Worker Dyno go to sleep with the Web dyno - heroku

I'm using heroku to host my discord bot
My bot is mostly designed to be used with the discord chats, but it have a web dashboard for when in need too. I put the bot on heroku, everything seems to be working well, I know about the 30 minutes sleep time for web dyno, and it was fine, since the web dashboard is only used every so often, not 24/24 like the bot. The issue here is, when the web dyno go offline, it also brought the worker dyno down too, which is not what I wanted. Although the documents say that "Worker Dynos do not sleep, since they don't handle web requests", clearly that my worker dyno is sleeping with the web dyno. I don't want to use pinging services, since my 1000 free hours is not enough for both dynos to stay online. Is there a workaround for this? Thanks

Related

How to keep only the worker alive on Heroku free tier from within the app?

I'm testing an app with a worker and a web dyno on Heroku free tier and I'd like to keep the worker alive to be able to execute background tasks while letting the web dyno idle. By default they both go idle in 30 mins even if I have things queued on the worker.
I understand there're ways to keep the web dyno alive (and with that the worker as well), and there're ways to keep the web alive while scaling down the worker. However I'd need the worker alive and the web in idle.
I tried running a recurring job on the worker which would
Restart the dyno.
Scale the dyno down and then back up.
Both approaches worked (as in they restarted and scaled the dyno correctly) but the worker dyno would still idle after 30 mins (as if it's dependent on the web dyno). Edit: yep, that's pretty much the case as explained here: https://devcenter.heroku.com/articles/free-dyno-hours#dyno-sleeping
I could do this form the outside but it seems I'd have to constantly check for the state since a new restart doesn't seem to give me 30 mins headway. I'd also have to expose the API key which I'd like to avoid.
If I've gotten you right, you're trying to stop the web dyno and leave the worker dyno alive.
You could do that by going to the Resources tab:
And then in the 'web' section:
Press the pencil, toggle it off and press 'Confirm'.
As a workaround I currently remove the web dyno and explicitly enable it when I need it. As explained here:
Worker-only Free dynos do not sleep since they do not respond to web
requests.
My workaround was to just create two apps that deploy automatically from the same repository. Then, all you would need to do is enable the worker dyno for one and the web dyno for the other.

Can i use Free Heroku plan as a Telegram Bot?

I want to use Telegram Bot with enabled webHook,
Can I use Heroku free plan as my Bot's Url to hook up when received text message ?
I'm using Nodejs as language.
Yes, you can and it works fine. But Heroku will try to freeze your app for some time. In fact it can't be active for more than 18 of the last 24 hours.
And if you will prevent it, with ping your app or your bot will continuously receive messages, your app will recharge next 6 hours. It's a limit of the free plan.
I suggest that you use Openshift, it doesn't have such limits in free tier.
I guess another suggestion I can make is for you to use glitch.
I use glitch for all the bots I have made so far, it's free, easy to get started with. It also has the limitation where it sleeps after 5 minutes of your bot not being active.
In a post they say the reason why and how to solve it:
Apps sleeping is a large reason why we can offer the Glitch service
for free, so it’s not something we can turn off. However, we accept
that for some use-cases, like bots with no webhooks support, that’s
not ideal. It’s possible to expose a route in your app that a web cron
service or uptime monitoring service can hit and cause your bot to
wake. Doing that every 5 mins or so should do what you want.
Hope it helps.
I have a couple of telegram bots hosted on Heroku's free plan, with webhooks active.
They work fine but as mentioned in other answers the app is put to sleep after 30 minutes of inactivity: webhooks will reactivate it but when waking up there will be some lag and rarely some malfunctions (I lost a couple of commands).
There is a monthly limit of usage time but unless the bot is heavily used I found that this has not ever been a problem.
All in all I like the service, especially since it is free.

Hubot Heroku route message on startup

I have deployed a Hubot on Heroku to interact with Slack. I am using a free dyno currently. After 30 minutes of inactivity, it goes to sleep. It wakes up when pinged from Slack. However, the first request is lost in the mix. So the user has to type the command a second time. Is there an easy way to make the bot wake up and still handle the first command?
As stated in the documentation :
To get around this, you can use the hubot-heroku-keepalive script, which will keep your free dyno alive for up to 18 hours/day. If you never want Hubot to sleep, you will need to upgrade to Heroku's hobby plan.
I use it so Hubot is at least online from 6 AM to midnight.

Heroku free quota per-app or total?

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).

Will my Heroku app working on 1 web dyno stay active if I pay for 1 worker dyno?

I currently have an app deployed on Heroku which runs on two web dynos so it won't go to sleep if it remains inactive for a certain time.
Now if I scale it down to only one web dyno (free) and instead pay for one worker dyno, will Heroku always keep my app active?
It will still idle - you NEED to have more than a single web dyno
https://devcenter.heroku.com/articles/dyno-idling
You can also use the New Relic add-on to monitor your app and keep it alive. There is a tab in settings to configure availability monitoring.
You can also avoid a single web dyno from idling by using a monitoring service like pingdom.com since it's periodically sending a request to your web dyno.
Try Pingdom. Free plans include one website check. I use this service to keep my app active all the time.
Pingdom tests your websites and other infrastructure components as
often as every minute to make sure it is all up and running.
From Pingdom Homepage
Pingdom does this by "pinging" or rather requesting a resource from your website on a regular interval. This has the side effect of keeping your website "active", cache's primed, etc.. because your website is seeing regular "traffic" (the requests coming from pingdom).
Try Un-idler. You don't need to sign in and it's free.
http://unidler.herokuapp.com/
You can try http://kaffeine.herokuapp.com/ it will ping your app every 30 minutes so your app won't go to sleep.
Try CloudUp. It visits your apps periodically to keep them awake. It is free, and you can add as many apps as you want. It also activates apps on Google App Engine and Azure.

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