I need to be able to run my Heroku app 24/7 even when no one is currently viewing it. It's primarily a server side application that I need to constantly be running at all times.
What's the cheapest and best way to go about doing this. I don't mind paying as long as I'm not paying unnecessarily.
Thank you.
You have three options:
Hobby subscription
Free Web Dyno
Free Worker Dyno
(1) Go for the Hobby subscription: 7$ per month, the Dyno is 24/7 up and running
(2) Use the Free tier, register a valid credit card which gives you extra free Dyno hours (total of 1000 hours) and make sure the Dyno is always up.
The Free Web Dyno sleeps after 30 min inactivity (ie no incoming requests for 30 minutes): you can prevent this sending a request (from an external tool or script) every 20 min.
(3) Use the Free tier (again register a valid credit card to be eligible to 1000 free hours) with a Worker Dyno only (free worker dyno do not sleep)
More info at Free Dyno Sleeping
Related
According to heroku
Starting today, Heroku accounts have an account-based pool of free dyno hours for use on free apps. This replaces the 18 hours a day limit on free apps, allowing a free app to run 24/7 if needed. New accounts receive 550 free dyno hours and you can verify your identity with a credit card for an additional 450 hours
→ How are dyno hours calculated
If my app is always up, how many days will it stay up for (If I have 550 dyno hours) or does it depend on traffic and usage?
An app consumes hours based on their uptime, no matter the usage or traffic your app receives.
If you do the math, 550 hours is equal to 22.92 days.
If you were to add your payment method, it would give you a thousand hours, enough for a single app to run 24/7.
If I only have one active app is it possible that it could spend all free Dyno hours quota?
My app is a PHP process which is always active (while (true) { do_something}). I launch this process as a worker.
I thought the free Dyno hours quota were like real hours so you can spent 24h as max per day. But if I view my remaining free hours quota in two consecutive days using 'heroku ps -a app' command then I get that I am spending more than 24h per day.
Another question, how many hours do you have in a Hobby plan?
If you are running 2 dynos (for example, a web dyno and a worker dyno), they will each use 24 hours, for a total of 48 dyno hours used in a day. Of course in reality it would probably be less than 24 hours each, if the dynos slept for part of the day.
I solved my problem disabling the web Dyno.
Is it possible to stop a Heroku Daily Dyno Restart for a Hobby Dyno?
My Goal is to stop the Dyno from restarting.
In short, No (with an aside that the restart shouldn't be seen as a bad thing).
From the Heroku Dynos and Dyno Manager Docs
Dynos are also restarted (cycled) at least once per day to help maintain the health of applications running on Heroku. Any changes to the local filesystem will be deleted. The cycling happens once every 24 hours (plus up to 216 random minutes, to prevent every dyno for an application from restarting at the same time).
Cycling happens for all dynos, including one-off dynos, so dynos will run for a maximum of 24 hours + 216 minutes.
In addition, dynos are restarted as needed for the overall health of the system and your app. For example, the dyno manager occasionally detects a fault in the underlying hardware and needs to move your dyno to a new physical location.
Additionally, Dynos Restart if you:
create a new release by deploying new code
change your config vars
change your add-ons
run heroku restart
With Hobby Dynos, the real issue is that inactivity causes the Dyno to sleep throughout the day. From my personal experience, waking up a sleeping dyno can cause a page to take ~30s to load.
There are many solutions to 'ping' the dyno on regular intervals to keep it 'awake'.
An example solution for a Node Server is heroku-self-ping
Is heroku's free 750 hours separate per app, or is it a total of 750 hours shared across all your apps?
From their site:
"Each app you create has free access to 750 dyno-hours per month and a starter-tier database."
However, from another answer on StackOverflow:
"Heroku provides, for free, 1 dyno. A dyno is an instance of your application running and responding to requests. If each instance of your application can serve each request in 100ms, then you get 600 requests/minute with the free account."
Based off of what it says there and my experience it's per app. That's talking about instances of dynos not apps. "If each instance of your application can serve each request in 100ms, then you get 600 requests/minute with the free account."
Each app you create within Heroku gets 750 dyno-hours per month for free. The number of requests your app can receive depend on the configuration of the app. For example, an app running unicorn can handle more requests than an app running something else, as unicorn can run multiple workers per dyno.
I've personally run an app on Heroku with 3 unicorn workers on one dyno, 24 hours a day, all month, and always been free (because that is ~750 dyno-hours).
'1. I currently have 1 worker dyno doing background work. I does so every day for about an hour. The rest of the time the worker dyno recognizes, that it has nothing to do and terminates. The dyno manager will respawn the dyno and after a few seconds the dyno will terminate.
It is not clear to me how this will count in computing hours, esepecially as
https://dashboard.heroku.com/account
Shows "Not available" in the current usage statistics.
The Scheduler addon doesn't seem to be the right tool for me, as they are meant for to schedule short running background tasks (according to the description)
Q1: How does a crashed worker process consume dyno hours?
'2. How is my web app being charged when idle? The documentation says "A web dyno that is idled continues to accrue usage. To stop accruing usage, you must scale the web dyno to 0". This means that an idle web app is using the same dyno hours or at a reduced rate? "continues to accrue usage" would suggest some lower rate but isn't clear out of context.
Q2: To what rate does an idling web worker consume dyno hours?
For my understanding: Heroku does not differentiate between the Dyno types when it comes to pricing. An idled Dyno will produce the same cost like a running Dyno. But Heroku says on their website: "... Workers dynos are never idled out."
A crashed Dyno will constantly try to restart with a 10 minute break (after restart fails twice in a row).