diff --git a/compile_thrift.py b/compile_thrift.py
index a0a2756bbb..9b0c037edc 100755
--- a/compile_thrift.py
+++ b/compile_thrift.py
@@ -79,7 +79,7 @@
     },
     {
         "name": "simple_kv",
-        "path": "src/apps/skv"
+        "path": "src/dist/replication/storage_engine/simple_kv"
     },
     {
         "name": "cli",
diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 194779059b..2db60e1920 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -3,5 +3,4 @@ if(UNIX)
 endif()
 add_subdirectory(core)
 add_subdirectory(dist)
-add_subdirectory(apps)
 add_subdirectory(tests)
diff --git a/src/apps/CMakeLists.txt b/src/apps/CMakeLists.txt
deleted file mode 100644
index 5bf81603b0..0000000000
--- a/src/apps/CMakeLists.txt
+++ /dev/null
@@ -1 +0,0 @@
-add_subdirectory(skv)
diff --git a/src/apps/skv/multi-meta.sh b/src/apps/skv/multi-meta.sh
deleted file mode 100755
index 797c383d56..0000000000
--- a/src/apps/skv/multi-meta.sh
+++ /dev/null
@@ -1,166 +0,0 @@
-#!/bin/bash
-
-exe=dsn.replication.simple_kv
-cfg=config-zk.ini
-start_dir=run
-meta_count=1
-replica_count=3
-
-function run_app()
-{
-    cd $start_dir
-    local app_dir=$1$2
-    if [ ! -d $app_dir ]; then
-        mkdir $app_dir
-    fi
-
-    cd $app_dir
-    if [ ! -f $exe ]; then
-        cp ../$exe ../$cfg ./
-    fi
-    ./$exe $cfg -app_list $1@$2 > output.log 2>&1 &
-    cd ../..
-}
-
-function kill_app()
-{
-    ps aux | grep $exe | grep $cfg | grep $1@$2 | awk '{print $2}' | xargs kill -9
-}
-
-function start_all_apps()
-{
-    for ((i=1; i<=$meta_count; ++i)); do
-        run_app meta $i
-    done
-    for ((i=1; i<=$replica_count; ++i)); do
-        run_app replica $i
-    done
-}
-
-function stop_all_apps()
-{
-    ps aux | grep $exe | grep $cfg | awk '{print $2}' | xargs kill -9
-}
-
-function count_core_file()
-{
-    local target_dir=$start_dir/$1$2
-    if [ -d $target_dir ]; then
-        echo `ls $target_dir | grep core | wc -l`
-    else
-        echo "0"
-    fi
-}
-
-function core_file_detect()
-{
-    for ((i=1; i<=$meta_count; ++i)); do
-        if [ `count_core_file meta $i` -ne "0" ]; then
-            echo meta$i
-            return
-        fi
-    done
-    for ((i=1; i<=$replica_count; ++i)); do
-        if [ `count_core_file replica $i` -ne "0" ]; then
-            echo replica$i
-            return
-        fi
-    done
-    echo 0
-}
-
-function round_kill_meta()
-{
-    local i=0
-    local meta_id
-    while [ `core_file_detect` == 0 ]; do
-        meta_id=$[ $i+1 ]
-        echo "kill meta $meta_id"
-        kill_app meta $meta_id
-        sleep 30
-        echo "start meta $meta_id"
-        run_app meta $meta_id
-        i=$[ ($i+1)%$meta_count ]
-        sleep 60
-    done
-    echo "core file detected, exit"
-}
-
-function random_kill_replica()
-{
-    local random_replica_id
-    local core_result=0
-
-    while [ $core_result == 0 ]; do
-        sleep 30
-        random_replica_id=$[ $RANDOM%$replica_count+1 ]
