diff --git a/examples/agent.lua b/examples/agent.lua
index 06db1108..c4cfaf27 100644
--- a/examples/agent.lua
+++ b/examples/agent.lua
@@ -1,6 +1,6 @@
 local skynet = require "skynet"
 local netpack = require "netpack"
-local socket = require "socket"
+local socket = require "skynet.socket"
 local sproto = require "sproto"
 local sprotoloader = require "sprotoloader"
 
diff --git a/examples/simpleweb.lua b/examples/simpleweb.lua
index 5d38dfb1..283b7e91 100644
--- a/examples/simpleweb.lua
+++ b/examples/simpleweb.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local socket = require "socket"
+local socket = require "skynet.socket"
 local httpd = require "http.httpd"
 local sockethelper = require "http.sockethelper"
 local urllib = require "http.url"
diff --git a/lualib/mongo.lua b/lualib/skynet/db/mongo.lua
similarity index 99%
rename from lualib/mongo.lua
rename to lualib/skynet/db/mongo.lua
index 393f4334..d25dc8fb 100644
--- a/lualib/mongo.lua
+++ b/lualib/skynet/db/mongo.lua
@@ -1,6 +1,6 @@
 local bson = require "bson"
-local socket = require "socket"
-local socketchannel	= require "socketchannel"
+local socket = require "skynet.socket"
+local socketchannel	= require "skynet.socketchannel"
 local skynet = require "skynet"
 local driver = require "mongo.driver"
 local md5 =	require	"md5"
diff --git a/lualib/mysql.lua b/lualib/skynet/db/mysql.lua
similarity index 99%
rename from lualib/mysql.lua
rename to lualib/skynet/db/mysql.lua
index afa76425..e6f8a347 100644
--- a/lualib/mysql.lua
+++ b/lualib/skynet/db/mysql.lua
@@ -4,7 +4,7 @@
 -- The license is under the BSD license.
 -- Modified by Cloud Wu (remove bit32 for lua 5.3)
 
-local socketchannel = require "socketchannel"
+local socketchannel = require "skynet.socketchannel"
 local mysqlaux = require "mysqlaux.c"
 local crypt = require "crypt"
 
diff --git a/lualib/redis.lua b/lualib/skynet/db/redis.lua
similarity index 98%
rename from lualib/redis.lua
rename to lualib/skynet/db/redis.lua
index 949023a2..e838a978 100644
--- a/lualib/redis.lua
+++ b/lualib/skynet/db/redis.lua
@@ -1,6 +1,6 @@
 local skynet = require "skynet"
-local socket = require "socket"
-local socketchannel = require "socketchannel"
+local socket = require "skynet.socket"
+local socketchannel = require "skynet.socketchannel"
 
 local table = table
 local string = string
diff --git a/lualib/dns.lua b/lualib/skynet/dns.lua
similarity index 99%
rename from lualib/dns.lua
rename to lualib/skynet/dns.lua
index 76f363f0..0b96f214 100644
--- a/lualib/dns.lua
+++ b/lualib/skynet/dns.lua
@@ -65,7 +65,7 @@
 --]]
 
 local skynet = require "skynet"
-local socket = require "socket"
+local socket = require "skynet.socket"
 
 local MAX_DOMAIN_LEN = 1024
 local MAX_LABEL_LEN = 63
diff --git a/lualib/socket.lua b/lualib/skynet/socket.lua
similarity index 100%
rename from lualib/socket.lua
rename to lualib/skynet/socket.lua
diff --git a/lualib/socketchannel.lua b/lualib/skynet/socketchannel.lua
similarity index 99%
rename from lualib/socketchannel.lua
rename to lualib/skynet/socketchannel.lua
index fc3c246e..751a29a6 100644
--- a/lualib/socketchannel.lua
+++ b/lualib/skynet/socketchannel.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local socket = require "socket"
+local socket = require "skynet.socket"
 local socketdriver = require "socketdriver"
 
