error) {
+	hashVal := hashFunc(key)
+	segId := hashVal & 255
+	cache.locks[segId].Lock()
+	value, err = cache.segments[segId].get(key, hashVal)
+	cache.locks[segId].Unlock()
+	if err == nil {
+		atomic.AddInt64(&cache.hitCount, 1)
+	} else {
+		atomic.AddInt64(&cache.missCount, 1)
+	}
+	return
+}
+
+func (cache *Cache) Del(key []byte) (affected bool) {
+	hashVal := hashFunc(key)
+	segId := hashVal & 255
+	cache.locks[segId].Lock()
+	affected = cache.segments[segId].del(key, hashVal)
+	cache.locks[segId].Unlock()
+	return
+}
+
+func (cache *Cache) EvacuateCount() (count int64) {
+	for i := 0; i < 256; i++ {
+		count += atomic.LoadInt64(&cache.segments[i].totalEvacuate)
+	}
+	return
+}
+
+func (cache *Cache) EntryCount() (entryCount int64) {
+	for i := 0; i < 256; i++ {
+		entryCount += atomic.LoadInt64(&cache.segments[i].entryCount)
+	}
+	return
+}
+
+// The average unix timestamp when a entry being accessed.
+// Entries have greater access time will be evacuated when it
+// is about to be overwritten by new value.
+func (cache *Cache) AverageAccessTime() int64 {
+	var entryCount, totalTime int64
+	for i := 0; i < 256; i++ {
+		totalTime += atomic.LoadInt64(&cache.segments[i].totalTime)
+		entryCount += atomic.LoadInt64(&cache.segments[i].totalCount)
+	}
+	if entryCount == 0 {
+		return 0
+	} else {
+		return totalTime / entryCount
+	}
+}
+
+func (cache *Cache) HitCount() int64 {
+	return atomic.LoadInt64(&cache.hitCount)
+}
+
+func (cache *Cache) LookupCount() int64 {
+	return atomic.LoadInt64(&cache.hitCount) + atomic.LoadInt64(&cache.missCount)
+}
+
+func (cache *Cache) HitRate() float64 {
+	lookupCount := cache.LookupCount()
+	if lookupCount == 0 {
+		return 0
+	} else {
+		return float64(cache.HitCount()) / float64(lookupCount)
+	}
+}
+
+func (cache *Cache) OverwriteCount() (overwriteCount int64) {
+	for i := 0; i < 256; i++ {
+		overwriteCount += atomic.LoadInt64(&cache.segments[i].overwrites)
+	}
+	return
+}
+
+func (cache *Cache) Clear() {
+	for i := 0; i < 256; i++ {
+		cache.locks[i].Lock()
+		newSeg := newSegment(len(cache.segments[i].rb.data), i)
+		cache.segments[i] = newSeg
+		cache.locks[i].Unlock()
+	}
+	atomic.StoreInt64(&cache.hitCount, 0)
+	atomic.StoreInt64(&cache.missCount, 0)
+}
diff --git a/vendor/github.com/coocood/freecache/cache_test.go b/vendor/github.com/coocood/freecache/cache_test.go
new file mode 100644
index 0000000000..90e771b7c1
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/cache_test.go
@@ -0,0 +1,249 @@
+package freecache
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/binary"
+	"fmt"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestFreeCache(t *testing.T) {
+	cache := NewCache(1024)
+	if cache.HitRate() != 0 {
+		t.Error("initial hit rate should be zero")
+	}
+	if cache.AverageAccessTime() != 0 {
+		t.Error("initial average access time should be zero")
+	}
+	key := []byte("abcd")
+	val := []byte("efghijkl")
+	err := cache.Set(key, val, 0)
+	if err != nil {
+		t.Error("err should be nil")
+	}
+	value, err := cache.Get(key)
+	if err != nil || !bytes.Equal(value, val) {
+		t.Error("value not equal")
+	}
+	affected := cache.Del(key)
+	if !affected {
+		t.Error("del should return affected true")
+	}
+	value, err = cache.Get(key)
+	if err != ErrNotFound {
+		t.Error("error should be ErrNotFound after being deleted")
+	}
+	affected = cache.Del(key)
+	if affected {
+		t.Error("del should not return affected true")
+	}
+
+	cache.Clear()
+	n := 5000
+	for i := 0; i < n; i++ {
+		keyStr := fmt.Sprintf("key%v", i)
+		valStr := strings.Repeat(keyStr, 10)
+		err = cache.Set([]byte(keyStr), []byte(valStr), 0)
+		if err != nil {
+			t.Error(err)
+		}
+	}
+	time.Sleep(time.Second)
+	for i := 1; i < n; i += 2 {
+		keyStr := fmt.Sprintf("key%v", i)
+		cache.Get([]byte(keyStr))
+	}
+
+	for i := 1; i < n; i += 8 {
+		keyStr := fmt.Sprintf("key%v", i)
+		cache.Del([]byte(keyStr))
+	}
+
+	for i := 0; i < n; i += 2 {
+		keyStr := fmt.Sprintf("key%v", i)
+		valStr := strings.Repeat(keyStr, 10)
+		err = cache.Set([]byte(keyStr), []byte(valStr), 0)
+		if err != nil {
+			t.Error(err)
+		}
+	}
+	for i := 1; i < n; i += 2 {
+		keyStr := fmt.Sprintf("key%v", i)
+		expectedValStr := strings.Repeat(keyStr, 10)
+		value, err = cache.Get([]byte(keyStr))
+		if err == nil {
+			if string(value) != expectedValStr {
+				t.Errorf("value is %v, expected %v", string(value), expectedValStr)
+			}
+		}
+	}
+
+	t.Logf("hit rate is %v, evacuates %v, entries %v, average time %v\n",
+		cache.HitRate(), cache.EvacuateCount(), cache.EntryCount(), cache.AverageAccessTime())
+}
+
+func TestOverwrite(t *testing.T) {
+	cache := NewCache(1024)
+	key := []byte("abcd")
+	var val []byte
+	cache.Set(key, val, 0)
+	val = []byte("efgh")
+	cache.Set(key, val, 0)
+	val = append(val, 'i')
+	cache.Set(key, val, 0)
+	if count := cache.OverwriteCount(); count != 0 {
+		t.Error("overwrite count is", count, "expected ", 0)
+	}
+	res, _ := cache.Get(key)
+	if string(res) != string(val) {
+		t.Error(string(res))
+	}
+	val = append(val, 'j')
+	cache.Set(key, val, 0)
+	res, _ = cache.Get(key)
+	if string(res) != string(val) {
+		t.Error(string(res), "aaa")
+	}
+	val = append(val, 'k')
+	cache.Set(key, val, 0)
+	res, _ = cache.Get(key)
+	if string(res) != "efghijk" {
+		t.Error(string(res))
+	}
+	val = append(val, 'l')
+	cache.Set(key, val, 0)
+	res, _ = cache.Get(key)
+	if string(res) != "efghijkl" {
+		t.Error(string(res))
+	}
+	val = append(val, 'm')
+	cache.Set(key, val, 0)
+	if count := cache.OverwriteCount(); count != 3 {
+		t.Error("overwrite count is", count, "expected ", 3)
+	}
+
+}
+
+func TestExpire(t *testing.T) {
+	cache := NewCache(1024)
+	key := []byte("abcd")
+	val := []byte("efgh")
+	err := cache.Set(key, val, 1)
+	if err != nil {
+		t.Error("err should be nil")
+	}
+	time.Sleep(time.Second)
+	val, err = cache.Get(key)
+	if err == nil {
+		t.Fatal("key should be expired", string(val))
+	}
+}
+
+func TestLargeEntry(t *testing.T) {
+	cacheSize := 512 * 1024
+	cache := NewCache(cacheSize)
+	key := make([]byte, 65536)
+	val := []byte("efgh")
+	err := cache.Set(key, val, 0)
+	if err != ErrLargeKey {
+		t.Error("large key should return ErrLargeKey")
+	}
+	val, err = cache.Get(key)
+	if val != nil {
+		t.Error("value should be nil when get a big key")
+	}
+	key = []byte("abcd")
+	maxValLen := cacheSize/1024 - ENTRY_HDR_SIZE - len(key)
+	val = make([]byte, maxValLen+1)
+	err = cache.Set(key, val, 0)
+	if err != ErrLargeEntry {
+		t.Error("err should be ErrLargeEntry", err)
+	}
+	val = make([]byte, maxValLen-2)
+	err = cache.Set(key, val, 0)
+	if err != nil {
+		t.Error(err)
+	}
+	val = append(val, 0)
+	err = cache.Set(key, val, 0)
+	if err != nil {
+		t.Error(err)
+	}
+	val = append(val, 0)
+	err = cache.Set(key, val, 0)
+	if err != nil {
+		t.Error(err)
+	}
+	if cache.OverwriteCount() != 1 {
+		t.Error("over write count should be one.")
