diff --git a/CHANGELOG.md b/CHANGELOG.md
index afa46baa..9af933de 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,4 +1,5 @@
 # developing
+- Error codes definition of cache module. [4493](https://github.com/beego/beego/pull/4493)
 - Remove generateCommentRoute http hook. Using `bee generate routers` commands instead.[4486](https://github.com/beego/beego/pull/4486) [bee PR 762](https://github.com/beego/bee/pull/762)
 - Fix: /abc.html/aaa match /abc/aaa. [4459](https://github.com/beego/beego/pull/4459)
 - ORM mock. [4407](https://github.com/beego/beego/pull/4407)
diff --git a/ERROR_SPECIFICATION.md b/ERROR_SPECIFICATION.md
index cf2f94b2..68a04bd1 100644
--- a/ERROR_SPECIFICATION.md
+++ b/ERROR_SPECIFICATION.md
@@ -1 +1,5 @@
 # Error Module
+
+## Module code
+- httplib 1
+- cache 2
\ No newline at end of file
diff --git a/client/cache/cache.go b/client/cache/cache.go
index 70c81697..87f7ba62 100644
--- a/client/cache/cache.go
+++ b/client/cache/cache.go
@@ -33,8 +33,9 @@ package cache
 
 import (
 	"context"
-	"fmt"
 	"time"
+
+	"github.com/beego/beego/v2/core/berror"
 )
 
 // Cache interface contains all behaviors for cache adapter.
@@ -55,12 +56,14 @@ type Cache interface {
 	// Set a cached value with key and expire time.
 	Put(ctx context.Context, key string, val interface{}, timeout time.Duration) error
 	// Delete cached value by key.
+	// Should not return error if key not found
 	Delete(ctx context.Context, key string) error
 	// Increment a cached int value by key, as a counter.
 	Incr(ctx context.Context, key string) error
 	// Decrement a cached int value by key, as a counter.
 	Decr(ctx context.Context, key string) error
 	// Check if a cached value exists or not.
+	// if key is expired, return (false, nil)
 	IsExist(ctx context.Context, key string) (bool, error)
 	// Clear all cache.
 	ClearAll(ctx context.Context) error
@@ -78,7 +81,7 @@ var adapters = make(map[string]Instance)
 // it panics.
 func Register(name string, adapter Instance) {
 	if adapter == nil {
-		panic("cache: Register adapter is nil")
+		panic(berror.Error(NilCacheAdapter, "cache: Register adapter is nil").Error())
 	}
 	if _, ok := adapters[name]; ok {
 		panic("cache: Register called twice for adapter " + name)
@@ -92,7 +95,7 @@ func Register(name string, adapter Instance) {
 func NewCache(adapterName, config string) (adapter Cache, err error) {
 	instanceFunc, ok := adapters[adapterName]
 	if !ok {
-		err = fmt.Errorf("cache: unknown adapter name %q (forgot to import?)", adapterName)
+		err = berror.Errorf(UnknownAdapter, "cache: unknown adapter name %s (forgot to import?)", adapterName)
 		return
 	}
 	adapter = instanceFunc()
diff --git a/client/cache/cache_test.go b/client/cache/cache_test.go
index 6cecdc16..db651e94 100644
--- a/client/cache/cache_test.go
+++ b/client/cache/cache_test.go
@@ -18,6 +18,7 @@ import (
 	"context"
 	"math"
 	"os"
+	"strings"
 	"sync"
 	"testing"
 	"time"
@@ -108,7 +109,7 @@ func TestCache(t *testing.T) {
 	assert.Equal(t, "author1", vv[1])
 
 	assert.NotNil(t, err)
-	assert.Equal(t, "key [astaxie0] error: key not exist", err.Error())
+	assert.True(t, strings.Contains(err.Error(), "key isn't exist"))
 }
 
 func TestFileCache(t *testing.T) {
diff --git a/client/cache/calc_utils.go b/client/cache/calc_utils.go
index 733e2fc2..e18946c1 100644
--- a/client/cache/calc_utils.go
+++ b/client/cache/calc_utils.go
@@ -1,46 +1,55 @@
 package cache
 
 import (
-	"fmt"
 	"math"
+
+	"github.com/beego/beego/v2/core/berror"
 )
 
+var (
+	ErrIncrementOverflow = berror.Error(IncrementOverflow, "this incr invocation will overflow.")
+	ErrDecrementOverflow = berror.Error(DecrementOverflow, "this decr invocation will overflow.")
+	ErrNotIntegerType = berror.Error(NotIntegerType, "item val is not (u)int (u)int32 (u)int64")
+)
+
+
+
 func incr(originVal interface{}) (interface{}, error) {
 	switch val := originVal.(type) {
 	case int:
 		tmp := val + 1
 		if val > 0 && tmp < 0 {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrIncrementOverflow
 		}
 		return tmp, nil
 	case int32:
 		if val == math.MaxInt32 {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrIncrementOverflow
 		}
 		return val + 1, nil
 	case int64:
 		if val == math.MaxInt64 {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrIncrementOverflow
 		}
 		return val + 1, nil
 	case uint:
 		tmp := val + 1
 		if tmp < val {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrIncrementOverflow
 		}
 		return tmp, nil
 	case uint32:
 		if val == math.MaxUint32 {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrIncrementOverflow
 		}
 		return val + 1, nil
 	case uint64:
 		if val == math.MaxUint64 {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrIncrementOverflow
 		}
 		return val + 1, nil
 	default:
-		return nil, fmt.Errorf("item val is not (u)int (u)int32 (u)int64")
+		return nil, ErrNotIntegerType
 	}
 }
 
@@ -49,35 +58,35 @@ func decr(originVal interface{}) (interface{}, error) {
 	case int:
 		tmp := val - 1
 		if val < 0 && tmp > 0 {
-			return nil, fmt.Errorf("decrement would overflow")
+			return nil, ErrDecrementOverflow
 		}
 		return tmp, nil
 	case int32:
 		if val == math.MinInt32 {
-			return nil, fmt.Errorf("decrement would overflow")
+			return nil, ErrDecrementOverflow
 		}
 		return val - 1, nil
 	case int64:
 		if val == math.MinInt64 {
-			return nil, fmt.Errorf("decrement would overflow")
+			return nil, ErrDecrementOverflow
 		}
 		return val - 1, nil
 	case uint:
 		if val == 0 {
-			return nil, fmt.Errorf("decrement would overflow")
+			return nil, ErrDecrementOverflow
 		}
 		return val - 1, nil
 	case uint32:
 		if val == 0 {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrDecrementOverflow
 		}
 		return val - 1, nil
 	case uint64:
 		if val == 0 {
-			return nil, fmt.Errorf("increment would overflow")
+			return nil, ErrDecrementOverflow
 		}
 		return val - 1, nil
 	default:
-		return nil, fmt.Errorf("item val is not (u)int (u)int32 (u)int64")
+		return nil, ErrNotIntegerType
 	}
 }
diff --git a/client/cache/calc_utils_test.go b/client/cache/calc_utils_test.go
index 2a08dfc3..1f8d3377 100644
--- a/client/cache/calc_utils_test.go
+++ b/client/cache/calc_utils_test.go
@@ -14,61 +14,64 @@ func TestIncr(t *testing.T) {
 	var updateVal interface{} = int(2)
 	val, err := incr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = incr(int(1<<(strconv.IntSize-1) - 1))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrIncrementOverflow, err)
 
