diff --git a/Makefile b/Makefile
index 938949d..5d2d27f 100644
--- a/Makefile
+++ b/Makefile
@@ -5,7 +5,7 @@ LUA_INCLUDE_DIR ?= $(PREFIX)/include
 LUA_LIB_DIR ?=     $(PREFIX)/lib/lua/$(LUA_VERSION)
 INSTALL ?= install
 
-.PHONY: all test install
+.PHONY: all test install stress_test clean
 
 all: ;
 
@@ -17,3 +17,8 @@ install: all
 test: all
 	PATH=$(OPENRESTY_PREFIX)/nginx/sbin:$$PATH prove -I../test-nginx/lib -r t
 
+stress_test:
+	make -C stress_test ITERATOR=8
+
+clean:
+	make -C stress_test clean
diff --git a/stress_test/Makefile b/stress_test/Makefile
new file mode 100644
index 0000000..9b98f3e
--- /dev/null
+++ b/stress_test/Makefile
@@ -0,0 +1,56 @@
+.PHONY: all clean
+default : all
+
+TARGZ_INPUTS := http://nginx.org/download/nginx-1.7.9.tar.gz \
+                https://github.com/cloudflare/lua-aho-corasick/archive/46f1a4146b8b9021b8df25a39572d1242ece899d.tar.gz
+
+LOCALFILES := $(foreach f, $(TARGZ_INPUTS), $(call notdir, $f))
+KEYFILES := $(patsubst %.tar.gz, %.key, $(LOCALFILES))
+TMP_FILE := a.tmp
+TMP_DIR := tmp
+
+ITERATOR := 4
+LUAJIT := luajit
+
+######################################################################
+#
+#   Download *.tar.gz files from Internet
+#
+######################################################################
+#
+define DOWNLOAD
+$$(notdir $(1)) :
+	wget $(1) -O $$@
+endef
+$(foreach k,$(TARGZ_INPUTS),$(eval $(call DOWNLOAD,$(k))))
+
+######################################################################
+#
+#   generate files of keys from ther *.tar.gz downloaded from Internet
+#
+######################################################################
+#
+define GEN_KEY
+$$(patsubst %.tar.gz, %.key, $(1)): $(1)
+	rm -rf $(TMP_DIR); \
+	mkdir $(TMP_DIR); \
+	tar -C $(TMP_DIR) -zxvf $(1); \
+	find $(TMP_DIR) -type f -exec cat {} \; > $(TMP_FILE); \
+	./key.py $(TMP_FILE) > $$@
+	rm -rf $(TMP_DIR) $(TMP_FILE)
+endef
+$(foreach k,$(LOCALFILES),$(eval $(call GEN_KEY,$(k))))
+
+all:
+	@for f in $(KEYFILES); do \
+		echo "Testing with $${f}..."; \
+		for i in `seq $(ITERATOR)`; do \
+			echo "Iteration $${i}"; \
+			rm -f $${f}; \
+            $(MAKE) $${f} > /dev/null; \
+            $(LUAJIT) ./test.lua $${f}; \
+		done; \
+	done
+
+clean:
+	rm -rf $(LOCALFILES) $(KEYFILES) $(TMP_FILE) $(TMP_DIR)
diff --git a/stress_test/key.py b/stress_test/key.py
new file mode 100755
index 0000000..e8913da
--- /dev/null
+++ b/stress_test/key.py
@@ -0,0 +1,30 @@
+#!/usr/bin/env python
+
+import random
+import fileinput
+import sys
+import os
+
+def print_usage(prog):
+    print ("%s [list of files]" % prog)
+    return
+
+if len(sys.argv) == 1:
+    print_usage(sys.argv[0])
+    sys.exit(1)
+
+for f in sys.argv[1:]:
+    if not os.access(f, os.R_OK):
+        print "file '%s' is not readable" % f
+        sys.exit(1)
+
+for line in fileinput.input():
+    columns = line.split()
+    cn = len(columns)
+    if cn > 0:
+        col_idx = int(random.random() * cn + 0.5)
+        if col_idx == cn:
+            col_idx = 0
+        print columns[col_idx]
+
+sys.exit(0)
diff --git a/stress_test/test.lua b/stress_test/test.lua
new file mode 100644
index 0000000..c89450e
--- /dev/null
+++ b/stress_test/test.lua
@@ -0,0 +1,67 @@
+local argv = {...}
+if #argv ~= 1 then
+    print ("Usage test.lua key-file")
+    os.exit(1)
+end
+
+local keyfile = io.open(argv[1])
+if not keyfile then
+    io.write(string.format("Fail to open key file '%s'\n", argv[1]))
+    os.exit(1)
+end
+
+ngx = {}
+ngx.new = function() return os.time() end
+
+package.path =  "../lib/resty/?.lua;../lib/resty/lrucache/?.lua;" .. package.path
+lruffi = require "pureffi"
+lru = require "lrucache"
+
+local key_num = 128
+local lru_inst = lru.new(key_num)
+local lruffi_inst = lruffi.new(key_num, 0.5)
+
+local key_vect = {}
+local key_idx = 0
+local key_cnt = 0
+
+local function compare()
+    for i = 1, key_idx do
+        local key = key_vect[i]
+        local val1 = lru_inst:get(key)
+        local val2 = lruffi_inst:get(key)
+        -- print(key, val1, val2)
+        if val1 ~= val2 then
+            io.write(
+                string.format("disagree on key '%s', values are %d vs %d\n",
+                              key, val1, val2))
+            os.exit(1)
+        end
+    end
+end
+
+local function main()
+    for line in keyfile:lines() do
+
+        lru_inst:set(line, key_cnt)
+        lruffi_inst:set(line, key_cnt)
+
+        key_cnt = key_cnt + 1
+        key_idx = key_idx + 1
+        key_vect[key_idx] = line
+
+        if key_idx == key_num then
+            compare()
+            for i = 1, key_idx do
+                key_vect[i] = nil
+            end
+            key_idx = 0
+        end
+    end
+
+    compare()
+end
+
+main()
+
+os.exit(0)