+	}
+	val = append(val, 0)
+	err = cache.Set(key, val, 0)
+	if err != ErrLargeEntry {
+		t.Error("err should be ErrLargeEntry", err)
+	}
+}
+
+func BenchmarkCacheSet(b *testing.B) {
+	cache := NewCache(256 * 1024 * 1024)
+	var key [8]byte
+	for i := 0; i < b.N; i++ {
+		binary.LittleEndian.PutUint64(key[:], uint64(i))
+		cache.Set(key[:], make([]byte, 8), 0)
+	}
+}
+
+func BenchmarkMapSet(b *testing.B) {
+	m := make(map[string][]byte)
+	var key [8]byte
+	for i := 0; i < b.N; i++ {
+		binary.LittleEndian.PutUint64(key[:], uint64(i))
+		m[string(key[:])] = make([]byte, 8)
+	}
+}
+
+func BenchmarkCacheGet(b *testing.B) {
+	b.StopTimer()
+	cache := NewCache(256 * 1024 * 1024)
+	var key [8]byte
+	for i := 0; i < b.N; i++ {
+		binary.LittleEndian.PutUint64(key[:], uint64(i))
+		cache.Set(key[:], make([]byte, 8), 0)
+	}
+	b.StartTimer()
+	for i := 0; i < b.N; i++ {
+		binary.LittleEndian.PutUint64(key[:], uint64(i))
+		cache.Get(key[:])
+	}
+}
+
+func BenchmarkMapGet(b *testing.B) {
+	b.StopTimer()
+	m := make(map[string][]byte)
+	var key [8]byte
+	for i := 0; i < b.N; i++ {
+		binary.LittleEndian.PutUint64(key[:], uint64(i))
+		m[string(key[:])] = make([]byte, 8)
+	}
+	b.StartTimer()
+	var hitCount int64
+	for i := 0; i < b.N; i++ {
+		binary.LittleEndian.PutUint64(key[:], uint64(i))
+		if m[string(key[:])] != nil {
+			hitCount++
+		}
+	}
+}
+
+func BenchmarkHashFunc(b *testing.B) {
+	key := make([]byte, 8)
+	rand.Read(key)
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		hashFunc(key)
+	}
+}
diff --git a/vendor/github.com/coocood/freecache/ringbuf.go b/vendor/github.com/coocood/freecache/ringbuf.go
new file mode 100644
index 0000000000..b4e2632ce4
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/ringbuf.go
@@ -0,0 +1,243 @@
+package freecache
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"io"
+)
+
+var ErrOutOfRange = errors.New("out of range")
+
+// Ring buffer has a fixed size, when data exceeds the
+// size, old data will be overwritten by new data.
+// It only contains the data in the stream from begin to end
+type RingBuf struct {
+	begin int64 // beginning offset of the data stream.
+	end   int64 // ending offset of the data stream.
+	data  []byte
+	index int //range from '0' to 'len(rb.data)-1'
+}
+
+func NewRingBuf(size int, begin int64) (rb RingBuf) {
+	rb.data = make([]byte, size)
+	rb.begin = begin
+	rb.end = begin
+	rb.index = 0
+	return
+}
+
+// Create a copy of the buffer.
+func (rb *RingBuf) Dump() []byte {
+	dump := make([]byte, len(rb.data))
+	copy(dump, rb.data)
+	return dump
+}
+
+func (rb *RingBuf) String() string {
+	return fmt.Sprintf("[size:%v, start:%v, end:%v, index:%v]", len(rb.data), rb.begin, rb.end, rb.index)
+}
+
+func (rb *RingBuf) Size() int64 {
+	return int64(len(rb.data))
+}
+
+func (rb *RingBuf) Begin() int64 {
+	return rb.begin
+}
+
+func (rb *RingBuf) End() int64 {
+	return rb.end
+}
+
+// read up to len(p), at off of the data stream.
+func (rb *RingBuf) ReadAt(p []byte, off int64) (n int, err error) {
+	if off > rb.end || off < rb.begin {
+		err = ErrOutOfRange
+		return
+	}
+	var readOff int
+	if rb.end-rb.begin < int64(len(rb.data)) {
+		readOff = int(off - rb.begin)
+	} else {
+		readOff = rb.index + int(off-rb.begin)
+	}
+	if readOff >= len(rb.data) {
+		readOff -= len(rb.data)
+	}
+	readEnd := readOff + int(rb.end-off)
+	if readEnd <= len(rb.data) {
+		n = copy(p, rb.data[readOff:readEnd])
+	} else {
+		n = copy(p, rb.data[readOff:])
+		if n < len(p) {
+			n += copy(p[n:], rb.data[:readEnd-len(rb.data)])
+		}
+	}
+	if n < len(p) {
+		err = io.EOF
+	}
+	return
+}
+
+func (rb *RingBuf) Write(p []byte) (n int, err error) {
+	if len(p) > len(rb.data) {
+		err = ErrOutOfRange
+		return
+	}
+	for n < len(p) {
+		written := copy(rb.data[rb.index:], p[n:])
+		rb.end += int64(written)
+		n += written
+		rb.index += written
+		if rb.index >= len(rb.data) {
+			rb.index -= len(rb.data)
+		}
+	}
+	if int(rb.end-rb.begin) > len(rb.data) {
+		rb.begin = rb.end - int64(len(rb.data))
+	}
+	return
+}
+
+func (rb *RingBuf) WriteAt(p []byte, off int64) (n int, err error) {
+	if off+int64(len(p)) > rb.end || off < rb.begin {
+		err = ErrOutOfRange
+		return
+	}
+	var writeOff int
+	if rb.end-rb.begin < int64(len(rb.data)) {
+		writeOff = int(off - rb.begin)
+	} else {
+		writeOff = rb.index + int(off-rb.begin)
+	}
+	if writeOff > len(rb.data) {
+		writeOff -= len(rb.data)
+	}
+	writeEnd := writeOff + int(rb.end-off)
+	if writeEnd <= len(rb.data) {
+		n = copy(rb.data[writeOff:writeEnd], p)
+	} else {
+		n = copy(rb.data[writeOff:], p)
+		if n < len(p) {
+			n += copy(rb.data[:writeEnd-len(rb.data)], p[n:])
+		}
+	}
+	return
+}
+
+func (rb *RingBuf) EqualAt(p []byte, off int64) bool {
+	if off+int64(len(p)) > rb.end || off < rb.begin {
+		return false
+	}
+	var readOff int
+	if rb.end-rb.begin < int64(len(rb.data)) {
+		readOff = int(off - rb.begin)
+	} else {
+		readOff = rb.index + int(off-rb.begin)
+	}
+	if readOff >= len(rb.data) {
+		readOff -= len(rb.data)
+	}
+	readEnd := readOff + len(p)
+	if readEnd <= len(rb.data) {
+		return bytes.Equal(p, rb.data[readOff:readEnd])
+	} else {
+		firstLen := len(rb.data) - readOff
+		equal := bytes.Equal(p[:firstLen], rb.data[readOff:])
+		if equal {
+			secondLen := len(p) - firstLen
+			equal = bytes.Equal(p[firstLen:], rb.data[:secondLen])
+		}
+		return equal
+	}
+}
+
+// Evacuate read the data at off, then write it to the the data stream,
+// Keep it from being overwritten by new data.
+func (rb *RingBuf) Evacuate(off int64, length int) (newOff int64) {
+	if off+int64(length) > rb.end || off < rb.begin {
+		return -1
+	}
+	var readOff int
+	if rb.end-rb.begin < int64(len(rb.data)) {
+		readOff = int(off - rb.begin)
+	} else {
+		readOff = rb.index + int(off-rb.begin)
+	}
+	if readOff >= len(rb.data) {
+		readOff -= len(rb.data)
+	}
+
+	if readOff == rb.index {
+		// no copy evacuate
+		rb.index += length
+		if rb.index >= len(rb.data) {
+			rb.index -= len(rb.data)
+		}
+	} else if readOff < rb.index {
+		var n = copy(rb.data[rb.index:], rb.data[readOff:readOff+length])
+		rb.index += n
+		if rb.index == len(rb.data) {
+			rb.index = copy(rb.data, rb.data[readOff+n:readOff+length])
+		}
+	} else {
+		var readEnd = readOff + length
+		var n int
+		if readEnd <= len(rb.data) {
+			n = copy(rb.data[rb.index:], rb.data[readOff:readEnd])
+			rb.index += n
+			if rb.index == len(rb.data) {
+				rb.index = copy(rb.data, rb.data[readOff+n:readEnd])
+			}
+		} else {
+			n = copy(rb.data[rb.index:], rb.data[readOff:])
+			rb.index += n
+			var tail = length - n
+			n = copy(rb.data[rb.index:], rb.data[:tail])
+			rb.index += n
+			if rb.index == len(rb.data) {
+				rb.index = copy(rb.data, rb.data[n:tail])
+			}
+		}
+	}
+	newOff = rb.end
+	rb.end += int64(length)
+	if rb.begin < rb.end-int64(len(rb.data)) {
+		rb.begin = rb.end - int64(len(rb.data))
+	}
+	return
+}
+
+func (rb *RingBuf) Resize(newSize int) {
+	if len(rb.data) == newSize {
+		return
+	}
+	newData := make([]byte, newSize)
+	var offset int
+	if rb.end-rb.begin == int64(len(rb.data)) {
+		offset = rb.index
+	}
+	if int(rb.end-rb.begin) > newSize {
+		discard := int(rb.end-rb.begin) - newSize
+		offset = (offset + discard) % len(rb.data)
+		rb.begin = rb.end - int64(newSize)
+	}
+	n := copy(newData, rb.data[offset:])
+	if n < newSize {
+		copy(newData[n:], rb.data[:offset])
+	}
+	rb.data = newData
+	rb.index = 0
+}
+
+func (rb *RingBuf) Skip(length int64) {
+	rb.end += length
+	rb.index += int(length)
+	for rb.index >= len(rb.data) {
+		rb.index -= len(rb.data)
+	}
+	if int(rb.end-rb.begin) > len(rb.data) {
+		rb.begin = rb.end - int64(len(rb.data))
+	}
+}
diff --git a/vendor/github.com/coocood/freecache/ringbuf_test.go b/vendor/github.com/coocood/freecache/ringbuf_test.go
new file mode 100644
index 0000000000..0e7f7e81ee
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/ringbuf_test.go
@@ -0,0 +1,35 @@
+package freecache
+
+import (
+	"testing"
+)
+
+func TestRingBuf(t *testing.T) {
+	rb := NewRingBuf(16, 0)
+	rb.Write([]byte("fghibbbbccccddde"))
+	rb.Write([]byte("fghibbbbc"))
+	rb.Resize(16)
+	off := rb.Evacuate(9, 3)
+	t.Log(string(rb.Dump()))
+	if off != rb.End()-3 {
+		t.Log(string(rb.Dump()), rb.End())
+		t.Fatalf("off got %v", off)
+	}
+	off = rb.Evacuate(15, 5)
+	t.Log(string(rb.Dump()))
+	if off != rb.End()-5 {
+		t.Fatalf("off got %v", off)
+	}
+	rb.Resize(64)
+	rb.Resize(32)
+	data := make([]byte, 5)
+	rb.ReadAt(data, off)
+	if string(data) != "efghi" {
+		t.Fatalf("read at should be efghi, got %v", string(data))
+	}
+
+	off = rb.Evacuate(0, 10)
+	if off != -1 {
+		t.Fatal("evacutate out of range offset should return error")
+	}
+}
diff --git a/vendor/github.com/coocood/freecache/segment.go b/vendor/github.com/coocood/freecache/segment.go
new file mode 100644
index 0000000000..6ea89b69f7
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/segment.go
@@ -0,0 +1,326 @@
+package freecache
+
+import (
+	"errors"
+	"time"
+	"unsafe"
+)
+
+const HASH_ENTRY_SIZE = 16
+const ENTRY_HDR_SIZE = 24
+
+var ErrLargeKey = errors.New("The key is larger than 65535")
+var ErrLargeEntry = errors.New("The entry size is larger than 1/1024 of cache size")
+var ErrNotFound = errors.New("Entry not found")
+
+// entry pointer struct points to an entry in ring buffer
+type entryPtr struct {
+	offset   int64  // entry offset in ring buffer
+	hash16   uint16 // entries are ordered by hash16 in a slot.