-        echo "kill replica $reandom_replica_id"
-        kill_app replica $random_replica_id
-        sleep 10
-        echo "restart replica $random_replica_id"
-        run_app replica $random_replica_id
-        core_result=`core_file_detect`
-    done
-
-    echo "core file detect in dir $core_result"
-    sleep 2
-    stop_all_apps
-}
-
-function poll_core()
-{
-    local core_result=0
-    while [ $core_result == 0 ]; do
-        sleep 1
-        core_result=`core_file_detect`
-    done
-    echo "core file detect in dir: $core_result"
-    sleep 2
-    stop_all_apps
-}
-
-if [ ! -d $start_dir ]; then
-    mkdir $start_dir
-fi
-
-if [ ! -f $start_dir/$exe ]; then
-    cp $exe $cfg $start_dir
-fi
-
-case $1 in
-    start)
-        start_all_apps ;;
-    stop)
-        stop_all_apps ;;
-    clear)
-        rm -rf run ;;
-    meta_test)
-        round_kill_meta ;;
-    replica_test)
-        random_kill_replica ;;
-    start_svc)
-        apps_count=$meta_count
-        if [ $2 == "replica" ]; then
-            apps_count=$replica_count
-        fi
-
-        if [ $# -eq 2 ]; then
-            for ((index=1; index<=$apps_count; ++index)); do
-                run_app $2 $index
-            done
-        elif [ $# -eq 3 ]; then
-            run_app $2 $3
-        fi
-        ;;
-    check_svc)
-        poll_core ;;
-    kill_svc)
-        if [ $# -eq 2 ]; then
-            ps aux | grep $exe | grep $cfg | grep $2 | awk '{print $2}' | xargs kill -9
-        elif [ $# -eq 3 ]; then
-            kill_app $2 $3
-        fi
-        ;;
-    list)
-        ps aux | grep $exe | grep $cfg
-esac
diff --git a/src/apps/skv/simple_kv.thrift.annotations b/src/apps/skv/simple_kv.thrift.annotations
deleted file mode 100644
index e06a3c06bb..0000000000
--- a/src/apps/skv/simple_kv.thrift.annotations
+++ /dev/null
@@ -1,14 +0,0 @@
-; annotation format
-;[type.name[[.subname]...]]
-;key = vlaue
-
-[service.simple_kv]
-stateful = true ; simple_kv is a stateful service
-
-[function.simple_kv.write]
-write = true  ; simple_kv.write is a write function
-
-[function.simple_kv.append]
-write = true
-
-
diff --git a/src/apps/skv/test-n.cmd b/src/apps/skv/test-n.cmd
deleted file mode 100644
index dd5f57b4fd..0000000000
--- a/src/apps/skv/test-n.cmd
+++ /dev/null
@@ -1,8 +0,0 @@
-echo OFF
-for /l %%x in (11, 1, 20) do (
-	echo start test instance %%x 
-	mkdir test-%%x
-	cd test-%%x	
-	start ..\dsn.replication.simple_kv.exe ..\config-n.ini
-	cd ..
-)
diff --git a/src/apps/skv/test.cmd b/src/apps/skv/test.cmd
deleted file mode 100644
index dece6b8163..0000000000
--- a/src/apps/skv/test.cmd
+++ /dev/null
@@ -1,15 +0,0 @@
-@echo OFF
-mkdir test
-copy /Y *.ini .\test
-copy /Y *.exe .\test
-copy /Y *.pdb .\test
-copy /Y *.cmd .\test
-copy /Y ..\..\Debug\*.dll .\test
-	
-for /l %%x in (1, 1, 42) do (
-	echo start test instance %%x 
-	mkdir test-%%x
-	cd test-%%x	
-	start "test-%%x" /LOW ../test/dsn.replication.simple_kv.exe ../test/config.ini
-	cd ..
