I have a schedule nodejs script. Basically, it has schedule and command tables. Schedule table have many command row. The nodejs script checks the schedule table every 5 seconds. If it is the scheduled time matching up current time. I insert the command row (from schedule table) to command table.
The bug is
I run my script on my laptop and testing local copy of the database on my laptop. A single command in schedule table is only inserted once.
I run my script on my laptop and testing RDS (remote mysql server) on my laptop. A single command in schedule table is only inserted twice, but one of them, SchduleId is null. (Why ScheduleId is NULL?)
Full code
var config = require("./config.js");
var Promise = require('bluebird');
var mysql = require('promise-mysql');
var ON_DEATH = require('death');
var g_pool = null;
function connect_db() {
g_pool = mysql.createPool(config.db_config);
}
function close_db() {
g_pool.end(function (err) {
// all connections in the pool have ended
});
}
// http://thecodeship.com/web-development/alternative-to-javascript-evil-setinterval/
function interval(func, wait, times){
var interv = function(w, t) {
return function() {
if(typeof t === "undefined" || t-- > 0) {
setTimeout(interv, w);
try {
func.call(null);
}
catch(e) {
t = 0;
throw e.toString();
}
}
};
}(wait, times);
setTimeout(interv, wait);
}
function get_current_utc_time() {
var curr_date_obj = new Date();
var time_utc = "";
// somehow the date format is not accurate.
//var time_utc = dateFormat(now, "yyyy-mm-dd h:MM:ss", true);
var year = curr_date_obj.getUTCFullYear();
var month = add_zero(curr_date_obj.getUTCMonth() + 1); // count from 0
var date = add_zero(curr_date_obj.getUTCDate()); // count from 1
var hr = add_zero(curr_date_obj.getUTCHours());
var min = add_zero(curr_date_obj.getUTCMinutes());
// we ignore the second
var sec = "00";
time_utc = year + "-" + month + "-" + date + " " + hr + ":" + min + ":" + sec;
console.log("-current utc-");
console.log(time_utc);
return time_utc;
};
// http://www.w3schools.com/jsref/jsref_getutchours.asp
function add_zero(i) {
if (i < 10) {
i = "0" + i;
}
return i;
}
function insert_into_pending_cmd(msg_obj) {
console.log();
console.log("-insert_into_pending_cmd-");
var schedule_id = msg_obj.schedule_id;
var device_name = msg_obj.device_name;
var cmd = msg_obj.cmd;
var is_pending = msg_obj.is_pending;
if(is_pending) {
return Promise.resolve();
}
else {
var curr_time = get_current_utc_time();
var sql = "insert into Command set CommandDate = " + "'" + curr_time + "'" + "," + "RemoteName = " + "'" + device_name + "'" + "," + "CommandJSON = " + "'" + cmd + "'" + "," + "CommandComplete = 0" + "," + "ScheduleId = " + "'" + schedule_id + "'";
return g_pool.query(sql).then(function(){
return Promise.resolve();
});
}
}
function is_schedule_cmd_already_pending(msg_obj) {
console.log();
console.log("-is_schedule_cmd_already_pending-");
var schedule_id = msg_obj.schedule_id;
var device_name = msg_obj.device_name;
var cmd = msg_obj.cmd;
var is_run = msg_obj.is_run;
var local_msg_obj = {};
if(is_run) {
var sql = "select count(*) as num from Command where ScheduleId = " + "'" + schedule_id + "'" + " and CommandComplete = 0 and (UNIX_TIMESTAMP(UTC_TIMESTAMP()) - UNIX_TIMESTAMP(CommandDate)) < 600 and (UNIX_TIMESTAMP(UTC_TIMESTAMP()) - UNIX_TIMESTAMP(CommandDate)) > 0";
return g_pool.query(sql).then(function(rows){
var num = rows[0].num;
if(num == 0) {
local_msg_obj = {
schedule_id: schedule_id,
device_name: device_name,
cmd: cmd,
is_pending: false
};
return Promise.resolve(local_msg_obj);
}
else {
local_msg_obj = {
schedule_id: schedule_id,
device_name: device_name,
cmd: cmd,
is_pending: true
};
return Promise.resolve(local_msg_obj);