+	keyLen   uint16 // used to compare a key
+	reserved uint32
+}
+
+// entry header struct in ring buffer, followed by key and value.
+type entryHdr struct {
+	accessTime uint32
+	expireAt   uint32
+	keyLen     uint16
+	hash16     uint16
+	valLen     uint32
+	valCap     uint32
+	deleted    bool
+	slotId     uint8
+	reserved   uint16
+}
+
+// a segment contains 256 slots, a slot is an array of entry pointers ordered by hash16 value
+// the entry can be looked up by hash value of the key.
+type segment struct {
+	rb            RingBuf // ring buffer that stores data
+	segId         int
+	entryCount    int64
+	totalCount    int64      // number of entries in ring buffer, including deleted entries.
+	totalTime     int64      // used to calculate least recent used entry.
+	totalEvacuate int64      // used for debug
+	overwrites    int64      // used for debug
+	vacuumLen     int64      // up to vacuumLen, new data can be written without overwriting old data.
+	slotLens      [256]int32 // The actual length for every slot.
+	slotCap       int32      // max number of entry pointers a slot can hold.
+	slotsData     []entryPtr // shared by all 256 slots
+}
+
+func newSegment(bufSize int, segId int) (seg segment) {
+	seg.rb = NewRingBuf(bufSize, 0)
+	seg.segId = segId
+	seg.vacuumLen = int64(bufSize)
+	seg.slotCap = 1
+	seg.slotsData = make([]entryPtr, 256*seg.slotCap)
+	return
+}
+
+func (seg *segment) set(key, value []byte, hashVal uint64, expireSeconds int) (err error) {
+	if len(key) > 65535 {
+		return ErrLargeKey
+	}
+	maxKeyValLen := len(seg.rb.data)/4 - ENTRY_HDR_SIZE
+	if len(key)+len(value) > maxKeyValLen {
+		// Do not accept large entry.
+		return ErrLargeEntry
+	}
+	now := uint32(time.Now().Unix())
+	expireAt := uint32(0)
+	if expireSeconds > 0 {
+		expireAt = now + uint32(expireSeconds)
+	}
+
+	slotId := uint8(hashVal >> 8)
+	hash16 := uint16(hashVal >> 16)
+
+	var hdrBuf [ENTRY_HDR_SIZE]byte
+	hdr := (*entryHdr)(unsafe.Pointer(&hdrBuf[0]))
+
+	slotOff := int32(slotId) * seg.slotCap
+	slot := seg.slotsData[slotOff : slotOff+seg.slotLens[slotId] : slotOff+seg.slotCap]
+	idx, match := seg.lookup(slot, hash16, key)
+	if match {
+		matchedPtr := &slot[idx]
+		seg.rb.ReadAt(hdrBuf[:], matchedPtr.offset)
+		hdr.slotId = slotId
+		hdr.hash16 = hash16
+		hdr.keyLen = uint16(len(key))
+		hdr.accessTime = now
+		hdr.expireAt = expireAt
+		hdr.valLen = uint32(len(value))
+		if hdr.valCap >= hdr.valLen {
+			//in place overwrite
+			seg.totalTime += int64(hdr.accessTime) - int64(now)
+			seg.rb.WriteAt(hdrBuf[:], matchedPtr.offset)
+			seg.rb.WriteAt(value, matchedPtr.offset+ENTRY_HDR_SIZE+int64(hdr.keyLen))
+			seg.overwrites++
+			return
+		}
+		// increase capacity and limit entry len.
+		for hdr.valCap < hdr.valLen {
+			hdr.valCap *= 2
+		}
+		if hdr.valCap > uint32(maxKeyValLen-len(key)) {
+			hdr.valCap = uint32(maxKeyValLen - len(key))
+		}
+	} else {
+		hdr.slotId = slotId
+		hdr.hash16 = hash16
+		hdr.keyLen = uint16(len(key))
+		hdr.accessTime = now
+		hdr.expireAt = expireAt
+		hdr.valLen = uint32(len(value))
+		hdr.valCap = uint32(len(value))
+		if hdr.valCap == 0 { // avoid infinite loop when increasing capacity.
+			hdr.valCap = 1
+		}
+	}
+
+	entryLen := ENTRY_HDR_SIZE + int64(len(key)) + int64(hdr.valCap)
+	slotModified := seg.evacuate(entryLen, slotId, now)
+	if slotModified {
+		// the slot has been modified during evacuation, we need to looked up for the 'idx' again.
+		// otherwise there would be index out of bound error.
+		slot = seg.slotsData[slotOff : slotOff+seg.slotLens[slotId] : slotOff+seg.slotCap]
+		idx, match = seg.lookup(slot, hash16, key)
+	}
+	newOff := seg.rb.End()
+	if match {
+		seg.updateEntryPtr(slotId, hash16, slot[idx].offset, newOff)
+	} else {
+		seg.insertEntryPtr(slotId, hash16, newOff, idx, hdr.keyLen)
+	}
+	seg.rb.Write(hdrBuf[:])
+	seg.rb.Write(key)
+	seg.rb.Write(value)
+	seg.rb.Skip(int64(hdr.valCap - hdr.valLen))
+	seg.totalTime += int64(now)
+	seg.totalCount++
+	seg.vacuumLen -= entryLen
+	return
+}
+
+func (seg *segment) evacuate(entryLen int64, slotId uint8, now uint32) (slotModified bool) {
+	var oldHdrBuf [ENTRY_HDR_SIZE]byte
+	consecutiveEvacuate := 0
+	for seg.vacuumLen < entryLen {
+		oldOff := seg.rb.End() + seg.vacuumLen - seg.rb.Size()
+		seg.rb.ReadAt(oldHdrBuf[:], oldOff)
+		oldHdr := (*entryHdr)(unsafe.Pointer(&oldHdrBuf[0]))
+		oldEntryLen := ENTRY_HDR_SIZE + int64(oldHdr.keyLen) + int64(oldHdr.valCap)
+		if oldHdr.deleted {
+			consecutiveEvacuate = 0
+			seg.totalTime -= int64(oldHdr.accessTime)
+			seg.totalCount--
+			seg.vacuumLen += oldEntryLen
+			continue
+		}
+		expired := oldHdr.expireAt != 0 && oldHdr.expireAt < now
+		leastRecentUsed := int64(oldHdr.accessTime)*seg.totalCount <= seg.totalTime
+		if expired || leastRecentUsed || consecutiveEvacuate > 5 {
+			seg.delEntryPtr(oldHdr.slotId, oldHdr.hash16, oldOff)
+			if oldHdr.slotId == slotId {
+				slotModified = true
+			}
+			consecutiveEvacuate = 0
+			seg.totalTime -= int64(oldHdr.accessTime)
+			seg.totalCount--
+			seg.vacuumLen += oldEntryLen
+		} else {
+			// evacuate an old entry that has been accessed recently for better cache hit rate.
