diff --git a/db/access_tokens.js b/db/access_tokens.js
index 23321f2..dacc2c4 100644
--- a/db/access_tokens.js
+++ b/db/access_tokens.js
@@ -1,5 +1,6 @@
 'use strict';
 
+const {logger, authl} = global;
 const loki = require('lokijs');
 
 global.dbl = new loki('./loki.json', {
@@ -7,46 +8,50 @@ global.dbl = new loki('./loki.json', {
     autosave: true,
     autosaveInterval: 5000,
     autoloadCallback() {
-        global.authl = global.dbl.getCollection('tokens');
-        if (global.authl === null) {
-            global.authl = global.dbl.addCollection('tokens');
+        authl = global.dbl.getCollection('tokens');
+        if (authl === null) {
+            authl = global.dbl.addCollection('tokens');
         }
     }
 });
 
 module.exports.find = (key, done) => {
-    const ltoken = global.authl.findOne({'token': key});
+    const ltoken = authl.findOne({'token': key});
     if (ltoken){
         const {userId, clientId} = ltoken;
         return done(null, {userId, clientId})
     } else {
-        global.logger.log('error', new Error('Token Not Found'));
+        logger.log('error', new Error('Token Not Found'));
         return done();
     }  
 };
 
 module.exports.findByUserIdAndClientId = (userId, clientId, done) => {
-    const ltoken = global.authl.findOne({'userId': userId});
+    const ltoken = authl.findOne({'userId': userId});
     if (ltoken){
-        global.logger.log('info', {message: `Load token by userId (${userId}): User found`});
+        logger.log('info', {message: `Load token by userId (${userId}): User found`});
         const {token, userId: uid, clientId: cid} = ltoken;
-        if (uid === userId && cid === clientId) return done(null, token);
-        else return done(new Error('Token Not Found'));
+        if (uid === userId && cid === clientId) {
+            return done(null, token);
+        } else {
+            logger.log('error', new Error('Token Not Found'));
+            return done();
+        }
     } else {
-        console.log('User not found');
-        return done(new Error('User Not Found'));
+        logger.log('error', new Error('User Not Found'));
+        return done();
     }  
 };
 
 module.exports.save = (token, userId, clientId, done) => {
-    global.logger.log('info', {message: `Start saving token`});
-    const ltoken = global.authl.findOne({'userId': userId});
+    logger.log('info', {message: `Start saving token`});
+    const ltoken = authl.findOne({'userId': userId});
     if (ltoken){
-        global.logger.log('info', {message: `User Updated`});
-        global.authl.update(Object.assign({}, ltoken, {token, userId, clientId}));
+        logger.log('info', {message: `User Updated`});
+        authl.update(Object.assign({}, ltoken, {token, userId, clientId}));
     } else {
-        global.logger.log('info', {message: `User not Found. Create new...`});
-        global.authl.insert({'type': 'token', token, userId, clientId});
+        logger.log('info', {message: `User not Found. Create new...`});
+        authl.insert({'type': 'token', token, userId, clientId});
     }
     done();
 };
diff --git a/db/authorization_codes.js b/db/authorization_codes.js
index ae37649..c716cf2 100644
--- a/db/authorization_codes.js
+++ b/db/authorization_codes.js
@@ -1,10 +1,15 @@
 'use strict';
 
+const {logger} = global;
 const codes = {};
 
 module.exports.find = (key, done) => {
-    if (codes[key]) return done(null, codes[key]);
-    return done(new Error('Code Not Found'));
+    if (codes[key]) {
+        return done(null, codes[key]);
+    } else {
+        logger.log('error', new Error('Code Not Found'));
+        return done();
+    }
 };
 
 module.exports.save = (code, clientId, redirectUri, userId, userName, done) => {
diff --git a/db/clients.js b/db/clients.js
index e49069f..4308a4b 100644
--- a/db/clients.js
+++ b/db/clients.js
@@ -1,17 +1,20 @@
 'use strict';
 
+const {logger} = global;
 const {clients} = require('../config'); 
 
 module.exports.findById = (id, done) => {
     for (const client of clients) {
         if (client.id === id) return done(null, client);
     }
-    return done(new Error('Client Not Found'));
+    logger.log('error', new Error('Client Not Found'));
+    return done();
 };
 
 module.exports.findByClientId = (clientId, done) => {
     for (const client of clients) {
         if (client.clientId === clientId) return done(null, client);
     }
-    return done(new Error('Client Not Found'));
+    logger.log('error', new Error('Client Not Found'));
+    return done();
 };
diff --git a/db/users.js b/db/users.js
index 906954d..e2bf6a6 100644
--- a/db/users.js
+++ b/db/users.js
@@ -1,17 +1,20 @@
 'use strict';
 
+const {logger} = global;
 const {users} = require('../config');
 
 module.exports.findById = (id, done) => {
     for (const user of users) {
         if (user.id === id) return done(null, user);
     }
-    return done(new Error('User Not Found'));
+    logger.log('error', new Error('User Not Found'));
+    return done();
 };
 
 module.exports.findByUsername = (username, done) => {
     for (const user of users) {
         if (user.username === username) return done(null, user);
     }
-    return done(new Error('User Not Found'));
+    logger.log('error', new Error('User Not Found'));
+    return done();
 };
diff --git a/device.js b/device.js
index 5b0168f..0f3c069 100644
--- a/device.js
+++ b/device.js
@@ -1,3 +1,5 @@
+const {logger} = global;
+
 /* function for convert system values to Yandex (depends of capability or property type) */
 function convertToYandexValue(val, actType) {
     switch(actType) {
@@ -8,7 +10,7 @@ function convertToYandexValue(val, actType) {
                 const value = parseFloat(val);
                 return isNaN(value) ? 0.0 : value;
             } catch(e) {
-                console.error(`Can't parse to float: ${val}`);
+                logger.log('error', {message: `Can't parse to float: ${val}`});
                 return 0.0;
             }
         }
@@ -96,7 +98,7 @@ class Device {
                 }
             }
             default: {
-                console.error(`Unsupported capability type: ${type}`)
+                logger.log('error', {message: `Unsupported capability type: ${type}`});
                 return undefined;
             }
         }
@@ -195,7 +197,7 @@ class Device {
             message = `${value}`;
         } catch(e) {              
             topic = false;
-            global.logger.log('error', {message: `${e}`});
+            logger.log('error', {message: `${e}`});
         }
 
         if (topic) {
@@ -225,7 +227,7 @@ class Device {
             const value = this.getMappedValue(val, actType, false);
             cp.state = {instance, value: convertToYandexValue(value, actType)};
         } catch(e) {
-            global.logger.log('error', {message: `${e}`});
+            logger.log('error', {message: `${e}`});
         }
     }
 }