diff --git a/include/server/dnode.h b/include/server/dnode.h
deleted file mode 100644
index 0fe5a66238c13ae755280d719a415c3ac1aca8ab..0000000000000000000000000000000000000000
--- a/include/server/dnode.h
+++ /dev/null
@@ -1,27 +0,0 @@
-/*
- * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
- *
- * This program is free software: you can use, redistribute, and/or modify
- * it under the terms of the GNU Affero General Public License, version 3
- * or later ("AGPL"), as published by the Free Software Foundation.
- *
- * This program is distributed in the hope that it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
-
-#ifndef _TD_DNODE_H_
-#define _TD_DNODE_H_
-
-#ifdef __cplusplus
-extern "C" {
-#endif
-
-#ifdef __cplusplus
-}
-#endif
-
-#endif /*_TD_DNODE_H_*/
\ No newline at end of file
diff --git a/include/server/dnode/dnode.h b/include/server/dnode/dnode.h
new file mode 100644
index 0000000000000000000000000000000000000000..fae60495e9a230a46567c5b7ff32a3152c6bb323
--- /dev/null
+++ b/include/server/dnode/dnode.h
@@ -0,0 +1,75 @@
+/*
+ * Copyright (c) 2019 TAOS Data, Inc. <jhtao@taosdata.com>
+ *
+ * This program is free software: you can use, redistribute, and/or modify
+ * it under the terms of the GNU Affero General Public License, version 3
+ * or later ("AGPL"), as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef _TD_DNODE_H_
+#define _TD_DNODE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct SRpcMsg;
+struct SRpcEpSet;
+
+/**
+ * Initialize and start the dnode module
+ * 
+ * @return Error Code
+ */
+int32_t dnodeInit();
+
+/**
+ * Stop and cleanup dnode module
+ */
+void dnodeCleanup();
+
+/**
+ * Send messages to other dnodes, such as create vnode message.
+ *
+ * @param epSet The endpoint list of the dnodes.
+ * @param rpcMsg Message to be sent.
+ */
+void dnodeSendMsgToDnode(SRpcEpSet *epSet, SRpcMsg *rpcMsg);
+
+/**
+ * Send messages to mnode, such as config message.
+ *
+ * @param rpcMsg Message to be sent.
+ */
+void dnodeSendMsgToMnode(SRpcMsg *rpcMsg);
+
+/**
+ * Get the corresponding endpoint information from dnodeId.
+ *
+ * @param dnodeId
+ * @param ep The endpoint of dnode
+ * @param fqdn The fqdn of dnode
+ * @param port The port of dnode
+ */
+void dnodeGetDnodeEp(int32_t dnodeId, char *ep, char *fqdn, uint16_t *port);
+
+/**
+ * Report to dnode the start-up steps of other modules
+ *
+ * @param name Name of the start-up phase.
+ * @param desc Description of the start-up phase.
+ */
+void dnodeReportStartup(char *name, char *desc);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*_TD_DNODE_H_*/
\ No newline at end of file
diff --git a/include/server/mnode/mnode.h b/include/server/mnode/mnode.h
index d458d3a91fbc231be394e570668f2d849f401e30..0d2fd00ba1e85daf9c10c19c5b464e3b08bc0605 100644
--- a/include/server/mnode/mnode.h
+++ b/include/server/mnode/mnode.h
@@ -20,6 +20,47 @@
 extern "C" {
 #endif
 
+struct SRpcMsg;
+
+/**
+ * Deploy Mnode instances in Dnode.
+ * 
+ * @return Error Code.
+ */
+int32_t mnodeDeploy();
+
+/**
+ * Delete the Mnode instance deployed in Dnode.
+ */
+void mnodeUnDeploy();
+
+/**
+ * Start Mnode service.
+ * 
+ * @return Error Code.
+ */
+int32_t mnodeStart();
+
+/**
+ * Stop Mnode service.
+ */
+int32_t mnodeStop();
+
+/**
+ * Interface for processing messages.
+ * 
+ * @param pMsg Message to be processed.
+ * @return Error code
+ */
+int32_t mnodeProcessMsg(SRpcMsg *pMsg);
+
+/**
+ * Whether the Mnode is in service.
+ * 
+ * @return Server status.
+ */
+bool mnodeIsServing();
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/include/server/vnode/vnode.h b/include/server/vnode/vnode.h
index 6dea4a4e57392be988126c579648f39a8270b9bf..4a848add59ed5f68d292472531f0897a05f169cf 100644
--- a/include/server/vnode/vnode.h
+++ b/include/server/vnode/vnode.h
@@ -11,4 +11,52 @@
  *
  * You should have received a copy of the GNU Affero General Public License
  * along with this program. If not, see <http://www.gnu.org/licenses/>.
- */
\ No newline at end of file
+ */
+
+#ifndef _TD_VNODE_H_
+#define _TD_VNODE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+struct SRpcMsg;
+
+/**
+ * Start Initialize Vnode module.
+ *
+ * @return Error Code.
+ */
+int32_t vnodeInit();
+ 
+/**
+ * Cleanup Vnode module.
+ */
+void vnodeCleanup();
+ 
+typedef struct {
+  int64_t queryMsgCount;
+  int64_t writeMsgCount;
+} SVnodeStat;
+ 
+/**
+ * Get the statistical information of Vnode
+ *
+ * @param stat Statistical information.
+ * @return Error Code.
+ */
+int32_t vnodeGetStatistics(SVnodeStat *stat);
+
+/** 
+ * Interface for processing messages.
+ *
+ * @param pMsg Message to be processed.
+ * @return Error code
+ */
+int32_t vnodeProcessMsg(SRpcMsg *pMsg);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /*_TD_VNODE_H_*/
\ No newline at end of file
diff --git a/source/server/CMakeLists.txt b/source/server/CMakeLists.txt
index ab88d501910345135505097c87ef441bf3c74913..36273abe92db16557292cca5b543c19e1272c575 100644
--- a/source/server/CMakeLists.txt
+++ b/source/server/CMakeLists.txt
@@ -2,7 +2,7 @@ add_subdirectory(mnode)
 add_subdirectory(vnode)
 add_subdirectory(qnode)
 
-aux_source_directory(dnode TAOSD_SRC)
+aux_source_directory(taosd TAOSD_SRC)
 add_executable(taosd ${TAOSD_SRC})
 target_link_libraries(
     taosd
diff --git a/source/server/dnode/main.c b/source/server/taosd/main.c
similarity index 100%
rename from source/server/dnode/main.c
rename to source/server/taosd/main.c