 	// int32
 	originVal = int32(1)
 	updateVal = int32(2)
 	val, err = incr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = incr(int32(math.MaxInt32))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrIncrementOverflow, err)
+
 	// int64
 	originVal = int64(1)
 	updateVal = int64(2)
 	val, err = incr(originVal)
 	assert.Nil(t, err)
-
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
 
 	_, err = incr(int64(math.MaxInt64))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrIncrementOverflow, err)
 
 	// uint
 	originVal = uint(1)
 	updateVal = uint(2)
 	val, err = incr(originVal)
-	assert.Nil(t, err)
 
-	assert.Equal(t, updateVal, val)
+	assert.Nil(t, err)
+	assert.Equal(t, val, updateVal)
 
 	_, err = incr(uint(1<<(strconv.IntSize) - 1))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrIncrementOverflow, err)
+
 	// uint32
 	originVal = uint32(1)
 	updateVal = uint32(2)
 	val, err = incr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
 
 	_, err = incr(uint32(math.MaxUint32))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrIncrementOverflow, err)
 
 	// uint64
 	originVal = uint64(1)
 	updateVal = uint64(2)
 	val, err = incr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
-	_, err = incr(uint64(math.MaxUint64))
-	assert.NotNil(t, err)
+	assert.Equal(t, val, updateVal)
 
+	_, err = incr(uint64(math.MaxUint64))
+	assert.Equal(t, ErrIncrementOverflow, err)
 	// other type
 	_, err = incr("string")
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrNotIntegerType, err)
 }
 
 func TestDecr(t *testing.T) {
@@ -77,57 +80,61 @@ func TestDecr(t *testing.T) {
 	var updateVal interface{} = int(1)
 	val, err := decr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = decr(int(-1 << (strconv.IntSize - 1)))
-
-	assert.NotNil(t, err)
-
+	assert.Equal(t, ErrDecrementOverflow, err)
 	// int32
 	originVal = int32(2)
 	updateVal = int32(1)
 	val, err = decr(originVal)
-
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = decr(int32(math.MinInt32))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrDecrementOverflow, err)
 
 	// int64
 	originVal = int64(2)
 	updateVal = int64(1)
 	val, err = decr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = decr(int64(math.MinInt64))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrDecrementOverflow, err)
+
 	// uint
 	originVal = uint(2)
 	updateVal = uint(1)
 	val, err = decr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = decr(uint(0))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrDecrementOverflow, err)
 
 	// uint32
 	originVal = uint32(2)
 	updateVal = uint32(1)
 	val, err = decr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = decr(uint32(0))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrDecrementOverflow, err)
 
 	// uint64
 	originVal = uint64(2)
 	updateVal = uint64(1)
 	val, err = decr(originVal)
 	assert.Nil(t, err)
-	assert.Equal(t, updateVal, val)
+	assert.Equal(t, val, updateVal)
+
 	_, err = decr(uint64(0))
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrDecrementOverflow, err)
 
