131 lines
4.2 KiB
JavaScript
131 lines
4.2 KiB
JavaScript
/* Copyright (c) 2018, 2019, Oracle and/or its affiliates. All rights reserved. */
|
|
|
|
/******************************************************************************
|
|
*
|
|
* You may not use the identified files except in compliance with the Apache
|
|
* License, Version 2.0 (the "License.")
|
|
*
|
|
* You may obtain a copy of the License at
|
|
* http://www.apache.org/licenses/LICENSE-2.0.
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
|
|
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
*
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*
|
|
* NAME
|
|
* sessionfixup.js
|
|
*
|
|
* DESCRIPTION
|
|
* Shows using a pooled connection callback function to efficiently
|
|
* set the "session state" of pooled connections to the same values
|
|
* when each connection is first used.
|
|
*
|
|
* Each connection in a connection pool can retain state (such as
|
|
* ALTER SESSION values) from when the connection was previously
|
|
* used. Using a sessionCallback function for a connection pool
|
|
* removes the overhead of unnecessarily re-executing ALTER SESSION
|
|
* commands after each pool.getConnection() call.
|
|
*
|
|
* Run this script and experiment sending web requests. For example
|
|
* send 20 requests with a concurrency of 4:
|
|
* ab -n 20 -c 4 http://127.0.0.1:7000/
|
|
* The function initSession() will be called just once per connection
|
|
* in the pool.
|
|
*
|
|
* This file uses Node 8's async/await syntax but could be rewritten
|
|
* to use callbacks.
|
|
*
|
|
* This example requires node-oracledb 3.1 or later.
|
|
*
|
|
* Also see sessiontagging1.js and sessiontagging2.js
|
|
*
|
|
*****************************************************************************/
|
|
|
|
const http = require('http');
|
|
const oracledb = require('oracledb');
|
|
const dbConfig = require('./dbconfig.js');
|
|
const httpPort = 7000;
|
|
|
|
// initSession() will be invoked internally when each brand new pooled
|
|
// connection is first used. Its callback function 'cb' should be
|
|
// invoked only when all desired session state has been set.
|
|
// In this example, the requestedTag and actualTag parameters are
|
|
// ignored. They would be valid if connection tagging was being used.
|
|
// If you have multiple SQL statements to execute, put them in a
|
|
// single, anonymous PL/SQL block for efficiency.
|
|
function initSession(connection, requestedTag, cb) {
|
|
console.log('In initSession');
|
|
connection.execute(`ALTER SESSION SET TIME_ZONE = 'UTC'`, cb);
|
|
}
|
|
|
|
async function init() {
|
|
try {
|
|
await oracledb.createPool({
|
|
user: dbConfig.user,
|
|
password: dbConfig.password,
|
|
connectString: dbConfig.connectString,
|
|
sessionCallback: initSession,
|
|
poolMin: 1,
|
|
poolMax: 4,
|
|
poolIncrement: 1
|
|
});
|
|
|
|
// Create HTTP server and listen on port httpPort
|
|
const server = http.createServer();
|
|
server.listen(httpPort)
|
|
.on('request', handleRequest)
|
|
.on('error', (err) => {
|
|
console.error('HTTP server problem: ' + err);
|
|
})
|
|
.on('listening', () => {
|
|
console.log('Server running at http://localhost:' + httpPort);
|
|
});
|
|
} catch (err) {
|
|
console.error("init() error: " + err.message);
|
|
}
|
|
}
|
|
|
|
async function handleRequest(request, response) {
|
|
let connection;
|
|
try {
|
|
// Get a connection from the default connection pool
|
|
connection = await oracledb.getConnection();
|
|
let result = await connection.execute(`SELECT TO_CHAR(CURRENT_DATE, 'DD-Mon-YYYY HH24:MI') FROM DUAL`);
|
|
console.log(result.rows[0][0]);
|
|
} catch (err) {
|
|
console.error(err.message);
|
|
} finally {
|
|
if (connection) {
|
|
try {
|
|
await connection.close(); // Put the connection back in the pool
|
|
} catch (err) {
|
|
console.error(err);
|
|
}
|
|
}
|
|
response.end();
|
|
}
|
|
}
|
|
|
|
async function closePoolAndExit() {
|
|
console.log("\nTerminating");
|
|
try {
|
|
// Get the 'default' pool from the pool cache and close it (force
|
|
// closed after 3 seconds).
|
|
// If this hangs, you may need DISABLE_OOB=ON in a sqlnet.ora file
|
|
await oracledb.getPool().close(3);
|
|
process.exit(0);
|
|
} catch(err) {
|
|
console.error(err.message);
|
|
process.exit(1);
|
|
}
|
|
}
|
|
|
|
process
|
|
.once('SIGTERM', closePoolAndExit)
|
|
.once('SIGINT', closePoolAndExit);
|
|
|
|
init();
|