+			newOff := seg.rb.Evacuate(oldOff, int(oldEntryLen))
+			seg.updateEntryPtr(oldHdr.slotId, oldHdr.hash16, oldOff, newOff)
+			consecutiveEvacuate++
+			seg.totalEvacuate++
+		}
+	}
+	return
+}
+
+func (seg *segment) get(key []byte, hashVal uint64) (value []byte, err error) {
+	slotId := uint8(hashVal >> 8)
+	hash16 := uint16(hashVal >> 16)
+	slotOff := int32(slotId) * seg.slotCap
+	var slot = seg.slotsData[slotOff : slotOff+seg.slotLens[slotId] : slotOff+seg.slotCap]
+	idx, match := seg.lookup(slot, hash16, key)
+	if !match {
+		err = ErrNotFound
+		return
+	}
+	ptr := &slot[idx]
+	now := uint32(time.Now().Unix())
+
+	var hdrBuf [ENTRY_HDR_SIZE]byte
+	seg.rb.ReadAt(hdrBuf[:], ptr.offset)
+	hdr := (*entryHdr)(unsafe.Pointer(&hdrBuf[0]))
+
+	if hdr.expireAt != 0 && hdr.expireAt <= now {
+		seg.delEntryPtr(slotId, hash16, ptr.offset)
+		err = ErrNotFound
+		return
+	}
+	seg.totalTime += int64(now - hdr.accessTime)
+	hdr.accessTime = now
+	seg.rb.WriteAt(hdrBuf[:], ptr.offset)
+	value = make([]byte, hdr.valLen)
+
+	seg.rb.ReadAt(value, ptr.offset+ENTRY_HDR_SIZE+int64(hdr.keyLen))
+	return
+}
+
+func (seg *segment) del(key []byte, hashVal uint64) (affected bool) {
+	slotId := uint8(hashVal >> 8)
+	hash16 := uint16(hashVal >> 16)
+	slotOff := int32(slotId) * seg.slotCap
+	slot := seg.slotsData[slotOff : slotOff+seg.slotLens[slotId] : slotOff+seg.slotCap]
+	idx, match := seg.lookup(slot, hash16, key)
+	if !match {
+		return false
+	}
+	ptr := &slot[idx]
+	seg.delEntryPtr(slotId, hash16, ptr.offset)
+	return true
+}
+
+func (seg *segment) expand() {
+	newSlotData := make([]entryPtr, seg.slotCap*2*256)
+	for i := 0; i < 256; i++ {
+		off := int32(i) * seg.slotCap
+		copy(newSlotData[off*2:], seg.slotsData[off:off+seg.slotLens[i]])
+	}
+	seg.slotCap *= 2
+	seg.slotsData = newSlotData
+}
+
+func (seg *segment) updateEntryPtr(slotId uint8, hash16 uint16, oldOff, newOff int64) {
+	slotOff := int32(slotId) * seg.slotCap
+	slot := seg.slotsData[slotOff : slotOff+seg.slotLens[slotId] : slotOff+seg.slotCap]
+	idx, match := seg.lookupByOff(slot, hash16, oldOff)
+	if !match {
+		return
+	}
+	ptr := &slot[idx]
+	ptr.offset = newOff
+}
+
+func (seg *segment) insertEntryPtr(slotId uint8, hash16 uint16, offset int64, idx int, keyLen uint16) {
+	slotOff := int32(slotId) * seg.slotCap
+	if seg.slotLens[slotId] == seg.slotCap {
+		seg.expand()
+		slotOff *= 2
+	}
+	seg.slotLens[slotId]++
+	seg.entryCount++
+	slot := seg.slotsData[slotOff : slotOff+seg.slotLens[slotId] : slotOff+seg.slotCap]
+	copy(slot[idx+1:], slot[idx:])
+	slot[idx].offset = offset
+	slot[idx].hash16 = hash16
+	slot[idx].keyLen = keyLen
+}
+
+func (seg *segment) delEntryPtr(slotId uint8, hash16 uint16, offset int64) {
+	slotOff := int32(slotId) * seg.slotCap
+	slot := seg.slotsData[slotOff : slotOff+seg.slotLens[slotId] : slotOff+seg.slotCap]
+	idx, match := seg.lookupByOff(slot, hash16, offset)
+	if !match {
+		return
+	}
+	var entryHdrBuf [ENTRY_HDR_SIZE]byte
+	seg.rb.ReadAt(entryHdrBuf[:], offset)
+	entryHdr := (*entryHdr)(unsafe.Pointer(&entryHdrBuf[0]))
+	entryHdr.deleted = true
+	seg.rb.WriteAt(entryHdrBuf[:], offset)
+	copy(slot[idx:], slot[idx+1:])
+	seg.slotLens[slotId]--
+	seg.entryCount--
+}
+
+func entryPtrIdx(slot []entryPtr, hash16 uint16) (idx int) {
+	high := len(slot)
+	for idx < high {
+		mid := (idx + high) >> 1
+		oldEntry := &slot[mid]
+		if oldEntry.hash16 < hash16 {
+			idx = mid + 1
+		} else {
+			high = mid
+		}
+	}
+	return
+}
+
+func (seg *segment) lookup(slot []entryPtr, hash16 uint16, key []byte) (idx int, match bool) {
+	idx = entryPtrIdx(slot, hash16)
+	for idx < len(slot) {
+		ptr := &slot[idx]
+		if ptr.hash16 != hash16 {
+			break
+		}
+		match = int(ptr.keyLen) == len(key) && seg.rb.EqualAt(key, ptr.offset+ENTRY_HDR_SIZE)
+		if match {
+			return
+		}
+		idx++
+	}
+	return
+}
+
+func (seg *segment) lookupByOff(slot []entryPtr, hash16 uint16, offset int64) (idx int, match bool) {
+	idx = entryPtrIdx(slot, hash16)
+	for idx < len(slot) {
+		ptr := &slot[idx]
+		if ptr.hash16 != hash16 {
+			break
+		}
+		match = ptr.offset == offset
+		if match {
+			return
+		}
+		idx++
+	}
+	return
+}
diff --git a/vendor/github.com/coocood/freecache/server/main.go b/vendor/github.com/coocood/freecache/server/main.go
new file mode 100644
index 0000000000..43abb61ef5
--- /dev/null
+++ b/vendor/github.com/coocood/freecache/server/main.go
@@ -0,0 +1,318 @@
+//A basic freecache server supports redis protocol
+package main
+
+import (
+	"bufio"
+	"bytes"
+	"errors"
+	"github.com/coocood/freecache"
+	"io"
+	"log"
+	"net"
+	"runtime"
+	"strconv"
+	"time"
+	"runtime/debug"
+	_ "net/http/pprof"
+	"net/http"
+)
+
+var (
+	protocolErr       = errors.New("protocol error")
+	CRLF              = []byte("\r\n")
+	PING              = []byte("ping")
+	DBSIZE            = []byte("dbsize")
+	ERROR_UNSUPPORTED = []byte("-ERR unsupported command\r\n")
+	OK                = []byte("+OK\r\n")
+	PONG              = []byte("+PONG\r\n")
+	GET               = []byte("get")
+	SET               = []byte("set")
+	SETEX             = []byte("setex")
+	DEL               = []byte("del")
+	NIL               = []byte("$-1\r\n")
+	CZERO             = []byte(":0\r\n")
+	CONE              = []byte(":1\r\n")
+	BulkSign          = []byte("$")
+)
+
+type Request struct {
+	args [][]byte
+	buf  *bytes.Buffer
+}
+
+func (req *Request) Reset() {
+	req.args = req.args[:0]
+	req.buf.Reset()
+}
+
+type operation struct {
+	req       Request
+	replyChan chan *bytes.Buffer
+}
+
+type Session struct {
+	server    *Server
+	conn      net.Conn
+	addr      string
+	reader    *bufio.Reader
+	replyChan chan *bytes.Buffer
+}
+
+type Server struct {
+	cache       *freecache.Cache
+}
+
+func NewServer(cacheSize int) (server *Server) {
+	server = new(Server)
+	server.cache = freecache.NewCache(cacheSize)
+	return
+}
+
+func (server *Server) Start(addr string) error {
+	l, err := net.Listen("tcp", addr)
+	if err != nil {
+		log.Println(err)
+		return err
+	}
+	defer l.Close()
+	log.Println("Listening on port", addr)
+	for {
+		tcpListener := l.(*net.TCPListener)
+		tcpListener.SetDeadline(time.Now().Add(time.Second))
+		conn, err := l.Accept()
+		if err != nil {
+			if ne, ok := err.(net.Error); ok && ne.Temporary() {
+				continue
+			}
+			return err
+		}
+
+		session := new(Session)
+		session.conn = conn
+		session.replyChan = make(chan *bytes.Buffer, 100)
+		session.addr = conn.RemoteAddr().String()
+		session.server = server
+		session.reader = bufio.NewReader(conn)
+		go session.readLoop()
+		go session.writeLoop()
+	}