 	// other type
 	_, err = decr("string")
-	assert.NotNil(t, err)
+	assert.Equal(t, ErrNotIntegerType, err)
 }
diff --git a/client/cache/error_code.go b/client/cache/error_code.go
new file mode 100644
index 00000000..4305d7e4
--- /dev/null
+++ b/client/cache/error_code.go
@@ -0,0 +1,182 @@
+// Copyright 2021 beego
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cache
+
+import (
+	"github.com/beego/beego/v2/core/berror"
+)
+
+var NilCacheAdapter = berror.DefineCode(4002001, moduleName, "NilCacheAdapter", `
+It means that you register cache adapter by pass nil.
+A cache adapter is an instance of Cache interface. 
+`)
+
+var DuplicateAdapter = berror.DefineCode(4002002, moduleName, "DuplicateAdapter", `
+You register two adapter with same name. In beego cache module, one name one adapter.
+Once you got this error, please check the error stack, search adapter 
+`)
+
+var UnknownAdapter = berror.DefineCode(4002003, moduleName, "UnknownAdapter", `
+Unknown adapter, do you forget to register the adapter?
+You must register adapter before use it. For example, if you want to use redis implementation, 
+you must import the cache/redis package.
+`)
+
+var IncrementOverflow = berror.DefineCode(4002004, moduleName, "IncrementOverflow", `
+The increment operation will overflow.
+`)
+
+var DecrementOverflow = berror.DefineCode(4002005, moduleName, "DecrementOverflow", `
+The decrement operation will overflow.
+`)
+
+var NotIntegerType = berror.DefineCode(4002006, moduleName, "NotIntegerType", `
+The type of value is not (u)int (u)int32 (u)int64. 
+When you want to call Incr or Decr function of Cache API, you must confirm that the value's type is one of (u)int (u)int32 (u)int64.
+`)
+
+var InvalidFileCacheDirectoryLevelCfg = berror.DefineCode(4002007, moduleName, "InvalidFileCacheDirectoryLevelCfg", `
+You pass invalid DirectoryLevel parameter when you try to StartAndGC file cache instance.
+This parameter must be a integer, and please check your input.
+`)
+
+var InvalidFileCacheEmbedExpiryCfg = berror.DefineCode(4002008, moduleName, "InvalidFileCacheEmbedExpiryCfg", `
+You pass invalid EmbedExpiry parameter when you try to StartAndGC file cache instance.
+This parameter must be a integer, and please check your input.
+`)
+
+var CreateFileCacheDirFailed = berror.DefineCode(4002009, moduleName, "CreateFileCacheDirFailed", `
+Beego failed to create file cache directory. There are two cases:
+1. You pass invalid CachePath parameter. Please check your input.
+2. Beego doesn't have the permission to create this directory. Please check your file mode.
+`)
+
+var InvalidFileCachePath = berror.DefineCode(4002010, moduleName, "InvalidFilePath", `
+The file path of FileCache is invalid. Please correct the config.
+`)
+
+var ReadFileCacheContentFailed = berror.DefineCode(4002011, moduleName, "ReadFileCacheContentFailed", `
+Usually you won't got this error. It means that Beego cannot read the data from the file.
+You need to check whether the file exist. Sometimes it may be deleted by other processes.
+If the file exists, please check the permission that Beego is able to read data from the file.
+`)
+
+var InvalidGobEncodedData = berror.DefineCode(4002012, moduleName, "InvalidEncodedData", `
+The data is invalid. When you try to decode the invalid data, you got this error.
+Please confirm that the data is encoded by GOB correctly.
+`)
+
+var GobEncodeDataFailed = berror.DefineCode(4002013, moduleName, "GobEncodeDataFailed", `
+Beego could not encode the data to GOB byte array. In general, the data type is invalid. 
+For example, GOB doesn't support function type.
+Basic types, string, structure, structure pointer are supported. 
+`)
+
+var KeyExpired = berror.DefineCode(4002014, moduleName, "KeyExpired", `
+Cache key is expired.
+You should notice that, a key is expired and then it may be deleted by GC goroutine. 
+So when you query a key which may be expired, you may got this code, or KeyNotExist.
+`)
+
+var KeyNotExist = berror.DefineCode(4002015, moduleName, "KeyNotExist", `
+Key not found.
+`)
+
+var MultiGetFailed = berror.DefineCode(4002016, moduleName, "MultiGetFailed", `
+Get multiple keys failed. Please check the detail msg to find out the root cause.
+`)
+
+var InvalidMemoryCacheCfg = berror.DefineCode(4002017, moduleName, "InvalidMemoryCacheCfg", `
+The config is invalid. Please check your input. It must be a json string.
+`)
+
+var InvalidMemCacheCfg = berror.DefineCode(4002018, moduleName, "InvalidMemCacheCfg", `
+The config is invalid. Please check your input, it must be json string and contains "conn" field.
+`)
+
+var InvalidMemCacheValue = berror.DefineCode(4002019, moduleName, "InvalidMemCacheValue", `
+The value must be string or byte[], please check your input.
+`)
+
+var InvalidRedisCacheCfg = berror.DefineCode(4002020, moduleName, "InvalidRedisCacheCfg", `
+The config must be json string, and has "conn" field.
+`)
+
+var InvalidSsdbCacheCfg = berror.DefineCode(4002021, moduleName, "InvalidSsdbCacheCfg", `
+The config must be json string, and has "conn" field. The value of "conn" field should be "host:port".
+"port" must be a valid integer.
+`)
+
+var InvalidSsdbCacheValue = berror.DefineCode(4002022, moduleName, "InvalidSsdbCacheValue", `
+SSDB cache only accept string value. Please check your input.
+`)
+
+
+
+
+
+
+
+
+
+var DeleteFileCacheItemFailed = berror.DefineCode(5002001, moduleName, "DeleteFileCacheItemFailed", `
+Beego try to delete file cache item failed. 
+Please check whether Beego generated file correctly. 
+And then confirm whether this file is already deleted by other processes or other people.
+`)
+
+var MemCacheCurdFailed = berror.DefineCode(5002002, moduleName, "MemCacheError", `
+When you want to get, put, delete key-value from remote memcache servers, you may get error:
+1. You pass invalid servers address, so Beego could not connect to remote server;
+2. The servers address is correct, but there is some net issue. Typically there is some firewalls between application and memcache server;
+3. Key is invalid. The key's length should be less than 250 and must not contains special characters;
+4. The response from memcache server is invalid;
+`)
+
+var RedisCacheCurdFailed = berror.DefineCode(5002003, moduleName, "RedisCacheCurdFailed", `
+When Beego uses client to send request to redis server, it failed.
+1. The server addresses is invalid;
+2. Network issue, firewall issue or network is unstable;
+3. Client failed to manage connection. In extreme cases, Beego's redis client didn't maintain connections correctly, for example, Beego try to send request via closed connection;
+4. The request are huge and redis server spent too much time to process it, and client is timeout;
+
+In general, if you always got this error whatever you do, in most cases, it was caused by network issue. 
+You could check your network state, and confirm that firewall rules are correct.
+`)
+
+var InvalidConnection = berror.DefineCode(5002004, moduleName, "InvalidConnection", `
+The connection is invalid. Please check your connection info, network, firewall.
+You could simply uses ping, telnet or write some simple tests to test network.
+`)
+
+var DialFailed = berror.DefineCode(5002005, moduleName, "DialFailed", `
+When Beego try to dial to remote servers, it failed. Please check your connection info and network state, server state.
+`)
+
+var SsdbCacheCurdFailed = berror.DefineCode(5002006, moduleName, "SsdbCacheCurdFailed", `
+When you try to use SSDB cache, it failed. There are many cases:
+1. servers unavailable;
+2. network issue, including network unstable, firewall;
+3. connection issue;
+4. request are huge and servers spent too much time to process it, got timeout;
+`)
+
+var SsdbBadResponse = berror.DefineCode(5002007, moduleName, "SsdbBadResponse", `
+The reponse from SSDB server is invalid. 
+Usually it indicates something wrong on server side.
+`)
+
+var ErrKeyExpired = berror.Error(KeyExpired, "the key is expired")
+var ErrKeyNotExist = berror.Error(KeyNotExist, "the key isn't exist")
\ No newline at end of file
diff --git a/client/cache/file.go b/client/cache/file.go
index 87e14b6c..ea00c72e 100644
--- a/client/cache/file.go
+++ b/client/cache/file.go
@@ -30,7 +30,7 @@ import (
 	"strings"
 	"time"
 
-	"github.com/pkg/errors"
+	"github.com/beego/beego/v2/core/berror"
 )
 
 // FileCacheItem is basic unit of file cache adapter which
@@ -73,38 +73,60 @@ func (fc *FileCache) StartAndGC(config string) error {
 	if err != nil {
 		return err
 	}
-	if _, ok := cfg["CachePath"]; !ok {
-		cfg["CachePath"] = FileCachePath
-	}
-	if _, ok := cfg["FileSuffix"]; !ok {
-		cfg["FileSuffix"] = FileCacheFileSuffix
-	}
-	if _, ok := cfg["DirectoryLevel"]; !ok {
-		cfg["DirectoryLevel"] = strconv.Itoa(FileCacheDirectoryLevel)
-	}
-	if _, ok := cfg["EmbedExpiry"]; !ok {
-		cfg["EmbedExpiry"] = strconv.FormatInt(int64(FileCacheEmbedExpiry.Seconds()), 10)
-	}
-	fc.CachePath = cfg["CachePath"]
-	fc.FileSuffix = cfg["FileSuffix"]
-	fc.DirectoryLevel, _ = strconv.Atoi(cfg["DirectoryLevel"])
-	fc.EmbedExpiry, _ = strconv.Atoi(cfg["EmbedExpiry"])
 
-	fc.Init()
-	return nil
+	const cpKey = "CachePath"
+	const fsKey = "FileSuffix"
+	const dlKey = "DirectoryLevel"
+	const eeKey = "EmbedExpiry"
+
+	if _, ok := cfg[cpKey]; !ok {
+		cfg[cpKey] = FileCachePath
+	}
+
+	if _, ok := cfg[fsKey]; !ok {
+		cfg[fsKey] = FileCacheFileSuffix
+	}
+
+	if _, ok := cfg[dlKey]; !ok {
+		cfg[dlKey] = strconv.Itoa(FileCacheDirectoryLevel)
+	}
+
+	if _, ok := cfg[eeKey]; !ok {
+		cfg[eeKey] = strconv.FormatInt(int64(FileCacheEmbedExpiry.Seconds()), 10)
+	}
+	fc.CachePath = cfg[cpKey]
+	fc.FileSuffix = cfg[fsKey]
+	fc.DirectoryLevel, err = strconv.Atoi(cfg[dlKey])
+	if err != nil {
+		return berror.Wrapf(err, InvalidFileCacheDirectoryLevelCfg,
+			"invalid directory level config, please check your input, it must be integer: %s", cfg[dlKey])
+	}
+	fc.EmbedExpiry, err = strconv.Atoi(cfg[eeKey])
+	if err != nil {
+		return berror.Wrapf(err, InvalidFileCacheEmbedExpiryCfg,
+			"invalid embed expiry config, please check your input, it must be integer: %s", cfg[eeKey])
+	}
+	return fc.Init()
 }
 