-)
diff --git a/src/apps/skv/vconfig.ini b/src/apps/skv/vconfig.ini
deleted file mode 100644
index 9c9cebd34c..0000000000
--- a/src/apps/skv/vconfig.ini
+++ /dev/null
@@ -1,165 +0,0 @@
-[apps..default]
-run = true
-count = 1
-;network.client.RPC_CHANNEL_TCP = dsn::tools::sim_network_provider, 65536
-;network.client.RPC_CHANNEL_UDP = dsn::tools::sim_network_provider, 65536
-;network.server.0.RPC_CHANNEL_TCP = dsn::tools::sim_network_provider, 65536
-;network.server.0.RPC_CHANNEL_UDP = dsn::tools::sim_network_provider, 65536
-
-[apps.meta]
-type = meta
-arguments = 
-ports = %meta_port%
-run = true
-count = 1
-pools = THREAD_POOL_DEFAULT,THREAD_POOL_META_SERVER,THREAD_POOL_FD,THREAD_POOL_META_STATE
-
-[apps.replica]
-type = replica
-arguments = 
-ports = %replica_port%
-run = true
-count = 3
-pools = THREAD_POOL_DEFAULT,THREAD_POOL_REPLICATION_LONG,THREAD_POOL_REPLICATION,THREAD_POOL_FD,THREAD_POOL_LOCAL_APP
-
-[apps.client]
-type = client
-arguments = dsn://mycluster/simple_kv.instance0
-run = true
-count = 1
-pools = THREAD_POOL_DEFAULT
-
-[apps.client.perf.test]
-type = client.perf.test
-arguments = dsn://mycluster/simple_kv.instance0
-run = true
-count = 1
-pools = THREAD_POOL_DEFAULT
-
-
-[core]
-
-
-;tool = simulator
-tool = nativerun
-;toollets = tracer
-;toollets = fault_injector
-;toollets = tracer, fault_injector
-toollets = tracer, profiler, fault_injector
-;toollets = profiler, fault_injector
-pause_on_start = false
-
-;logging_start_level = LOG_LEVEL_WARNING
-;logging_factory_name = dsn::tools::screen_logger
-;aio_factory_name = dsn::tools::empty_aio_provider
-
-[tools.simulator]
-random_seed = 0
-;min_message_delay_microseconds = 0
-;max_message_delay_microseconds = 0
-
-[network]
-; how many network threads for network library(used by asio)
-io_service_worker_count = 2
-
-; specification for each thread pool
-
-[threadpool..default]
-worker_count = 2
-worker_priority = THREAD_xPRIORITY_LOWEST
-
-[threadpool.THREAD_POOL_DEFAULT]
-partitioned = false
-worker_priority = THREAD_xPRIORITY_LOWEST
-
-[threadpool.THREAD_POOL_REPLICATION]
-partitioned = true
-worker_priority = THREAD_xPRIORITY_LOWEST
-
-[threadpool.THREAD_POOL_META_STATE]
-worker_count = 1
-
-[task..default]
-is_trace = true
-is_profile = true
-allow_inline = false
-rpc_call_channel = RPC_CHANNEL_TCP
-rpc_message_header_format = dsn
-rpc_timeout_milliseconds = 5000
-
-disk_write_fail_ratio = 0.0
-disk_read_fail_ratio = 0.00001
-
-
-[task.LPC_CHECKPOINT_REPLICA]
-execution_extra_delay_us_max = 10000000
-
-[task.LPC_LEARN_REMOTE_DELTA_FILES]
-execution_extra_delay_us_max = 10000000
-
-[task.LPC_AIO_IMMEDIATE_CALLBACK]
-is_trace = false
-allow_inline = false
-disk_write_fail_ratio = 0.0
-
-[task.RPC_CM_QUERY_PARTITION_CONFIG_BY_INDEX]
-is_trace = false
-
-[task.LPC_RPC_TIMEOUT]
-is_trace = false
-
-[task.RPC_FD_FAILURE_DETECTOR_PING]
-is_trace = false
-rpc_call_channel = RPC_CHANNEL_UDP
-rpc_message_crc_required = true
-
-[task.RPC_FD_FAILURE_DETECTOR_PING_ACK]
-is_trace = false
-rpc_call_channel = RPC_CHANNEL_UDP
-rpc_message_crc_required = true
-
-[task.LPC_BEACON_CHECK]
-is_trace = false
-
-[uri-resolver.dsn://mycluster]
-factory = partition_resolver_simple
-arguments = localhost:%meta_port%
-
-[meta_server]
-server_list = localhost:%meta_port%
-
-[replication.app]
-app_name = simple_kv.instance0
-app_type = simple_kv
-partition_count = 1
-max_replica_count = 3
-
-[replication]
-
-prepare_timeout_ms_for_secondaries = 10000
-log_enable_shared_prepare = true
-
-learn_timeout_ms = 30000
-staleness_for_commit = 20
-staleness_for_start_prepare_for_potential_secondary = 110
-mutation_max_size_mb = 15
-mutation_max_pending_time_ms = 20
-mutation_2pc_min_replica_count = 2
-
-prepare_list_max_size_mb = 250
-request_batch_disabled = false
-group_check_internal_ms = 100000
-group_check_disabled = false
-fd_disabled = false
-fd_check_interval_seconds = 5
-fd_beacon_interval_seconds = 3
-fd_lease_seconds = 14
-fd_grace_seconds = 15
-working_dir = .