+}
+
+func copyN(buffer *bytes.Buffer, r *bufio.Reader, n int64) (err error) {
+	if n <= 512 {
+		var buf [512]byte
+		_, err = r.Read(buf[:n])
+		if err != nil {
+			return
+		}
+		buffer.Write(buf[:n])
+	} else {
+		_, err = io.CopyN(buffer, r, n)
+	}
+	return
+}
+
+func (server *Server) ReadClient(r *bufio.Reader, req *Request) (err error) {
+	line, err := readLine(r)
+	if err != nil {
+		return
+	}
+	if len(line) == 0 || line[0] != '*' {
+		err = protocolErr
+		return
+	}
+	argc, err := btoi(line[1:])
+	if err != nil {
+		return
+	}
+	if argc <= 0 || argc > 4 {
+		err = protocolErr
+		return
+	}
+	var argStarts [4]int
+	var argEnds [4]int
+	req.buf.Write(line)
+	req.buf.Write(CRLF)
+	cursor := len(line) + 2
+	for i := 0; i < argc; i++ {
+		line, err = readLine(r)
+		if err != nil {
+			return
+		}
+		if len(line) == 0 || line[0] != '$' {
+			err = protocolErr
+			return
+		}
+		var argLen int
+		argLen, err = btoi(line[1:])
+		if err != nil {
+			return
+		}
+		if argLen < 0 || argLen > 512*1024*1024 {
+			err = protocolErr
+			return
+		}
+		req.buf.Write(line)
+		req.buf.Write(CRLF)
+		cursor += len(line) + 2
+		err = copyN(req.buf, r, int64(argLen)+2)
+		if err != nil {
+			return
+		}
+		argStarts[i] = cursor
+		argEnds[i] = cursor + argLen
+		cursor += argLen + 2
+	}
+	data := req.buf.Bytes()
+	for i := 0; i < argc; i++ {
+		req.args = append(req.args, data[argStarts[i]:argEnds[i]])
+	}
+	lower(req.args[0])
+	return
+}
+
+func (down *Session) readLoop() {
+	var req = new(Request)
+	req.buf = new(bytes.Buffer)
+	for {
+		req.Reset()
+		err := down.server.ReadClient(down.reader, req)
+		if err != nil {
+			close(down.replyChan)
+			return
+		}
+		reply := new(bytes.Buffer)
+		if len(req.args) == 4 && bytes.Equal(req.args[0], SETEX) {
+			expire, err := btoi(req.args[2])
+			if err != nil {
+				reply.Write(ERROR_UNSUPPORTED)
+			} else {
+				down.server.cache.Set(req.args[1], req.args[3], expire)
+				reply.Write(OK)
+			}
+		} else if len(req.args) == 3 && bytes.Equal(req.args[0], SET) {
+			down.server.cache.Set(req.args[1], req.args[2], 0)
+			reply.Write(OK)
+		} else if len(req.args) == 2 {
+			if bytes.Equal(req.args[0], GET) {
+				value, err := down.server.cache.Get(req.args[1])
+				if err != nil {
+					reply.Write(NIL)
+				} else {
+					bukLen := strconv.Itoa(len(value))
+					reply.Write(BulkSign)
+					reply.WriteString(bukLen)
+					reply.Write(CRLF)
+					reply.Write(value)
+					reply.Write(CRLF)
+				}
+			} else if bytes.Equal(req.args[0], DEL) {
+				if down.server.cache.Del(req.args[1]) {
+					reply.Write(CONE)
+				} else {
+					reply.Write(CZERO)
+				}
+			}
+		} else if len(req.args) == 1 {
+			if bytes.Equal(req.args[0], PING) {
+				reply.Write(PONG)
+			} else if bytes.Equal(req.args[0], DBSIZE) {
+				entryCount := down.server.cache.EntryCount()
+				reply.WriteString(":")
+				reply.WriteString(strconv.Itoa(int(entryCount)))
+				reply.Write(CRLF)
+			} else {
+				reply.Write(ERROR_UNSUPPORTED)
+			}
+		}
+		down.replyChan <- reply
+	}
+}
+
+func (down *Session) writeLoop() {
+	var buffer = bytes.NewBuffer(nil)
+	var replies = make([]*bytes.Buffer, 1)
+	for {
+		buffer.Reset()
+		select {
+		case reply, ok := <-down.replyChan:
+			if !ok {
+				down.conn.Close()
+				return
+			}
+			replies = replies[:1]
+			replies[0] = reply
+			queueLen := len(down.replyChan)
+			for i := 0; i < queueLen; i++ {
+				reply = <-down.replyChan
+				replies = append(replies, reply)
+			}
+			for _, reply := range replies {
+				if reply == nil {
+					buffer.Write(NIL)
+					continue
+				}
+				buffer.Write(reply.Bytes())
+			}
+			_, err := down.conn.Write(buffer.Bytes())
+			if err != nil {
+				down.conn.Close()
+				return
+			}
+		}
+	}
+}
+
+func readLine(r *bufio.Reader) ([]byte, error) {
+	p, err := r.ReadSlice('\n')
+	if err != nil {
+		return nil, err
+	}
+	i := len(p) - 2
+	if i < 0 || p[i] != '\r' {
+		return nil, protocolErr
+	}
+	return p[:i], nil
+}
+
+func btoi(data []byte) (int, error) {
+	if len(data) == 0 {
+		return 0, nil
+	}
+	i := 0
+	sign := 1
+	if data[0] == '-' {
+		i++
+		sign *= -1
+	}
+	if i >= len(data) {
+		return 0, protocolErr
+	}
+	var l int
+	for ; i < len(data); i++ {
+		c := data[i]
+		if c < '0' || c > '9' {
+			return 0, protocolErr
+		}
+		l = l*10 + int(c-'0')
+	}
+	return sign * l, nil
+}
+
+func lower(data []byte) {
+	for i := 0; i < len(data); i++ {
+		if data[i] >= 'A' && data[i] <= 'Z' {
+			data[i] += 'a' - 'A'
+		}
+	}
+}
+
+func main() {
+	runtime.GOMAXPROCS(runtime.NumCPU()-1)
+	server := NewServer(256 * 1024 * 1024)
+	debug.SetGCPercent(10)
+	go func() {
+		log.Println(http.ListenAndServe("localhost:6060", nil))
+	}()
+	server.Start(":7788")
+}
diff --git a/vendor/github.com/spaolacci/murmur3/LICENSE b/vendor/github.com/spaolacci/murmur3/LICENSE
new file mode 100644
index 0000000000..2a46fd7500
--- /dev/null
+++ b/vendor/github.com/spaolacci/murmur3/LICENSE
@@ -0,0 +1,24 @@
+Copyright 2013, Sébastien Paolacci.
+All rights reserved.
+
+Redistribution and use in source and binary forms, with or without
+modification, are permitted provided that the following conditions are met:
+    * Redistributions of source code must retain the above copyright
+      notice, this list of conditions and the following disclaimer.
+    * Redistributions in binary form must reproduce the above copyright
+      notice, this list of conditions and the following disclaimer in the
+      documentation and/or other materials provided with the distribution.
+    * Neither the name of the library nor the
+      names of its contributors may be used to endorse or promote products
+      derived from this software without specific prior written permission.
+
+THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
+ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
+DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
diff --git a/vendor/github.com/spaolacci/murmur3/README.md b/vendor/github.com/spaolacci/murmur3/README.md
new file mode 100644
index 0000000000..1edf62300d
--- /dev/null
+++ b/vendor/github.com/spaolacci/murmur3/README.md
@@ -0,0 +1,84 @@
+murmur3
+=======
+
+Native Go implementation of Austin Appleby's third MurmurHash revision (aka
+MurmurHash3).
+
+Reference algorithm has been slightly hacked as to support the streaming mode
+required by Go's standard [Hash interface](http://golang.org/pkg/hash/#Hash).
+
+
+Benchmarks
+----------
+
+Go tip as of 2014-06-12 (i.e almost go1.3), core i7 @ 3.4 Ghz. All runs
+include hasher instantiation and sequence finalization.