 // Init makes new a dir for file cache if it does not already exist
-func (fc *FileCache) Init() {
-	if ok, _ := exists(fc.CachePath); !ok { // todo : error handle
-		_ = os.MkdirAll(fc.CachePath, os.ModePerm) // todo : error handle
+func (fc *FileCache) Init() error {
+	ok, err := exists(fc.CachePath)
+	if err != nil || ok {
+		return err
 	}
+	err = os.MkdirAll(fc.CachePath, os.ModePerm)
+	if err != nil {
+		return berror.Wrapf(err, CreateFileCacheDirFailed,
+			"could not create directory, please check the config [%s] and file mode.", fc.CachePath)
+	}
+	return nil
 }
 
 // getCachedFilename returns an md5 encoded file name.
-func (fc *FileCache) getCacheFileName(key string) string {
+func (fc *FileCache) getCacheFileName(key string) (string, error) {
 	m := md5.New()
-	io.WriteString(m, key)
+	_, _ = io.WriteString(m, key)
 	keyMd5 := hex.EncodeToString(m.Sum(nil))
 	cachePath := fc.CachePath
 	switch fc.DirectoryLevel {
@@ -113,18 +135,29 @@ func (fc *FileCache) getCacheFileName(key string) string {
 	case 1:
 		cachePath = filepath.Join(cachePath, keyMd5[0:2])
 	}
-
-	if ok, _ := exists(cachePath); !ok { // todo : error handle
-		_ = os.MkdirAll(cachePath, os.ModePerm) // todo : error handle
+	ok, err := exists(cachePath)
+	if err != nil {
+		return "", err
+	}
+	if !ok {
+		err  = os.MkdirAll(cachePath, os.ModePerm)
+		if err != nil {
+			return "", berror.Wrapf(err, CreateFileCacheDirFailed,
+				"could not create the directory: %s", cachePath)
+		}
 	}
 
-	return filepath.Join(cachePath, fmt.Sprintf("%s%s", keyMd5, fc.FileSuffix))
+	return filepath.Join(cachePath, fmt.Sprintf("%s%s", keyMd5, fc.FileSuffix)), nil
 }
 
 // Get value from file cache.
 // if nonexistent or expired return an empty string.
 func (fc *FileCache) Get(ctx context.Context, key string) (interface{}, error) {
-	fileData, err := FileGetContents(fc.getCacheFileName(key))
+	fn, err := fc.getCacheFileName(key)
+	if err != nil {
+		return nil, err
+	}
+	fileData, err := FileGetContents(fn)
 	if err != nil {
 		return nil, err
 	}
@@ -136,7 +169,7 @@ func (fc *FileCache) Get(ctx context.Context, key string) (interface{}, error) {
 	}
 
 	if to.Expired.Before(time.Now()) {
-		return nil, errors.New("The key is expired")
+		return nil, ErrKeyExpired
 	}
 	return to.Data, nil
 }
@@ -159,7 +192,7 @@ func (fc *FileCache) GetMulti(ctx context.Context, keys []string) ([]interface{}
 	if len(keysErr) == 0 {
 		return rc, nil
 	}
-	return rc, errors.New(strings.Join(keysErr, "; "))
+	return rc, berror.Error(MultiGetFailed, strings.Join(keysErr, "; "))
 }
 
 // Put value into file cache.
@@ -179,14 +212,26 @@ func (fc *FileCache) Put(ctx context.Context, key string, val interface{}, timeo
 	if err != nil {
 		return err
 	}
-	return FilePutContents(fc.getCacheFileName(key), data)
+
+	fn, err := fc.getCacheFileName(key)
+	if err != nil {
+		return err
+	}
+	return FilePutContents(fn, data)
 }
 
 // Delete file cache value.
 func (fc *FileCache) Delete(ctx context.Context, key string) error {
-	filename := fc.getCacheFileName(key)
+	filename, err := fc.getCacheFileName(key)
+	if err != nil {
+		return err
+	}
 	if ok, _ := exists(filename); ok {
-		return os.Remove(filename)
+		err = os.Remove(filename)
+		if err != nil {
+			return berror.Wrapf(err, DeleteFileCacheItemFailed,
+				"can not delete this file cache key-value, key is %s and file name is %s", key, filename)
+		}
 	}
 	return nil
 }
@@ -224,8 +269,11 @@ func (fc *FileCache) Decr(ctx context.Context, key string) error {
 
 // IsExist checks if value exists.
 func (fc *FileCache) IsExist(ctx context.Context, key string) (bool, error) {
-	ret, _ := exists(fc.getCacheFileName(key))
-	return ret, nil
+	fn, err := fc.getCacheFileName(key)
+	if err != nil {
+		return false, err
+	}
+	return exists(fn)
 }
 
 // ClearAll cleans cached files (not implemented)
@@ -242,13 +290,19 @@ func exists(path string) (bool, error) {
 	if os.IsNotExist(err) {
 		return false, nil
 	}
-	return false, err
+	return false, berror.Wrapf(err, InvalidFileCachePath, "file cache path is invalid: %s", path)
 }
 
 // FileGetContents Reads bytes from a file.
 // if non-existent, create this file.
-func FileGetContents(filename string) (data []byte, e error) {
-	return ioutil.ReadFile(filename)
+func FileGetContents(filename string) ([]byte, error) {
+	data, err := ioutil.ReadFile(filename)
+	if err != nil {
+		return nil, berror.Wrapf(err, ReadFileCacheContentFailed,
+			"could not read the data from the file: %s, " +
+			"please confirm that file exist and Beego has the permission to read the content.", filename)
+	}
+	return data, nil
 }
 
 // FilePutContents puts bytes into a file.
@@ -263,16 +317,21 @@ func GobEncode(data interface{}) ([]byte, error) {
 	enc := gob.NewEncoder(buf)
 	err := enc.Encode(data)
 	if err != nil {
-		return nil, err
+		return nil, berror.Wrap(err, GobEncodeDataFailed, "could not encode this data")
 	}
-	return buf.Bytes(), err
+	return buf.Bytes(), nil
 }
 
