How to use expire_time parameter with the Node.js node-oracledb? - oracle19c

Question

Sample Code
try {
const oracledb = require('oracledb');
const express = require('express');
const app = express();
// Memorized Connections
var allDBSessions = {};
app.get('/', (req, res) => {
const dbConfig = {
user: 'vph_dev_ad_gss_tran',
password: 'Gsstpl100'
// ,connectString: '//IP:PORT/SERVICE_NAME' // Working as Expected
,connectString: '//IP:PORT/SERVICE_NAME?expire_time=1' // Minutes // Not Working
// ,connectString: '//IP:PORT/SERVICE_NAME?connect_timeout=15' // Seconds // Not Working
// Your connection string could be "mydbmachine.example.com/orclpdb1?expire_time=2" // Sample From Node Oracledb Site
};
async function ExecuteQuery() {
try {
// Getting DB Connections
let dbInstance;
if (allDBSessions.first_instance) {
// Assigning From Memorized Connections
console.log('Connection Available From the Memory');
console.log('Connection Created Time - ' + allDBSessions.first_instance.created_time);
dbInstance = allDBSessions.first_instance.db_connection;
console.log('Connection Assigned From Memory');
} else {
//Creating New DB Instance
console.log('Creating New Connection');
dbInstance = await oracledb.getConnection(dbConfig);
console.log('Connection Created Successfully');
// Memorizing the DB Instance
allDBSessions.first_instance = {
db_connection: dbInstance,
created_time: new Date().toLocaleString()
}
console.log('Connection Stored into Memory');
}
// Executing Query
var query = 'select 1 from dual';
console.log('Executing the Query - ' + query);
let queryResult = await dbInstance.execute(query);
console.log('queryResult', queryResult);
var finalResult = {
'Query Result': queryResult,
'Usedd DB Session Info': allDBSessions.first_instance
};
res.send(finalResult); // Sending Response
} catch (error) {
console.log(error, '----- Catch Error in ExecuteQuery()-----');
res.send(error);
}
}
ExecuteQuery();
})
app.listen(3005, () => {
console.log(`Oracle DB Sample With Expire Timeout`);
console.log(`server is listening on PORT 3005`);
})
} catch (error) {
console.log(error, '----- Catch Error -----');
}
Above Sample Throwing Error while trying to make a successful Connection with the Oracle Db which is 19c.
Error Shown below
[Error: ORA-12514: TNS:listener does not currently know of service requested in connect descriptor] {
errorNum: 12514,
offset: 0
}
Please guide me to overcome from this issue...
Thanks In AdvancE...
HaPPy CodinG...

Answer 1

The Easy Connect Plus syntax like '//IP:PORT/SERVICE_NAME?expire_time=1' is usable when the Oracle Client libraries that node-oracledb uses are 19c or later. The database version doesn't matter. See the architecture diagram in the documentation.
Check what client libraries node-oracledb is using by running the example app version.js. It will output something like:
$ node version.js
Run at: Thu Mar 18 2021 08:17:22 GMT+1100 (Australian Eastern Daylight Time)
Node.js version: v12.21.0 (darwin x64)
Node-oracledb version: 5.2.0-dev
Oracle Client library version: 19.8.0.0.0
Oracle Database version: 19.3.0.0.0
Check your Oracle Client library version is 19 or later.
Update on EXPIRE_TIME:
With 18c client libraries it can be added as (EXPIRE_TIME=n) to the DESCRIPTION section of a connect descriptor (in a full connect descriptor string in the app, or in the tnsnames.ora file).
With 19c client libraries it can be used via Easy Connect: host/service?expire_time=n.
With 21c client libraries it can be used in a client-side (i.e. Node.js machine) sqlnet.ora.