+
+<pre>
+
+Benchmark32_1        500000000     7.69 ns/op      130.00 MB/s
+Benchmark32_2        200000000     8.83 ns/op      226.42 MB/s
+Benchmark32_4        500000000     7.99 ns/op      500.39 MB/s
+Benchmark32_8        200000000     9.47 ns/op      844.69 MB/s
+Benchmark32_16       100000000     12.1 ns/op     1321.61 MB/s
+Benchmark32_32       100000000     18.3 ns/op     1743.93 MB/s
+Benchmark32_64        50000000     30.9 ns/op     2071.64 MB/s
+Benchmark32_128       50000000     57.6 ns/op     2222.96 MB/s
+Benchmark32_256       20000000      116 ns/op     2188.60 MB/s
+Benchmark32_512       10000000      226 ns/op     2260.59 MB/s
+Benchmark32_1024       5000000      452 ns/op     2263.73 MB/s
+Benchmark32_2048       2000000      891 ns/op     2296.02 MB/s
+Benchmark32_4096       1000000     1787 ns/op     2290.92 MB/s
+Benchmark32_8192        500000     3593 ns/op     2279.68 MB/s
+Benchmark128_1       100000000     26.1 ns/op       38.33 MB/s
+Benchmark128_2       100000000     29.0 ns/op       69.07 MB/s
+Benchmark128_4        50000000     29.8 ns/op      134.17 MB/s
+Benchmark128_8        50000000     31.6 ns/op      252.86 MB/s
+Benchmark128_16      100000000     26.5 ns/op      603.42 MB/s
+Benchmark128_32      100000000     28.6 ns/op     1117.15 MB/s
+Benchmark128_64       50000000     35.5 ns/op     1800.97 MB/s
+Benchmark128_128      50000000     50.9 ns/op     2515.50 MB/s
+Benchmark128_256      20000000     76.9 ns/op     3330.11 MB/s
+Benchmark128_512      20000000      135 ns/op     3769.09 MB/s
+Benchmark128_1024     10000000      250 ns/op     4094.38 MB/s
+Benchmark128_2048      5000000      477 ns/op     4290.75 MB/s
+Benchmark128_4096      2000000      940 ns/op     4353.29 MB/s
+Benchmark128_8192      1000000     1838 ns/op     4455.47 MB/s
+
+</pre>
+
+
+<pre>
+
+benchmark              Go1.0 MB/s    Go1.1 MB/s  speedup    Go1.2 MB/s  speedup    Go1.3 MB/s  speedup
+Benchmark32_1               98.90        118.59    1.20x        114.79    0.97x        130.00    1.13x
+Benchmark32_2              168.04        213.31    1.27x        210.65    0.99x        226.42    1.07x
+Benchmark32_4              414.01        494.19    1.19x        490.29    0.99x        500.39    1.02x
+Benchmark32_8              662.19        836.09    1.26x        836.46    1.00x        844.69    1.01x
+Benchmark32_16             917.46       1304.62    1.42x       1297.63    0.99x       1321.61    1.02x
+Benchmark32_32            1141.93       1737.54    1.52x       1728.24    0.99x       1743.93    1.01x
+Benchmark32_64            1289.47       2039.51    1.58x       2038.20    1.00x       2071.64    1.02x
+Benchmark32_128           1299.23       2097.63    1.61x       2177.13    1.04x       2222.96    1.02x
+Benchmark32_256           1369.90       2202.34    1.61x       2213.15    1.00x       2188.60    0.99x
+Benchmark32_512           1399.56       2255.72    1.61x       2264.49    1.00x       2260.59    1.00x
+Benchmark32_1024          1410.90       2285.82    1.62x       2270.99    0.99x       2263.73    1.00x
+Benchmark32_2048          1422.14       2297.62    1.62x       2269.59    0.99x       2296.02    1.01x
+Benchmark32_4096          1420.53       2307.81    1.62x       2273.43    0.99x       2290.92    1.01x
+Benchmark32_8192          1424.79       2312.87    1.62x       2286.07    0.99x       2279.68    1.00x
+Benchmark128_1               8.32         30.15    3.62x         30.84    1.02x         38.33    1.24x
+Benchmark128_2              16.38         59.72    3.65x         59.37    0.99x         69.07    1.16x
+Benchmark128_4              32.26        112.96    3.50x        114.24    1.01x        134.17    1.17x
+Benchmark128_8              62.68        217.88    3.48x        218.18    1.00x        252.86    1.16x
+Benchmark128_16            128.47        451.57    3.51x        474.65    1.05x        603.42    1.27x
+Benchmark128_32            246.18        910.42    3.70x        871.06    0.96x       1117.15    1.28x
+Benchmark128_64            449.05       1477.64    3.29x       1449.24    0.98x       1800.97    1.24x
+Benchmark128_128           762.61       2222.42    2.91x       2217.30    1.00x       2515.50    1.13x
+Benchmark128_256          1179.92       3005.46    2.55x       2931.55    0.98x       3330.11    1.14x
+Benchmark128_512          1616.51       3590.75    2.22x       3592.08    1.00x       3769.09    1.05x
+Benchmark128_1024         1964.36       3979.67    2.03x       4034.01    1.01x       4094.38    1.01x
+Benchmark128_2048         2225.07       4156.93    1.87x       4244.17    1.02x       4290.75    1.01x
+Benchmark128_4096         2360.15       4299.09    1.82x       4392.35    1.02x       4353.29    0.99x
+Benchmark128_8192         2411.50       4356.84    1.81x       4480.68    1.03x       4455.47    0.99x
+
+</pre>
+
diff --git a/vendor/github.com/spaolacci/murmur3/murmur.go b/vendor/github.com/spaolacci/murmur3/murmur.go
new file mode 100644
index 0000000000..f99557cc3e
--- /dev/null
+++ b/vendor/github.com/spaolacci/murmur3/murmur.go
@@ -0,0 +1,65 @@
+// Copyright 2013, Sébastien Paolacci. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+/*
+Native (and fast) implementation of Austin Appleby's MurmurHash3.
+
+Package murmur3 implements Austin Appleby's non-cryptographic MurmurHash3.
+
+ Reference implementation:
+    http://code.google.com/p/smhasher/wiki/MurmurHash3
+
+ History, characteristics and (legacy) perfs:
+    https://sites.google.com/site/murmurhash/
+    https://sites.google.com/site/murmurhash/statistics
+*/
+package murmur3
+
+type bmixer interface {
+	bmix(p []byte) (tail []byte)
+	Size() (n int)
+	reset()
+}
+
+type digest struct {
+	clen int      // Digested input cumulative length.
+	tail []byte   // 0 to Size()-1 bytes view of `buf'.
+	buf  [16]byte // Expected (but not required) to be Size() large.
+	bmixer
+}
+
+func (d *digest) BlockSize() int { return 1 }
+
+func (d *digest) Write(p []byte) (n int, err error) {
+	n = len(p)
+	d.clen += n
+
+	if len(d.tail) > 0 {
+		// Stick back pending bytes.
+		nfree := d.Size() - len(d.tail) // nfree ∈ [1, d.Size()-1].
+		if nfree < len(p) {
+			// One full block can be formed.
+			block := append(d.tail, p[:nfree]...)
+			p = p[nfree:]
+			_ = d.bmix(block) // No tail.
+		} else {
+			// Tail's buf is large enough to prevent reallocs.
+			p = append(d.tail, p...)
+		}
+	}
+
+	d.tail = d.bmix(p)
+
+	// Keep own copy of the 0 to Size()-1 pending bytes.
+	nn := copy(d.buf[:], d.tail)
+	d.tail = d.buf[:nn]
+
+	return n, nil
+}
+
+func (d *digest) Reset() {
+	d.clen = 0
+	d.tail = nil
+	d.bmixer.reset()
+}
diff --git a/vendor/github.com/spaolacci/murmur3/murmur128.go b/vendor/github.com/spaolacci/murmur3/murmur128.go
new file mode 100644
index 0000000000..d54d136541
--- /dev/null
+++ b/vendor/github.com/spaolacci/murmur3/murmur128.go
@@ -0,0 +1,189 @@
+package murmur3
+
+import (
+	//"encoding/binary"
+	"hash"
+	"unsafe"
+)
+
+const (
+	c1_128 = 0x87c37b91114253d5
+	c2_128 = 0x4cf5ad432745937f
+)
+
+// Make sure interfaces are correctly implemented.
+var (
+	_ hash.Hash = new(digest128)
+	_ Hash128   = new(digest128)
+	_ bmixer    = new(digest128)
+)
+
+// Hack: the standard api doesn't define any Hash128 interface.
+type Hash128 interface {
+	hash.Hash
+	Sum128() (uint64, uint64)
+}
+
+// digest128 represents a partial evaluation of a 128 bites hash.
+type digest128 struct {
+	digest
+	h1 uint64 // Unfinalized running hash part 1.
+	h2 uint64 // Unfinalized running hash part 2.
+}
+
+func New128() Hash128 {
+	d := new(digest128)
+	d.bmixer = d
+	d.Reset()
+	return d
+}
+
+func (d *digest128) Size() int { return 16 }
+
+func (d *digest128) reset() { d.h1, d.h2 = 0, 0 }
+
+func (d *digest128) Sum(b []byte) []byte {
+	h1, h2 := d.Sum128()
+	return append(b,
+		byte(h1>>56), byte(h1>>48), byte(h1>>40), byte(h1>>32),
+		byte(h1>>24), byte(h1>>16), byte(h1>>8), byte(h1),
+
+		byte(h2>>56), byte(h2>>48), byte(h2>>40), byte(h2>>32),
+		byte(h2>>24), byte(h2>>16), byte(h2>>8), byte(h2),
+	)
+}
+
+func (d *digest128) bmix(p []byte) (tail []byte) {
+	h1, h2 := d.h1, d.h2
+
+	nblocks := len(p) / 16
+	for i := 0; i < nblocks; i++ {
+		t := (*[2]uint64)(unsafe.Pointer(&p[i*16]))
+		k1, k2 := t[0], t[1]
+
+		k1 *= c1_128
+		k1 = (k1 << 31) | (k1 >> 33) // rotl64(k1, 31)
+		k1 *= c2_128
+		h1 ^= k1
+
+		h1 = (h1 << 27) | (h1 >> 37) // rotl64(h1, 27)
+		h1 += h2
+		h1 = h1*5 + 0x52dce729
+
+		k2 *= c2_128
+		k2 = (k2 << 33) | (k2 >> 31) // rotl64(k2, 33)
+		k2 *= c1_128
+		h2 ^= k2
+
+		h2 = (h2 << 31) | (h2 >> 33) // rotl64(h2, 31)
+		h2 += h1
+		h2 = h2*5 + 0x38495ab5
+	}
+	d.h1, d.h2 = h1, h2
+	return p[nblocks*d.Size():]
+}
+
+func (d *digest128) Sum128() (h1, h2 uint64) {
+
+	h1, h2 = d.h1, d.h2
+
+	var k1, k2 uint64
+	switch len(d.tail) & 15 {
+	case 15:
+		k2 ^= uint64(d.tail[14]) << 48
+		fallthrough
+	case 14:
+		k2 ^= uint64(d.tail[13]) << 40
+		fallthrough
+	case 13:
+		k2 ^= uint64(d.tail[12]) << 32
+		fallthrough
+	case 12:
+		k2 ^= uint64(d.tail[11]) << 24
+		fallthrough
+	case 11:
+		k2 ^= uint64(d.tail[10]) << 16
+		fallthrough
+	case 10:
+		k2 ^= uint64(d.tail[9]) << 8
+		fallthrough
+	case 9:
+		k2 ^= uint64(d.tail[8]) << 0
+
+		k2 *= c2_128
+		k2 = (k2 << 33) | (k2 >> 31) // rotl64(k2, 33)
+		k2 *= c1_128
+		h2 ^= k2
+
+		fallthrough
+
+	case 8:
+		k1 ^= uint64(d.tail[7]) << 56
+		fallthrough
+	case 7:
+		k1 ^= uint64(d.tail[6]) << 48
+		fallthrough
+	case 6:
+		k1 ^= uint64(d.tail[5]) << 40
+		fallthrough
+	case 5:
+		k1 ^= uint64(d.tail[4]) << 32
+		fallthrough
+	case 4:
+		k1 ^= uint64(d.tail[3]) << 24
+		fallthrough
+	case 3:
+		k1 ^= uint64(d.tail[2]) << 16
+		fallthrough
+	case 2:
+		k1 ^= uint64(d.tail[1]) << 8
+		fallthrough
+	case 1:
+		k1 ^= uint64(d.tail[0]) << 0
+		k1 *= c1_128
+		k1 = (k1 << 31) | (k1 >> 33) // rotl64(k1, 31)
+		k1 *= c2_128
+		h1 ^= k1
+	}
+
+	h1 ^= uint64(d.clen)
+	h2 ^= uint64(d.clen)
+
+	h1 += h2
+	h2 += h1
+
+	h1 = fmix64(h1)
+	h2 = fmix64(h2)
+
+	h1 += h2
+	h2 += h1
+
+	return h1, h2
+}
+
+func fmix64(k uint64) uint64 {
+	k ^= k >> 33
+	k *= 0xff51afd7ed558ccd
+	k ^= k >> 33
+	k *= 0xc4ceb9fe1a85ec53
+	k ^= k >> 33
+	return k
+}
+
+/*
+func rotl64(x uint64, r byte) uint64 {
+	return (x << r) | (x >> (64 - r))
+}
+*/
+
+// Sum128 returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New128()
+//     hasher.Write(data)
+//     return hasher.Sum128()
+func Sum128(data []byte) (h1 uint64, h2 uint64) {
+	d := &digest128{h1: 0, h2: 0}
+	d.tail = d.bmix(data)
+	d.clen = len(data)
+	return d.Sum128()
+}
diff --git a/vendor/github.com/spaolacci/murmur3/murmur32.go b/vendor/github.com/spaolacci/murmur3/murmur32.go
new file mode 100644
index 0000000000..8733f7cd76
--- /dev/null
+++ b/vendor/github.com/spaolacci/murmur3/murmur32.go
@@ -0,0 +1,154 @@
+package murmur3
+
+// http://code.google.com/p/guava-libraries/source/browse/guava/src/com/google/common/hash/Murmur3_32HashFunction.java
+
+import (
+	"hash"
+	"unsafe"
+)
+
+// Make sure interfaces are correctly implemented.