 // GobDecode Gob decodes a file cache item.
 func GobDecode(data []byte, to *FileCacheItem) error {
 	buf := bytes.NewBuffer(data)
 	dec := gob.NewDecoder(buf)
-	return dec.Decode(&to)
+	err := dec.Decode(&to)
+	if err != nil {
+		return berror.Wrap(err, InvalidGobEncodedData,
+			"could not decode this data to FileCacheItem. Make sure that the data is encoded by GOB.")
+	}
+	return nil
 }
 
 func init() {
diff --git a/client/cache/file_test.go b/client/cache/file_test.go
new file mode 100644
index 00000000..3ffc27f3
--- /dev/null
+++ b/client/cache/file_test.go
@@ -0,0 +1,108 @@
+// Copyright 2021 beego
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cache
+
+import (
+	"context"
+	"fmt"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestFileCacheStartAndGC(t *testing.T) {
+	fc := NewFileCache().(*FileCache)
+	err := fc.StartAndGC(`{`)
+	assert.NotNil(t, err)
+	err = fc.StartAndGC(`{}`)
+	assert.Nil(t, err)
+
+	assert.Equal(t, fc.CachePath, FileCachePath)
+	assert.Equal(t, fc.DirectoryLevel, FileCacheDirectoryLevel)
+	assert.Equal(t, fc.EmbedExpiry, int(FileCacheEmbedExpiry))
+	assert.Equal(t, fc.FileSuffix, FileCacheFileSuffix)
+
+	err = fc.StartAndGC(`{"CachePath":"/cache","FileSuffix":".bin","DirectoryLevel":"2","EmbedExpiry":"0"}`)
+	// could not create dir
+	assert.NotNil(t, err)
+
+	str := getTestCacheFilePath()
+	err = fc.StartAndGC(fmt.Sprintf(`{"CachePath":"%s","FileSuffix":".bin","DirectoryLevel":"2","EmbedExpiry":"0"}`, str))
+	assert.Nil(t, err)
+	assert.Equal(t, fc.CachePath, str)
+	assert.Equal(t, fc.DirectoryLevel, 2)
+	assert.Equal(t, fc.EmbedExpiry, 0)
+	assert.Equal(t, fc.FileSuffix, ".bin")
+
+	err = fc.StartAndGC(fmt.Sprintf(`{"CachePath":"%s","FileSuffix":".bin","DirectoryLevel":"aaa","EmbedExpiry":"0"}`, str))
+	assert.NotNil(t, err)
+
+	err = fc.StartAndGC(fmt.Sprintf(`{"CachePath":"%s","FileSuffix":".bin","DirectoryLevel":"2","EmbedExpiry":"aaa"}`, str))
+	assert.NotNil(t, err)
+}
+
+func TestFileCacheInit(t *testing.T) {
+	fc := NewFileCache().(*FileCache)
+	fc.CachePath = "////aaa"
+	err := fc.Init()
+	assert.NotNil(t, err)
+	fc.CachePath = getTestCacheFilePath()
+	err = fc.Init()
+	assert.Nil(t, err)
+}
+
+func TestFileGetContents(t *testing.T) {
+	_, err := FileGetContents("/bin/aaa")
+	assert.NotNil(t, err)
+	fn := filepath.Join(os.TempDir(), "fileCache.txt")
+	f, err := os.Create(fn)
+	assert.Nil(t, err)
+	_, err = f.WriteString("text")
+	assert.Nil(t, err)
+	data, err := FileGetContents(fn)
+	assert.Nil(t, err)
+	assert.Equal(t, "text", string(data))
+}
+
+func TestGobEncodeDecode(t *testing.T) {
+	_, err := GobEncode(func() {
+		fmt.Print("test func")
+	})
+	assert.NotNil(t, err)
+	data, err := GobEncode(&FileCacheItem{
+		Data: "hello",
+	})
+	assert.Nil(t, err)
+	err = GobDecode([]byte("wrong data"), &FileCacheItem{})
+	assert.NotNil(t, err)
+	dci := &FileCacheItem{}
+	err = GobDecode(data, dci)
+	assert.Nil(t, err)
+	assert.Equal(t, "hello", dci.Data)
+}
+
+func TestFileCacheDelete(t *testing.T) {
+	fc := NewFileCache()
+	err := fc.StartAndGC(`{}`)
+	assert.Nil(t, err)
+	err = fc.Delete(context.Background(), "my-key")
+	assert.Nil(t, err)
+}
+
+func getTestCacheFilePath() string {
+	return filepath.Join(os.TempDir(), "test", "file.txt")
+}
\ No newline at end of file
diff --git a/client/cache/memcache/memcache.go b/client/cache/memcache/memcache.go
index bbafbd94..3816444f 100644
--- a/client/cache/memcache/memcache.go
+++ b/client/cache/memcache/memcache.go
@@ -32,7 +32,6 @@ package memcache
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"strings"
 	"time"
@@ -40,6 +39,7 @@ import (
 	"github.com/bradfitz/gomemcache/memcache"
 
 	"github.com/beego/beego/v2/client/cache"
+	"github.com/beego/beego/v2/core/berror"
 )
 
 // Cache Memcache adapter.
@@ -55,30 +55,25 @@ func NewMemCache() cache.Cache {
 
 // Get get value from memcache.
 func (rc *Cache) Get(ctx context.Context, key string) (interface{}, error) {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return nil, err
-		}
-	}
 	if item, err := rc.conn.Get(key); err == nil {
 		return item.Value, nil
 	} else {
-		return nil, err
+		return nil, berror.Wrapf(err, cache.MemCacheCurdFailed,
+			"could not read data from memcache, please check your key, network and connection. Root cause: %s",
+			err.Error())
 	}
 }
 
 // GetMulti gets a value from a key in memcache.
 func (rc *Cache) GetMulti(ctx context.Context, keys []string) ([]interface{}, error) {
 	rv := make([]interface{}, len(keys))
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return rv, err
-		}
-	}
 
 	mv, err := rc.conn.GetMulti(keys)
 	if err != nil {
-		return rv, err
+		return rv, berror.Wrapf(err, cache.MemCacheCurdFailed,
+			"could not read multiple key-values from memcache, " +
+			"please check your keys, network and connection. Root cause: %s",
+			err.Error())
 	}
 
 	keysErr := make([]string, 0)
@@ -93,78 +88,54 @@ func (rc *Cache) GetMulti(ctx context.Context, keys []string) ([]interface{}, er
 	if len(keysErr) == 0 {
 		return rv, nil
 	}
-	return rv, fmt.Errorf(strings.Join(keysErr, "; "))
+	return rv, berror.Error(cache.MultiGetFailed, strings.Join(keysErr, "; "))
 }
 
 // Put puts a value into memcache.
 func (rc *Cache) Put(ctx context.Context, key string, val interface{}, timeout time.Duration) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	item := memcache.Item{Key: key, Expiration: int32(timeout / time.Second)}
 	if v, ok := val.([]byte); ok {
 		item.Value = v
 	} else if str, ok := val.(string); ok {
 		item.Value = []byte(str)
 	} else {
-		return errors.New("val only support string and []byte")
+		return berror.Errorf(cache.InvalidMemCacheValue,
+			"the value must be string or byte[]. key: %s, value:%v", key, val)
 	}
-	return rc.conn.Set(&item)
+	return berror.Wrapf(rc.conn.Set(&item), cache.MemCacheCurdFailed,
+		"could not put key-value to memcache, key: %s", key)
 }
 