-log_buffer_size_mb = 1
-log_pending_max_ms = 100
-log_file_size_mb = 32
-log_batch_write = true
-
-config_sync_interval_ms = 60000
-
diff --git a/src/apps/skv/vtest.cmd b/src/apps/skv/vtest.cmd
deleted file mode 100644
index a7f5aeca47..0000000000
--- a/src/apps/skv/vtest.cmd
+++ /dev/null
@@ -1,29 +0,0 @@
-@echo OFF
-mkdir test
-copy /Y *.ini .\test
-copy /Y *.exe .\test
-copy /Y *.pdb .\test
-copy /Y *.cmd .\test
-copy /Y *.dll .\test
-
-set replica_port=34801
-set meta_port=34601
-	
-SETLOCAL ENABLEDELAYEDEXPANSION
-
-for /l %%x in (1, 1, 20) do call :test %%x
-goto :eof
-
-:test
-	set x=%~n1
-	echo start test instance %x%
-	@mkdir test-%x%
-	cd test-%x%
-	set /a replica_port=!replica_port!+3
-	set /a meta_port=!meta_port!+3
-        set lcmd=../test/dsn.replication.simple_kv.exe ../test/vconfig.ini -cargs meta_port=!meta_port!;replica_port=!replica_port!
-	echo %lcmd%
-	start "test-%x%" /LOW %lcmd%
-	cd ..
-
-:eof
diff --git a/src/apps/skv/vtest.sh b/src/apps/skv/vtest.sh
deleted file mode 100755
index 8f9a8b178d..0000000000
--- a/src/apps/skv/vtest.sh
+++ /dev/null
@@ -1,75 +0,0 @@
-#!/bin/bash
-exe=dsn.replication.simple_kv
-cfg=vconfig.ini
-test_dir=test
-test_count=5
-
-function count_core_file()
-{
-    local target_dir=$test_dir/test-$1
-    if [ -d $target_dir ]; then
-        echo `ls $target_dir | grep core | wc -l`
-    else
-        echo "0"
-    fi
-}
-
-function core_file_detect()
-{
-    for ((i=1; i<=$test_count; ++i)); do
-        if [ `count_core_file $i` -ne "0" ]; then
-            echo $i
-            return
-        fi
-    done
-    echo 0
-}
-
-function run_test()
-{
-    mkdir $test_dir    
-    replica_port=34801
-    meta_port=34601
-    
-    cd $test_dir
-    for ((i=1; i<=$test_count; ++i)); do
-        echo start test instance $i
-        mkdir test-$i
-        cp ../$exe ../$cfg test-$i
-        cd test-$i
-        replica_port=$[ $replica_port+3 ]
-            meta_port=$[ $meta_port+3 ]
-        command="./dsn.replication.simple_kv vconfig.ini -cargs meta_port=$meta_port,replica_port=$replica_port"
-        echo $command
-        ulimit -c unlimited
-        $command > output.log 2>&1 &
-        cd ..
