standalone version of poolTimeout.js

pool-timeout.js

var oracledb = require('oracledb');
var async    = require('async');
var dbConfig = require('./dbconfig.js');

async.waterfall(
  [
    function(callback) 
    {
      var credential = 
        {
          user          : dbConfig.user,
          password      : dbConfig.password,
          connectString : dbConfig.connectString,
          poolMin       : 1,
          poolMax       : 5,
          poolIncrement : 2,
          stmtCacheSize : 23
        };

      oracledb.createPool(credential, callback);
    },
    function(pool, callback) 
    {
      pool.getConnection( function(err, conn1) {
        if (err) 
          return callback(err);  
        else 
        {
          console.log("-- 1st connection created."); 
          return callback(null, conn1, pool);
        }
      });
    },
    function(conn1, pool, callback) {
      pool.getConnection( function(err, conn2) {
        if (err) 
          return callback(err);  
        else 
        {
          console.log("-- 2nd connection created."); 
          return callback(null, conn1, conn2, pool);
        }
      });
    },
    function(conn1, conn2, pool, callback) {
      pool.getConnection( function(err, conn3) {
        if (err) 
          return callback(err);  
        else 
        {
          console.log("-- 3rd connection created."); 
          return callback(null, conn1, conn2, conn3, pool);
        }
      });
    },
    function(conn1, conn2, conn3, pool, callback) {
      conn1.release(function(err) {
        if (err)
          return callback(err);
        else 
        {
          console.log("-- 1st connection released.");
          return callback(null, conn2, conn3, pool);
        }
      });
    }, 
    function(conn2, conn3, pool, callback) {
      conn2.release(function(err) {
        if (err) 
          return callback(err);
        else
        {
          console.log("-- 2nd connection released.");
          return callback(null, conn3, pool);
        }
      });
    },
    function(conn3, pool, callback) {
      conn3.release(function(err) {
        if (err)
          return callback(err);
        else
        {
          console.log("-- 3rd connection released.");
          return callback(null, pool);
        }
      });
    },
    function(pool, callback) {
      setTimeout(function() {
        return callback(null, pool);
      }, 7000);
    },
    function(pool, callback) {
      pool.getConnection( function(err, conn4) {
        if (err) 
          return callback(err);  
        else 
        {
          console.log("-- 4th connection created."); 
          return callback(null, conn4, pool);
        }
      });
    }, 
    function(conn4, pool, callback) {
      conn4.release(function(err) {
        if (err)
          return callback(err);
        else
        {
          console.log("-- 4th connection released.");
          return callback(null, pool);
        }
      });
    },
    function(pool, callback) {
      pool.terminate( callback );
    }
  ],
  function(err) 
  {
    if (err) { 
      console.error("In waterfall error cb: ==>", err, "<=="); 
    } else {
      console.log("DONE!");
    } 
  }
);

This is the output on my machine:
-- 1st connection created.
-- 2nd connection created.
-- 3rd connection created.
-- 1st connection released.
-- 2nd connection released.
-- 3rd connection released.
-- 4th connection created.
-- 4th connection released.
DONE!