 // Delete deletes a value in memcache.
 func (rc *Cache) Delete(ctx context.Context, key string) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
-	return rc.conn.Delete(key)
+	return berror.Wrapf(rc.conn.Delete(key), cache.MemCacheCurdFailed,
+		"could not delete key-value from memcache, key: %s", key)
 }
 
 // Incr increases counter.
 func (rc *Cache) Incr(ctx context.Context, key string) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	_, err := rc.conn.Increment(key, 1)
-	return err
+	return berror.Wrapf(err, cache.MemCacheCurdFailed,
+		"could not increase value for key: %s", key)
 }
 
 // Decr decreases counter.
 func (rc *Cache) Decr(ctx context.Context, key string) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	_, err := rc.conn.Decrement(key, 1)
-	return err
+	return berror.Wrapf(err, cache.MemCacheCurdFailed,
+		"could not decrease value for key: %s", key)
 }
 
 // IsExist checks if a value exists in memcache.
 func (rc *Cache) IsExist(ctx context.Context, key string) (bool, error) {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return false, err
-		}
-	}
-	_, err := rc.conn.Get(key)
+	_, err := rc.Get(ctx, key)
 	return err == nil, err
 }
 
 // ClearAll clears all cache in memcache.
 func (rc *Cache) ClearAll(context.Context) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
-	return rc.conn.FlushAll()
+	return berror.Wrap(rc.conn.FlushAll(), cache.MemCacheCurdFailed,
+		"try to clear all key-value pairs failed")
 }
 
 // StartAndGC starts the memcache adapter.
@@ -172,21 +143,15 @@ func (rc *Cache) ClearAll(context.Context) error {
 // If an error occurs during connecting, an error is returned
 func (rc *Cache) StartAndGC(config string) error {
 	var cf map[string]string
-	json.Unmarshal([]byte(config), &cf)
+	if err := json.Unmarshal([]byte(config), &cf); err != nil {
+		return berror.Wrapf(err, cache.InvalidMemCacheCfg,
+			"could not unmarshal this config, it must be valid json stringP: %s", config)
+	}
+
 	if _, ok := cf["conn"]; !ok {
-		return errors.New("config has no conn key")
+		return berror.Errorf(cache.InvalidMemCacheCfg, `config must contains "conn" field: %s`, config)
 	}
 	rc.conninfo = strings.Split(cf["conn"], ";")
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-// connect to memcache and keep the connection.
-func (rc *Cache) connectInit() error {
 	rc.conn = memcache.New(rc.conninfo...)
 	return nil
 }
diff --git a/client/cache/memcache/memcache_test.go b/client/cache/memcache/memcache_test.go
index ea528d63..a6c1f19c 100644
--- a/client/cache/memcache/memcache_test.go
+++ b/client/cache/memcache/memcache_test.go
@@ -19,6 +19,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -106,7 +107,7 @@ func TestMemcacheCache(t *testing.T) {
 	assert.Equal(t, "author1", string(vv[1].([]byte)))
 
 	assert.NotNil(t, err)
-	assert.Equal(t, "key [astaxie0] error: key not exist", err.Error())
+	assert.True(t, strings.Contains(err.Error(), "key not exist"))
 
 	assert.Nil(t, bm.ClearAll(context.Background()))
 	// test clear all
diff --git a/client/cache/memory.go b/client/cache/memory.go
index 8dab5f2d..e4b704c9 100644
--- a/client/cache/memory.go
+++ b/client/cache/memory.go
@@ -17,11 +17,12 @@ package cache
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"strings"
 	"sync"
 	"time"
+
+	"github.com/beego/beego/v2/core/berror"
 )
 
 var (
@@ -29,8 +30,6 @@ var (
 	DefaultEvery = 60 // 1 minute
 )
 
-const keyNotExistMsg = "key not exist"
-
 // MemoryItem stores memory cache item.
 type MemoryItem struct {
 	val         interface{}
@@ -66,13 +65,14 @@ func NewMemoryCache() Cache {
 func (bc *MemoryCache) Get(ctx context.Context, key string) (interface{}, error) {
 	bc.RLock()
 	defer bc.RUnlock()
-	if itm, ok := bc.items[key]; ok {
+	if itm, ok :=
+	 	bc.items[key]; ok {
 		if itm.isExpire() {
-			return nil, errors.New("the key is expired")
+			return nil, ErrKeyExpired
 		}
 		return itm.val, nil
 	}
-	return nil, errors.New(keyNotExistMsg)
+	return nil, ErrKeyNotExist
 }
 
 // GetMulti gets caches from memory.
@@ -93,7 +93,7 @@ func (bc *MemoryCache) GetMulti(ctx context.Context, keys []string) ([]interface
 	if len(keysErr) == 0 {
 		return rc, nil
 	}
-	return rc, errors.New(strings.Join(keysErr, "; "))
+	return rc, berror.Error(MultiGetFailed, strings.Join(keysErr, "; "))
 }
 
 // Put puts cache into memory.
@@ -110,17 +110,11 @@ func (bc *MemoryCache) Put(ctx context.Context, key string, val interface{}, tim
 }
 
 // Delete cache in memory.
+// If the key is not found, it will not return error
 func (bc *MemoryCache) Delete(ctx context.Context, key string) error {
 	bc.Lock()
 	defer bc.Unlock()
-	if _, ok := bc.items[key]; !ok {
-		
-		return errors.New(keyNotExistMsg)
-	}
 	delete(bc.items, key)
-	if _, ok := bc.items[key]; ok {
-		return errors.New("delete key error")
-	}
 	return nil
 }
 
@@ -131,7 +125,7 @@ func (bc *MemoryCache) Incr(ctx context.Context, key string) error {
 	defer bc.Unlock()
 	itm, ok := bc.items[key]
 	if !ok {
-		return errors.New(keyNotExistMsg)
+		return ErrKeyNotExist
 	}
 
 	val, err := incr(itm.val)
@@ -148,7 +142,7 @@ func (bc *MemoryCache) Decr(ctx context.Context, key string) error {
 	defer bc.Unlock()
 	itm, ok := bc.items[key]
 	if !ok {
-		return errors.New(keyNotExistMsg)
+		return ErrKeyNotExist
 	}
 
 	val, err := decr(itm.val)
@@ -180,7 +174,9 @@ func (bc *MemoryCache) ClearAll(context.Context) error {
 // StartAndGC starts memory cache. Checks expiration in every clock time.
 func (bc *MemoryCache) StartAndGC(config string) error {
 	var cf map[string]int
-	json.Unmarshal([]byte(config), &cf)
+	if err := json.Unmarshal([]byte(config), &cf); err != nil {
+		return berror.Wrapf(err, InvalidMemoryCacheCfg, "invalid config, please check your input: %s", config)
+	}
 	if _, ok := cf["interval"]; !ok {
 		cf = make(map[string]int)
 		cf["interval"] = DefaultEvery
diff --git a/client/cache/module.go b/client/cache/module.go
new file mode 100644
index 00000000..5a4e499e
--- /dev/null
+++ b/client/cache/module.go
@@ -0,0 +1,17 @@
+// Copyright 2021 beego
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package cache
+
+const moduleName = "cache"
diff --git a/client/cache/redis/redis.go b/client/cache/redis/redis.go
index 180222ae..7e70af2e 100644
--- a/client/cache/redis/redis.go
+++ b/client/cache/redis/redis.go
@@ -32,7 +32,6 @@ package redis
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -41,6 +40,7 @@ import (
 	"github.com/gomodule/redigo/redis"
 
