Adds failover to database connection #179

KhalisFoundation · Jun 22, 2020 · c6d05c9 · c6d05c9
1 parent c50a0e4
commit c6d05c9
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Showing 2 changed files with 16 additions and 31 deletions.
diff --git a/api/config/index.js b/api/config/index.js
@@ -3,28 +3,33 @@ const metadata = {
   password: process.env.DB_PASSWORD || 'root',
   database: process.env.NODE_ENV === 'development' ? 'khajana_dev_khajana' : 'khajana_khajana',
   dateStrings: true,
+  acquireTimeout: 5000,
   connectionLimit: process.env.DB_POOL_SIZE,
 };
+const standbyMetadata = {
+  port: 3306,
+  minimumIdle: 0,
+};
 
 module.exports = {
   mysql0: {
     host: 'localhost',
     port: process.env.DB_PORT || 3306,
     ...metadata,
   },
-  mysql2: {
+  mysql1: {
     host: 'db1.khalis.net',
-    port: 3306,
     ...metadata,
+    ...standbyMetadata,
   },
   mysql2: {
     host: 'db2.khalis.net',
-    port: 3306,
     ...metadata,
+    ...standbyMetadata,
   },
-  mysql2: {
+  mysql3: {
     host: 'db3.khalis.net',
-    port: 3306,
     ...metadata,
+    ...standbyMetadata,
   },
 };
diff --git a/app.js b/app.js
@@ -2,39 +2,19 @@ const express = require('express');
 const bodyParser = require('body-parser');
 const cors = require('cors');
 const cacheControl = require('express-cache-controller');
-const { createPool } = require('mariadb');
+const { createPoolCluster } = require('mariadb');
 const config = require('./api/config');
 const routes = require('./api/routes');
 
 const app = express();
 const port = process.env.NODE_ENV === 'development' ? '3001' : '3000';
 
 //database
-try {
-  app.locals.pool = createPool(config.mysql0);
-  app.local.pool.getConnection().query('SELECT 1');
-} catch (err) {
-  try {
-    app.locals.pool = createPool(config.mysql1);
-    app.local.pool.getConnection().query('SELECT 1');
-    console.log('Failed to DB1');
-  } catch (err) {
-    try {
-      app.locals.pool = createPool(config.mysql2);
-      app.local.pool.getConnection().query('SELECT 1');
-      console.log('Failed to DB2');
-    } catch (err) {
-      try {
-        app.locals.pool = createPool(config.mysql3);
-        app.local.pool.getConnection().query('SELECT 1');
-        console.log('Failed to DB3');
-      } catch (err) {
-        console.log('Could not connect to any database!');
-        console.log(err);
-      }
-    }
-  }
-}
+app.locals.pool = createPoolCluster();
+app.locals.pool.add('local', config.mysql0);
+app.locals.pool.add('db1', config.mysql1);
+app.locals.pool.add('db2', config.mysql2);
+app.locals.pool.add('db3', config.mysql3);
 
 // app
 app.use(cors());