 -- channel support auto reconnect , and capture socket error in request/response transaction
diff --git a/test/testdns.lua b/test/testdns.lua
index 1d767ce0..01ac414a 100644
--- a/test/testdns.lua
+++ b/test/testdns.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local dns = require "dns"
+local dns = require "skynet.dns"
 
 skynet.start(function()
 	print("nameserver:", dns.server())	-- set nameserver
diff --git a/test/testhttp.lua b/test/testhttp.lua
index 4098b629..f9524930 100644
--- a/test/testhttp.lua
+++ b/test/testhttp.lua
@@ -1,6 +1,6 @@
 local skynet = require "skynet"
 local httpc = require "http.httpc"
-local dns = require "dns"
+local dns = require "skynet.dns"
 
 local function main()
 	httpc.dns()	-- set dns server
diff --git a/test/testmemlimit.lua b/test/testmemlimit.lua
index 5c0c10d5..c1a7e63e 100644
--- a/test/testmemlimit.lua
+++ b/test/testmemlimit.lua
@@ -1,6 +1,15 @@
 local skynet = require "skynet"
 
-local names = {"cluster", "dns", "mongo", "mysql", "redis", "sharedata", "socket", "sproto"}
+local names = {
+	"cluster",
+	"skynet.db.dns",
+	"skynet.db.mongo",
+	"skynet.db.mysql",
+	"skynet.db.redis",
+	"sharedata",
+	"skynet.socket",
+	"sproto"
+}
 
 -- set sandbox memory limit to 1M, must set here (at start, out of skynet.start)
 skynet.memlimit(1 * 1024 * 1024)
diff --git a/test/testmongodb.lua b/test/testmongodb.lua
index 06e2691c..138a970b 100644
--- a/test/testmongodb.lua
+++ b/test/testmongodb.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local mongo = require "mongo"
+local mongo = require "skynet.db.mongo"
 local bson = require "bson"
 
 local host, db_name = ...
diff --git a/test/testmysql.lua b/test/testmysql.lua
index e8b420aa..0b11aeb7 100644
--- a/test/testmysql.lua
+++ b/test/testmysql.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local mysql = require "mysql"
+local mysql = require "skynet.db.mysql"
 
 local function dump(obj)
     local getIndent, quoteStr, wrapKey, wrapVal, dumpObj
diff --git a/test/testpipeline.lua b/test/testpipeline.lua
index d5c57c8d..b2eea2f1 100644
--- a/test/testpipeline.lua
+++ b/test/testpipeline.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local redis = require "redis"
+local redis = require "skynet.db.redis"
 
 local conf = {
 	host = "127.0.0.1",
diff --git a/test/testredis.lua b/test/testredis.lua
index 31a13c5a..1b692e1f 100644
--- a/test/testredis.lua
+++ b/test/testredis.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local redis = require "redis"
+local redis = require "skynet.db.redis"
 
 local conf = {
 	host = "127.0.0.1" ,
diff --git a/test/testredis2.lua b/test/testredis2.lua
index f12d8100..d3d50961 100644
--- a/test/testredis2.lua
+++ b/test/testredis2.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local redis  = require "redis"
+local redis  = require "skynet.db.redis"
 
 local db
 
diff --git a/test/testsocket.lua b/test/testsocket.lua
index 3893cd61..179df1a8 100644
--- a/test/testsocket.lua
+++ b/test/testsocket.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local socket = require "socket"
+local socket = require "skynet.socket"
 
 local mode , id = ...
 
diff --git a/test/testudp.lua b/test/testudp.lua
index fb8f7109..e62f4067 100644
--- a/test/testudp.lua
+++ b/test/testudp.lua
@@ -1,5 +1,5 @@
 local skynet = require "skynet"
-local socket = require "socket"
+local socket = require "skynet.socket"
 
 local function server()
 	local host