-    done
-    cd ..
-}
-
-function stop_all()
-{
-    ps aux | grep $exe | grep $cfg | awk '{print $2}' | xargs kill -9
-}
-
-function check_core()
-{
-    local check_result
-    while [ 0 -lt 1 ]; do
-        check_result=`core_file_detect`
-        if [ $check_result -ne "0" ]; then
-            echo "core file detect in $check_result"
-        fi
-        sleep 5
-    done
-}
-
-case $1 in 
-    start)
-        run_test ;;
-    stop)
-        stop_all ;;
-    check)
-        check_core ;;
-esac
diff --git a/src/dist/replication/CMakeLists.txt b/src/dist/replication/CMakeLists.txt
index 85c0e29a25..10ee12af9c 100644
--- a/src/dist/replication/CMakeLists.txt
+++ b/src/dist/replication/CMakeLists.txt
@@ -6,3 +6,4 @@ add_subdirectory(lib)
 add_subdirectory(global_checker)
 add_subdirectory(zookeeper)
 add_subdirectory(test)
+add_subdirectory(storage_engine)
diff --git a/src/dist/replication/storage_engine/CMakeLists.txt b/src/dist/replication/storage_engine/CMakeLists.txt
new file mode 100644
index 0000000000..ddbac4f45d
--- /dev/null
+++ b/src/dist/replication/storage_engine/CMakeLists.txt
@@ -0,0 +1 @@
+add_subdirectory(simple_kv)
diff --git a/src/apps/skv/CMakeLists.txt b/src/dist/replication/storage_engine/simple_kv/CMakeLists.txt
similarity index 95%
rename from src/apps/skv/CMakeLists.txt
rename to src/dist/replication/storage_engine/simple_kv/CMakeLists.txt
index 802402d5ad..d25d454f9c 100644
--- a/src/apps/skv/CMakeLists.txt
+++ b/src/dist/replication/storage_engine/simple_kv/CMakeLists.txt
@@ -22,7 +22,6 @@ file(GLOB
     RES_FILES
     "${CMAKE_CURRENT_SOURCE_DIR}/*.ini"
     "${CMAKE_CURRENT_SOURCE_DIR}/*.sh"
-    "${CMAKE_CURRENT_SOURCE_DIR}/*.cmd"
     )
 
 # Extra files that will be installed
diff --git a/src/apps/skv/clear.sh b/src/dist/replication/storage_engine/simple_kv/clear.sh
similarity index 100%
rename from src/apps/skv/clear.sh
rename to src/dist/replication/storage_engine/simple_kv/clear.sh
diff --git a/src/apps/skv/config.ini b/src/dist/replication/storage_engine/simple_kv/config.ini
similarity index 100%
rename from src/apps/skv/config.ini
rename to src/dist/replication/storage_engine/simple_kv/config.ini
diff --git a/src/apps/skv/run.sh b/src/dist/replication/storage_engine/simple_kv/run.sh
similarity index 100%
rename from src/apps/skv/run.sh
rename to src/dist/replication/storage_engine/simple_kv/run.sh
diff --git a/src/apps/skv/simple_kv.app.example.h b/src/dist/replication/storage_engine/simple_kv/simple_kv.app.example.h
similarity index 96%
rename from src/apps/skv/simple_kv.app.example.h
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.app.example.h
index dfb0379c90..969521ebe0 100644
--- a/src/apps/skv/simple_kv.app.example.h
+++ b/src/dist/replication/storage_engine/simple_kv/simple_kv.app.example.h
@@ -34,7 +34,7 @@
  */
 
 #pragma once
-#include "simple_kv.client.2.h"
+#include "simple_kv.client.h"
 #include "simple_kv.server.h"
 
 #define TRANSPARENT_LAYER2_CLIENT
@@ -57,7 +57,7 @@ class simple_kv_client_app : public ::dsn::service_app
 
         // argv[1]: e.g., dsn://mycluster/simple-kv.instance0
         _server.assign_uri(args[1].c_str());
-        _simple_kv_client.reset(new simple_kv_client2(_server));
+        _simple_kv_client.reset(new simple_kv_client(_server));
 
         _timer = ::dsn::tasking::enqueue_timer(LPC_SIMPLE_KV_TEST_TIMER,