 	"github.com/beego/beego/v2/client/cache"
+	"github.com/beego/beego/v2/core/berror"
 )
 
 var (
@@ -67,15 +67,20 @@ func NewRedisCache() cache.Cache {
 }
 
 // Execute the redis commands. args[0] must be the key name
-func (rc *Cache) do(commandName string, args ...interface{}) (reply interface{}, err error) {
-	if len(args) < 1 {
-		return nil, errors.New("missing required arguments")
-	}
+func (rc *Cache) do(commandName string, args ...interface{}) (interface{}, error) {
 	args[0] = rc.associate(args[0])
 	c := rc.p.Get()
-	defer c.Close()
+	defer func() {
+		_ = c.Close()
+	}()
 
-	return c.Do(commandName, args...)
+	reply, err := c.Do(commandName, args...)
+	if err != nil {
+		return nil, berror.Wrapf(err, cache.RedisCacheCurdFailed,
+			"could not execute this command: %s", commandName)
+	}
+
+	return reply, nil
 }
 
 // associate with config key.
@@ -95,7 +100,9 @@ func (rc *Cache) Get(ctx context.Context, key string) (interface{}, error) {
 // GetMulti gets cache from redis.
 func (rc *Cache) GetMulti(ctx context.Context, keys []string) ([]interface{}, error) {
 	c := rc.p.Get()
-	defer c.Close()
+	defer func() {
+		_ = c.Close()
+	}()
 	var args []interface{}
 	for _, key := range keys {
 		args = append(args, rc.associate(key))
@@ -137,13 +144,16 @@ func (rc *Cache) Decr(ctx context.Context, key string) error {
 }
 
 // ClearAll deletes all cache in the redis collection
+// Be careful about this method, because it scans all keys and the delete them one by one
 func (rc *Cache) ClearAll(context.Context) error {
 	cachedKeys, err := rc.Scan(rc.key + ":*")
 	if err != nil {
 		return err
 	}
 	c := rc.p.Get()
-	defer c.Close()
+	defer func() {
+		_ = c.Close()
+	}()
 	for _, str := range cachedKeys {
 		if _, err = c.Do("DEL", str); err != nil {
 			return err
@@ -155,7 +165,9 @@ func (rc *Cache) ClearAll(context.Context) error {
 // Scan scans all keys matching a given pattern.
 func (rc *Cache) Scan(pattern string) (keys []string, err error) {
 	c := rc.p.Get()
-	defer c.Close()
+	defer func() {
+		_ = c.Close()
+	}()
 	var (
 		cursor uint64 = 0 // start
 		result []interface{}
@@ -186,13 +198,16 @@ func (rc *Cache) Scan(pattern string) (keys []string, err error) {
 // Cached items in redis are stored forever, no garbage collection happens
 func (rc *Cache) StartAndGC(config string) error {
 	var cf map[string]string
-	json.Unmarshal([]byte(config), &cf)
+	err := json.Unmarshal([]byte(config), &cf)
+	if err != nil {
+		return berror.Wrapf(err, cache.InvalidRedisCacheCfg, "could not unmarshal the config: %s", config)
+	}
 
 	if _, ok := cf["key"]; !ok {
 		cf["key"] = DefaultKey
 	}
 	if _, ok := cf["conn"]; !ok {
-		return errors.New("config has no conn key")
+		return berror.Wrapf(err, cache.InvalidRedisCacheCfg, "config missing conn field: %s", config)
 	}
 
 	// Format redis://<password>@<host>:<port>
@@ -229,9 +244,16 @@ func (rc *Cache) StartAndGC(config string) error {
 	rc.connectInit()
 
 	c := rc.p.Get()
-	defer c.Close()
+	defer func() {
+		_ = c.Close()
+	}()
 
-	return c.Err()
+	// test connection
+	if err = c.Err(); err != nil {
+		return berror.Wrapf(err, cache.InvalidConnection,
+			"can not connect to remote redis server, please check the connection info and network state: %s", config)
+	}
+	return nil
 }
 
 // connect to redis.
@@ -239,19 +261,20 @@ func (rc *Cache) connectInit() {
 	dialFunc := func() (c redis.Conn, err error) {
 		c, err = redis.Dial("tcp", rc.conninfo)
 		if err != nil {
-			return nil, err
+			return nil, berror.Wrapf(err, cache.DialFailed,
+				"could not dial to remote server: %s ", rc.conninfo)
 		}
 
 		if rc.password != "" {
-			if _, err := c.Do("AUTH", rc.password); err != nil {
-				c.Close()
+			if _, err = c.Do("AUTH", rc.password); err != nil {
+				_ = c.Close()
 				return nil, err
 			}
 		}
 
 		_, selecterr := c.Do("SELECT", rc.dbNum)
 		if selecterr != nil {
-			c.Close()
+			_ = c.Close()
 			return nil, selecterr
 		}
 		return
diff --git a/client/cache/ssdb/ssdb.go b/client/cache/ssdb/ssdb.go
index f637d2ab..e715d07f 100644
--- a/client/cache/ssdb/ssdb.go
+++ b/client/cache/ssdb/ssdb.go
@@ -3,7 +3,6 @@ package ssdb
 import (
 	"context"
 	"encoding/json"
-	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -12,6 +11,7 @@ import (
 	"github.com/ssdb/gossdb/ssdb"
 
 	"github.com/beego/beego/v2/client/cache"
+	"github.com/beego/beego/v2/core/berror"
 )
 
 // Cache SSDB adapter
@@ -27,31 +27,21 @@ func NewSsdbCache() cache.Cache {
 
 // Get gets a key's value from memcache.
 func (rc *Cache) Get(ctx context.Context, key string) (interface{}, error) {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return nil, err
-		}
-	}
 	value, err := rc.conn.Get(key)
 	if err == nil {
 		return value, nil
 	}
-	return nil, err
+	return nil, berror.Wrapf(err, cache.SsdbCacheCurdFailed, "could not get value, key: %s", key)
 }
 
 // GetMulti gets one or keys values from ssdb.
 func (rc *Cache) GetMulti(ctx context.Context, keys []string) ([]interface{}, error) {
 	size := len(keys)
 	values := make([]interface{}, size)
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return values, err
-		}
-	}
 
 	res, err := rc.conn.Do("multi_get", keys)
 	if err != nil {
-		return values, err
+		return values, berror.Wrapf(err, cache.SsdbCacheCurdFailed, "multi_get failed, key: %v", keys)
 	}
 
 	resSize := len(res)
@@ -70,7 +60,7 @@ func (rc *Cache) GetMulti(ctx context.Context, keys []string) ([]interface{}, er
 	}
 
 	if len(keysErr) != 0 {
-		return values, fmt.Errorf(strings.Join(keysErr, "; "))
+		return values, berror.Error(cache.MultiGetFailed, strings.Join(keysErr, "; "))
 	}
 
 	return values, nil
@@ -78,26 +68,16 @@ func (rc *Cache) GetMulti(ctx context.Context, keys []string) ([]interface{}, er
 