}
});
}
else {
local_msg_obj = {
schedule_id: schedule_id,
device_name: device_name,
cmd: cmd,
is_pending: true
};
return Promise.resolve(local_msg_obj);
}
}
function is_matchup_schedule_time(row) {
// get all field
var schedule_id = row.ScheduleId;
var device_name = row.ScheduleRemoteName;
var day_code = row.ScheduleDaycode;
var schedule_time = row.ScheduleTime;
var cmd = row.ScheduleCommandJSON;
// get hour and min
var schedule_time_arr = schedule_time.split(":");
var schedule_hour = schedule_time_arr[0];
var schedule_min = schedule_time_arr[1];
// print
console.log();
console.log();
console.log("- schedule_id, device_name, day_code, schedule_time, schedule_hr, schedule_min, cmd -");
console.log(schedule_id);
console.log(device_name);
console.log(day_code);
console.log(schedule_time);
console.log(schedule_hour);
console.log(schedule_min);
console.log(cmd);
// curr date obj
var curr_date_obj = new Date();
var curr_date_code = add_zero(curr_date_obj.getUTCDay());
// print current
console.log();
console.log("- curr_date_code, curr_h, curr_min - ");
console.log(curr_date_code);
console.log(add_zero(curr_date_obj.getUTCHours()));
console.log(add_zero(curr_date_obj.getUTCMinutes()));
// var
var msg_obj = {};
// Match up day
if(day_code == curr_date_code) {
console.log();
console.log(".. match up day ..");
// Match up hour
var curr_hour = add_zero(curr_date_obj.getUTCHours());
if(schedule_hour == curr_hour) {
console.log();
console.log("~~ match up hour ~~");
// Match up min
var curr_min = add_zero(curr_date_obj.getUTCMinutes());
if(schedule_min == curr_min) {
console.log();
console.log("## match up d-h-m, run ##");
msg_obj = {
schedule_id: schedule_id,
device_name: device_name,
cmd: cmd,
is_run: true
};
return Promise.resolve(msg_obj);
}
}
}
else {
}
//
msg_obj = {
schedule_id: schedule_id,
device_name: device_name,
cmd: cmd,
is_run: false
};
return Promise.resolve(msg_obj);
}
// NOTE -------------
function process_schedule_rows(rows) {
return Promise.mapSeries(rows, function(row) {
return is_matchup_schedule_time(row)
.then(is_schedule_cmd_already_pending)
.then(insert_into_pending_cmd)
.catch(function(e){
throw e;
})
});
}
function do_schedule() {
console.log();
console.log("---- start do_schedule ----");
g_pool.query("select * from Schedule order by ScheduleId asc")
.then(process_schedule_rows)
.catch(function(e){
throw e;
});
}
// main func
function main() {
console.log("db host:");
console.log(config.db_host);
connect_db();
interval(function(){
do_schedule();
}, 5000, undefined);
// Clean up
ON_DEATH(function(signal, err) {
console.log();
console.log("-- script interupted --");
console.log("close db");
// close db
close_db();
process.exit();
});
}
// run main func
main();
update 1
I have updated the code to recursive and the insertion still happen twice.
function do_schedule() {
console.log();
console.log("---- start do_schedule ----");
g_pool.query("select * from Schedule order by ScheduleId asc")
.then(process_schedule_rows)
.delay(2000)
.then(do_schedule)
.catch(function(e){
throw e;
});
}
update 2
Currently, the script is checking whether a command is already inserted into the database, if it is, it moves to the next task. If it isn't, it insert the command into pending table.
The script is checking every 2s, it may be too fast for mysql checking whether there is already command.
Well, I set it to 2 min, the same issue still occur. i.g insert twice.
function do_schedule() {
console.log();
console.log("---- start do_schedule ----");
g_pool.query("select * from Schedule order by ScheduleId asc")
.then(process_schedule_rows)
.delay(120000) <------------
.then(do_schedule)
.catch(function(e){
throw e;
});
}