                                                &_tracker,
@@ -123,7 +123,7 @@ class simple_kv_client_app : public ::dsn::service_app
 private:
     ::dsn::task_ptr _timer;
     ::dsn::rpc_address _server;
-    std::unique_ptr<simple_kv_client2> _simple_kv_client;
+    std::unique_ptr<simple_kv_client> _simple_kv_client;
     dsn::task_tracker _tracker;
 };
 }
diff --git a/src/apps/skv/simple_kv.client.2.h b/src/dist/replication/storage_engine/simple_kv/simple_kv.client.h
similarity index 97%
rename from src/apps/skv/simple_kv.client.2.h
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.client.h
index 2c90b9a95f..41e57ac14c 100644
--- a/src/apps/skv/simple_kv.client.2.h
+++ b/src/dist/replication/storage_engine/simple_kv/simple_kv.client.h
@@ -8,14 +8,14 @@
 namespace dsn {
 namespace replication {
 namespace application {
-class simple_kv_client2
+class simple_kv_client
 {
 public:
-    simple_kv_client2(::dsn::rpc_address server) { _server = server; }
+    simple_kv_client(::dsn::rpc_address server) { _server = server; }
 
-    simple_kv_client2() {}
+    simple_kv_client() {}
 
-    virtual ~simple_kv_client2() {}
+    virtual ~simple_kv_client() {}
 
     // ---------- call RPC_SIMPLE_KV_SIMPLE_KV_READ ------------
     // - synchronous
diff --git a/src/apps/skv/simple_kv.code.definition.h b/src/dist/replication/storage_engine/simple_kv/simple_kv.code.definition.h
similarity index 100%
rename from src/apps/skv/simple_kv.code.definition.h
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.code.definition.h
diff --git a/src/apps/skv/simple_kv.main.cpp b/src/dist/replication/storage_engine/simple_kv/simple_kv.main.cpp
similarity index 100%
rename from src/apps/skv/simple_kv.main.cpp
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.main.cpp
diff --git a/src/apps/skv/simple_kv.server.h b/src/dist/replication/storage_engine/simple_kv/simple_kv.server.h
similarity index 100%
rename from src/apps/skv/simple_kv.server.h
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.server.h
diff --git a/src/apps/skv/simple_kv.server.impl.cpp b/src/dist/replication/storage_engine/simple_kv/simple_kv.server.impl.cpp
similarity index 100%
rename from src/apps/skv/simple_kv.server.impl.cpp
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.server.impl.cpp
diff --git a/src/apps/skv/simple_kv.server.impl.h b/src/dist/replication/storage_engine/simple_kv/simple_kv.server.impl.h
similarity index 100%
rename from src/apps/skv/simple_kv.server.impl.h
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.server.impl.h
diff --git a/src/apps/skv/simple_kv.thrift b/src/dist/replication/storage_engine/simple_kv/simple_kv.thrift
similarity index 100%
rename from src/apps/skv/simple_kv.thrift
rename to src/dist/replication/storage_engine/simple_kv/simple_kv.thrift
diff --git a/src/apps/skv/simple_kv_types.cpp b/src/dist/replication/storage_engine/simple_kv/simple_kv_types.cpp
similarity index 100%
rename from src/apps/skv/simple_kv_types.cpp
rename to src/dist/replication/storage_engine/simple_kv/simple_kv_types.cpp
diff --git a/src/apps/skv/simple_kv_types.h b/src/dist/replication/storage_engine/simple_kv/simple_kv_types.h
similarity index 100%
rename from src/apps/skv/simple_kv_types.h
rename to src/dist/replication/storage_engine/simple_kv/simple_kv_types.h