 // DelMulti deletes one or more keys from memcache
 func (rc *Cache) DelMulti(keys []string) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	_, err := rc.conn.Do("multi_del", keys)
-	return err
+	return berror.Wrapf(err, cache.SsdbCacheCurdFailed, "multi_del failed: %v", keys)
 }
 
 // Put puts value into memcache.
 // value:  must be of type string
 func (rc *Cache) Put(ctx context.Context, key string, val interface{}, timeout time.Duration) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	v, ok := val.(string)
 	if !ok {
-		return errors.New("value must string")
+		return berror.Errorf(cache.InvalidSsdbCacheValue, "value must be string: %v", val)
 	}
 	var resp []string
 	var err error
@@ -108,57 +88,37 @@ func (rc *Cache) Put(ctx context.Context, key string, val interface{}, timeout t
 		resp, err = rc.conn.Do("setx", key, v, ttl)
 	}
 	if err != nil {
-		return err
+		return berror.Wrapf(err, cache.SsdbCacheCurdFailed, "set or setx failed, key: %s", key)
 	}
 	if len(resp) == 2 && resp[0] == "ok" {
 		return nil
 	}
-	return errors.New("bad response")
+	return berror.Errorf(cache.SsdbBadResponse, "the response from SSDB server is invalid: %v", resp)
 }
 
 // Delete deletes a value in memcache.
 func (rc *Cache) Delete(ctx context.Context, key string) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	_, err := rc.conn.Del(key)
-	return err
+	return berror.Wrapf(err, cache.SsdbCacheCurdFailed, "del failed: %s", key)
 }
 
 // Incr increases a key's counter.
 func (rc *Cache) Incr(ctx context.Context, key string) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	_, err := rc.conn.Do("incr", key, 1)
-	return err
+	return berror.Wrapf(err, cache.SsdbCacheCurdFailed, "increase failed: %s", key)
 }
 
 // Decr decrements a key's counter.
 func (rc *Cache) Decr(ctx context.Context, key string) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	_, err := rc.conn.Do("incr", key, -1)
-	return err
+	return berror.Wrapf(err, cache.SsdbCacheCurdFailed, "decrease failed: %s", key)
 }
 
 // IsExist checks if a key exists in memcache.
 func (rc *Cache) IsExist(ctx context.Context, key string) (bool, error) {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return false, err
-		}
-	}
 	resp, err := rc.conn.Do("exists", key)
 	if err != nil {
-		return false, err
+		return false, berror.Wrapf(err, cache.SsdbCacheCurdFailed, "exists failed: %s", key)
 	}
 	if len(resp) == 2 && resp[1] == "1" {
 		return true, nil
@@ -167,13 +127,9 @@ func (rc *Cache) IsExist(ctx context.Context, key string) (bool, error) {
 
 }
 
-// ClearAll clears all cached items in memcache.
+// ClearAll clears all cached items in ssdb.
+// If there are many keys, this method may spent much time.
 func (rc *Cache) ClearAll(context.Context) error {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
 	keyStart, keyEnd, limit := "", "", 50
 	resp, err := rc.Scan(keyStart, keyEnd, limit)
 	for err == nil {
@@ -187,21 +143,16 @@ func (rc *Cache) ClearAll(context.Context) error {
 		}
 		_, e := rc.conn.Do("multi_del", keys)
 		if e != nil {
-			return e
+			return berror.Wrapf(e, cache.SsdbCacheCurdFailed, "multi_del failed: %v", keys)
 		}
 		keyStart = resp[size-2]
 		resp, err = rc.Scan(keyStart, keyEnd, limit)
 	}
-	return err
+	return berror.Wrap(err, cache.SsdbCacheCurdFailed, "scan failed")
 }
 
 // Scan key all cached in ssdb.
 func (rc *Cache) Scan(keyStart string, keyEnd string, limit int) ([]string, error) {
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return nil, err
-		}
-	}
 	resp, err := rc.conn.Do("scan", keyStart, keyEnd, limit)
 	if err != nil {
 		return nil, err
@@ -214,30 +165,36 @@ func (rc *Cache) Scan(keyStart string, keyEnd string, limit int) ([]string, erro
 // If an error occurs during connection, an error is returned
 func (rc *Cache) StartAndGC(config string) error {
 	var cf map[string]string
-	json.Unmarshal([]byte(config), &cf)
+	err := json.Unmarshal([]byte(config), &cf)
+	if err != nil {
+		return berror.Wrapf(err, cache.InvalidSsdbCacheCfg,
+			"unmarshal this config failed, it must be a valid json string: %s", config)
+	}
 	if _, ok := cf["conn"]; !ok {
-		return errors.New("config has no conn key")
+		return berror.Wrapf(err, cache.InvalidSsdbCacheCfg,
+			"Missing conn field: %s", config)
 	}
 	rc.conninfo = strings.Split(cf["conn"], ";")
-	if rc.conn == nil {
-		if err := rc.connectInit(); err != nil {
-			return err
-		}
-	}
-	return nil
+	return rc.connectInit()
 }
 
 // connect to memcache and keep the connection.
 func (rc *Cache) connectInit() error {
 	conninfoArray := strings.Split(rc.conninfo[0], ":")
+	if len(conninfoArray) < 2 {
+		return berror.Errorf(cache.InvalidSsdbCacheCfg, "The value of conn should be host:port: %s", rc.conninfo[0])
+	}
 	host := conninfoArray[0]
 	port, e := strconv.Atoi(conninfoArray[1])
 	if e != nil {
-		return e
+		return berror.Errorf(cache.InvalidSsdbCacheCfg, "Port is invalid. It must be integer, %s", rc.conninfo[0])
 	}
 	var err error
-	rc.conn, err = ssdb.Connect(host, port)
-	return err
+	if rc.conn, err = ssdb.Connect(host, port); err != nil {
+		return berror.Wrapf(err, cache.InvalidConnection,
+			"could not connect to SSDB, please check your connection info, network and firewall: %s", rc.conninfo[0])
+	}
+	return nil
 }
 
 func init() {
diff --git a/client/cache/ssdb/ssdb_test.go b/client/cache/ssdb/ssdb_test.go
index e08ed573..fea755f4 100644
--- a/client/cache/ssdb/ssdb_test.go
+++ b/client/cache/ssdb/ssdb_test.go
@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"os"
 	"strconv"
+	"strings"
 	"testing"
 	"time"
 
@@ -89,7 +90,7 @@ func TestSsdbcacheCache(t *testing.T) {
 	assert.Nil(t,  vv[1])
 
 	assert.NotNil(t, err)
-	assert.Equal(t, "key [ssdb11] error: key not exist", err.Error())
+	assert.True(t, strings.Contains(err.Error(), "key not exist"))
 
 	// test clear all done
 	assert.Nil(t, ssdb.ClearAll(context.Background()))