+var (
+	_ hash.Hash   = new(digest32)
+	_ hash.Hash32 = new(digest32)
+)
+
+const (
+	c1_32 uint32 = 0xcc9e2d51
+	c2_32 uint32 = 0x1b873593
+)
+
+// digest32 represents a partial evaluation of a 32 bites hash.
+type digest32 struct {
+	digest
+	h1 uint32 // Unfinalized running hash.
+}
+
+func New32() hash.Hash32 {
+	d := new(digest32)
+	d.bmixer = d
+	d.Reset()
+	return d
+}
+
+func (d *digest32) Size() int { return 4 }
+
+func (d *digest32) reset() { d.h1 = 0 }
+
+func (d *digest32) Sum(b []byte) []byte {
+	h := d.Sum32()
+	return append(b, byte(h>>24), byte(h>>16), byte(h>>8), byte(h))
+}
+
+// Digest as many blocks as possible.
+func (d *digest32) bmix(p []byte) (tail []byte) {
+	h1 := d.h1
+
+	nblocks := len(p) / 4
+	for i := 0; i < nblocks; i++ {
+		k1 := *(*uint32)(unsafe.Pointer(&p[i*4]))
+
+		k1 *= c1_32
+		k1 = (k1 << 15) | (k1 >> 17) // rotl32(k1, 15)
+		k1 *= c2_32
+
+		h1 ^= k1
+		h1 = (h1 << 13) | (h1 >> 19) // rotl32(h1, 13)
+		h1 = h1*5 + 0xe6546b64
+	}
+	d.h1 = h1
+	return p[nblocks*d.Size():]
+}
+
+func (d *digest32) Sum32() (h1 uint32) {
+
+	h1 = d.h1
+
+	var k1 uint32
+	switch len(d.tail) & 3 {
+	case 3:
+		k1 ^= uint32(d.tail[2]) << 16
+		fallthrough
+	case 2:
+		k1 ^= uint32(d.tail[1]) << 8
+		fallthrough
+	case 1:
+		k1 ^= uint32(d.tail[0])
+		k1 *= c1_32
+		k1 = (k1 << 15) | (k1 >> 17) // rotl32(k1, 15)
+		k1 *= c2_32
+		h1 ^= k1
+	}
+
+	h1 ^= uint32(d.clen)
+
+	h1 ^= h1 >> 16
+	h1 *= 0x85ebca6b
+	h1 ^= h1 >> 13
+	h1 *= 0xc2b2ae35
+	h1 ^= h1 >> 16
+
+	return h1
+}
+
+/*
+func rotl32(x uint32, r byte) uint32 {
+	return (x << r) | (x >> (32 - r))
+}
+*/
+
+// Sum32 returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New32()
+//     hasher.Write(data)
+//     return hasher.Sum32()
+func Sum32(data []byte) uint32 {
+
+	var h1 uint32 = 0
+
+	nblocks := len(data) / 4
+	var p uintptr
+	if len(data) > 0 {
+		p = uintptr(unsafe.Pointer(&data[0]))
+	}
+	p1 := p + uintptr(4*nblocks)
+	for ; p < p1; p += 4 {
+		k1 := *(*uint32)(unsafe.Pointer(p))
+
+		k1 *= c1_32
+		k1 = (k1 << 15) | (k1 >> 17) // rotl32(k1, 15)
+		k1 *= c2_32
+
+		h1 ^= k1
+		h1 = (h1 << 13) | (h1 >> 19) // rotl32(h1, 13)
+		h1 = h1*5 + 0xe6546b64
+	}
+
+	tail := data[nblocks*4:]
+
+	var k1 uint32
+	switch len(tail) & 3 {
+	case 3:
+		k1 ^= uint32(tail[2]) << 16
+		fallthrough
+	case 2:
+		k1 ^= uint32(tail[1]) << 8
+		fallthrough
+	case 1:
+		k1 ^= uint32(tail[0])
+		k1 *= c1_32
+		k1 = (k1 << 15) | (k1 >> 17) // rotl32(k1, 15)
+		k1 *= c2_32
+		h1 ^= k1
+	}
+
+	h1 ^= uint32(len(data))
+
+	h1 ^= h1 >> 16
+	h1 *= 0x85ebca6b
+	h1 ^= h1 >> 13
+	h1 *= 0xc2b2ae35
+	h1 ^= h1 >> 16
+
+	return h1
+}
diff --git a/vendor/github.com/spaolacci/murmur3/murmur64.go b/vendor/github.com/spaolacci/murmur3/murmur64.go
new file mode 100644
index 0000000000..6e43065fb8
--- /dev/null
+++ b/vendor/github.com/spaolacci/murmur3/murmur64.go
@@ -0,0 +1,45 @@
+package murmur3
+
+import (
+	"hash"
+)
+
+// Make sure interfaces are correctly implemented.
+var (
+	_ hash.Hash   = new(digest64)
+	_ hash.Hash64 = new(digest64)
+	_ bmixer      = new(digest64)
+)
+
+// digest64 is half a digest128.
+type digest64 digest128
+
+func New64() hash.Hash64 {
+	d := (*digest64)(New128().(*digest128))
+	return d
+}
+
+func (d *digest64) Sum(b []byte) []byte {
+	h1 := d.Sum64()
+	return append(b,
+		byte(h1>>56), byte(h1>>48), byte(h1>>40), byte(h1>>32),
+		byte(h1>>24), byte(h1>>16), byte(h1>>8), byte(h1))
+}
+
+func (d *digest64) Sum64() uint64 {
+	h1, _ := (*digest128)(d).Sum128()
+	return h1
+}
+
+// Sum64 returns the MurmurHash3 sum of data. It is equivalent to the
+// following sequence (without the extra burden and the extra allocation):
+//     hasher := New64()
+//     hasher.Write(data)
+//     return hasher.Sum64()
+func Sum64(data []byte) uint64 {
+	d := &digest128{h1: 0, h2: 0}
+	d.tail = d.bmix(data)
+	d.clen = len(data)
+	h1, _ := d.Sum128()
+	return h1
+}
diff --git a/vendor/github.com/spaolacci/murmur3/murmur_test.go b/vendor/github.com/spaolacci/murmur3/murmur_test.go
new file mode 100644
index 0000000000..bf1652acd3
--- /dev/null
+++ b/vendor/github.com/spaolacci/murmur3/murmur_test.go
@@ -0,0 +1,251 @@
+package murmur3
+
+import (
+	"fmt"
+	"hash"
+	"testing"
+)
+
+var data = []struct {
+	h32   uint32
+	h64_1 uint64
+	h64_2 uint64
+	s     string
+}{
+	{0x00000000, 0x0000000000000000, 0x0000000000000000, ""},
+	{0x248bfa47, 0xcbd8a7b341bd9b02, 0x5b1e906a48ae1d19, "hello"},
+	{0x149bbb7f, 0x342fac623a5ebc8e, 0x4cdcbc079642414d, "hello, world"},
+	{0xe31e8a70, 0xb89e5988b737affc, 0x664fc2950231b2cb, "19 Jan 2038 at 3:14:07 AM"},
+	{0xd5c48bfc, 0xcd99481f9ee902c9, 0x695da1a38987b6e7, "The quick brown fox jumps over the lazy dog."},
+}
+
+func TestRef(t *testing.T) {
+	for _, elem := range data {
+
+		var h32 hash.Hash32 = New32()
+		h32.Write([]byte(elem.s))
+		if v := h32.Sum32(); v != elem.h32 {
+			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h32)
+		}
+
+		var h32_byte hash.Hash32 = New32()
+		h32_byte.Write([]byte(elem.s))
+		target := fmt.Sprintf("%08x", elem.h32)
+		if p := fmt.Sprintf("%x", h32_byte.Sum(nil)); p != target {
+			t.Errorf("'%s': %s (want %s)", elem.s, p, target)
+		}
+
+		if v := Sum32([]byte(elem.s)); v != elem.h32 {
+			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h32)
+		}
+
+		var h64 hash.Hash64 = New64()
+		h64.Write([]byte(elem.s))
+		if v := h64.Sum64(); v != elem.h64_1 {
+			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h64_1)
+		}
+
+		var h64_byte hash.Hash64 = New64()
+		h64_byte.Write([]byte(elem.s))
+		target = fmt.Sprintf("%016x", elem.h64_1)
+		if p := fmt.Sprintf("%x", h64_byte.Sum(nil)); p != target {
+			t.Errorf("'%s': %s (want %s)", elem.s, p, target)
+		}
+
+		if v := Sum64([]byte(elem.s)); v != elem.h64_1 {
+			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h64_1)
+		}
+
+		var h128 Hash128 = New128()
+		h128.Write([]byte(elem.s))
+		if v1, v2 := h128.Sum128(); v1 != elem.h64_1 || v2 != elem.h64_2 {
+			t.Errorf("'%s': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, v1, v2, elem.h64_1, elem.h64_2)
+		}
+
+		var h128_byte Hash128 = New128()
+		h128_byte.Write([]byte(elem.s))
+		target = fmt.Sprintf("%016x%016x", elem.h64_1, elem.h64_2)
+		if p := fmt.Sprintf("%x", h128_byte.Sum(nil)); p != target {
+			t.Errorf("'%s': %s (want %s)", elem.s, p, target)
+		}
+
+		if v1, v2 := Sum128([]byte(elem.s)); v1 != elem.h64_1 || v2 != elem.h64_2 {
+			t.Errorf("'%s': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, v1, v2, elem.h64_1, elem.h64_2)
+		}
+	}
+}
+
+func TestIncremental(t *testing.T) {
+	for _, elem := range data {
+		h32 := New32()
+		h128 := New128()
+		for i, j, k := 0, 0, len(elem.s); i < k; i = j {
+			j = 2*i + 3
+			if j > k {
+				j = k
+			}
+			s := elem.s[i:j]
+			print(s + "|")
+			h32.Write([]byte(s))
+			h128.Write([]byte(s))
+		}
+		println()
+		if v := h32.Sum32(); v != elem.h32 {
+			t.Errorf("'%s': 0x%x (want 0x%x)", elem.s, v, elem.h32)
+		}
+		if v1, v2 := h128.Sum128(); v1 != elem.h64_1 || v2 != elem.h64_2 {
+			t.Errorf("'%s': 0x%x-0x%x (want 0x%x-0x%x)", elem.s, v1, v2, elem.h64_1, elem.h64_2)
+		}
+	}
+}
+
+//---
+
+func bench32(b *testing.B, length int) {
+	buf := make([]byte, length)
+	b.SetBytes(int64(length))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Sum32(buf)
+	}
+}
+
+func Benchmark32_1(b *testing.B) {
+	bench32(b, 1)
+}
+func Benchmark32_2(b *testing.B) {
+	bench32(b, 2)
+}
+func Benchmark32_4(b *testing.B) {
+	bench32(b, 4)
+}
+func Benchmark32_8(b *testing.B) {
+	bench32(b, 8)
+}
+func Benchmark32_16(b *testing.B) {
+	bench32(b, 16)
+}
+func Benchmark32_32(b *testing.B) {
+	bench32(b, 32)
+}
+func Benchmark32_64(b *testing.B) {
+	bench32(b, 64)
+}
+func Benchmark32_128(b *testing.B) {
+	bench32(b, 128)
+}
+func Benchmark32_256(b *testing.B) {
+	bench32(b, 256)
+}
+func Benchmark32_512(b *testing.B) {
+	bench32(b, 512)
+}
+func Benchmark32_1024(b *testing.B) {
+	bench32(b, 1024)
+}
+func Benchmark32_2048(b *testing.B) {
+	bench32(b, 2048)
+}
+func Benchmark32_4096(b *testing.B) {
+	bench32(b, 4096)
+}
+func Benchmark32_8192(b *testing.B) {
+	bench32(b, 8192)
+}
+
+//---
+
+func benchPartial32(b *testing.B, length int) {
+	buf := make([]byte, length)
+	b.SetBytes(int64(length))
+
+	start := (32 / 8) / 2
+	chunks := 7
+	k := length / chunks
+	tail := (length - start) % k
+
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		hasher := New32()
+		hasher.Write(buf[0:start])
+
+		for j := start; j+k <= length; j += k {
+			hasher.Write(buf[j : j+k])
+		}
+
+		hasher.Write(buf[length-tail:])
+		hasher.Sum32()
+	}
+}
+
+func BenchmarkPartial32_8(b *testing.B) {
+	benchPartial32(b, 8)
+}
+func BenchmarkPartial32_16(b *testing.B) {
+	benchPartial32(b, 16)
+}
+func BenchmarkPartial32_32(b *testing.B) {
+	benchPartial32(b, 32)
+}
+func BenchmarkPartial32_64(b *testing.B) {
+	benchPartial32(b, 64)
+}
+func BenchmarkPartial32_128(b *testing.B) {
+	benchPartial32(b, 128)
+}
+
+//---
+
+func bench128(b *testing.B, length int) {
+	buf := make([]byte, length)
+	b.SetBytes(int64(length))
+	b.ResetTimer()
+	for i := 0; i < b.N; i++ {
+		Sum128(buf)
+	}
+}
+
+func Benchmark128_1(b *testing.B) {
+	bench128(b, 1)
+}
+func Benchmark128_2(b *testing.B) {
+	bench128(b, 2)
+}
+func Benchmark128_4(b *testing.B) {
+	bench128(b, 4)
+}
+func Benchmark128_8(b *testing.B) {
+	bench128(b, 8)
+}
+func Benchmark128_16(b *testing.B) {
+	bench128(b, 16)
+}
+func Benchmark128_32(b *testing.B) {
+	bench128(b, 32)
+}
+func Benchmark128_64(b *testing.B) {
+	bench128(b, 64)
+}
+func Benchmark128_128(b *testing.B) {
+	bench128(b, 128)
+}
+func Benchmark128_256(b *testing.B) {
+	bench128(b, 256)
+}
+func Benchmark128_512(b *testing.B) {
+	bench128(b, 512)
+}
+func Benchmark128_1024(b *testing.B) {
+	bench128(b, 1024)
+}
+func Benchmark128_2048(b *testing.B) {
+	bench128(b, 2048)
+}
+func Benchmark128_4096(b *testing.B) {
+	bench128(b, 4096)
+}
+func Benchmark128_8192(b *testing.B) {
+	bench128(b, 8192)
+}
+
+//---
diff --git a/vendor/manifest b/vendor/manifest
index 21351d08b8..0f07864761 100644
--- a/vendor/manifest
+++ b/vendor/manifest
@@ -65,6 +65,12 @@
 			"revision": "84c0a38a18fcd2d657f3eabc958433c1f37ecdc0",
 			"branch": "master"
 		},
+		{
+			"importpath": "github.com/coocood/freecache",
+			"repository": "https://github.com/coocood/freecache",
+			"revision": "a27035d5537f1fa5518225e9373c9ec7450f2ea2",
+			"branch": "master"
+		},
 		{
 			"importpath": "github.com/coreos/etcd/Godeps/_workspace/src/bitbucket.org/ww/goautoneg",
 			"repository": "https://github.com/coreos/etcd",
@@ -697,6 +703,12 @@
 			"revision": "244f5ac324cb97e1987ef901a0081a77bfd8e845",
 			"branch": "master"
 		},
+		{
+			"importpath": "github.com/spaolacci/murmur3",
+			"repository": "https://github.com/spaolacci/murmur3",
+			"revision": "0d12bf811670bf6a1a63828dfbd003eded177fce",
+			"branch": "master"
+		},
 		{
 			"importpath": "github.com/spf13/cobra",
 			"repository": "https://github.com/spf13/cobra",
@@ -925,4 +937,4 @@
 			"branch": "master"
 		}
 	]
-}
+}
\ No newline at end of file
diff --git a/xfer/probe_config.go b/xfer/probe_config.go
index 071e832c25..58c1093d4f 100644
--- a/xfer/probe_config.go
+++ b/xfer/probe_config.go
@@ -2,6 +2,7 @@ package xfer
 
 import (
 	"crypto/tls"
+	"crypto/x509"
 	"fmt"
 	"io"
 	"net"
@@ -14,6 +15,16 @@ import (
 // ID is currently set to the a random string on probe startup.
 const ScopeProbeIDHeader = "X-Scope-Probe-ID"
 
+var certPool *x509.CertPool
+
+func init() {
+	var err error
+	certPool, err = gocertifi.CACerts()
+	if err != nil {
+		panic(err)
+	}
+}
+
 // ProbeConfig contains all the info needed for a probe to do HTTP requests
 type ProbeConfig struct {
 	Token    string
@@ -46,10 +57,6 @@ func (pc ProbeConfig) getHTTPTransport(hostname string) (*http.Transport, error)
 		return nil, err
 	}
 
-	certPool, err := gocertifi.CACerts()
-	if err != nil {
-		return nil, err
-	}
 	return &http.Transport{
 		TLSClientConfig: &tls.Config{
 			RootCAs:    certPool,