So i found this on Heroku's help page: dyno sleeping and I am concerned about my bot being online 24/7 so I tested to see if that was true, and the good thing is that it wasn't! But thing is, is my bot making web requests? Because if you pay attention to the highlighted text, you can notice that it says that: "Apps that only utilise a free worker dyno do not sleep, because they do not respond to web requests. Be mindful of this as they may run 24/7 and consume from your pool of hours." I still changed the web dyno to worker dyno But i can't tell if it is working 24/7 even if I shutdown my PC So if someone know that answer for this question, please tell me.
Thank you.
When running a worker the process (in this case Discord Bot) runs in the background and it does not go to sleep (unlike free Web Dynos after 30 min inactivity.)
You can see the logs in your Heroku Dashboard (https://dashboard.heroku.com/apps/{app_name}/logs, you should see some activity and definitely the process not terminating.
Related
I have a REST api node app.
Once its running on localhost, it runs until I stop the dev debugging, no errors.
I moved it over to my cPanel hosting, installed a node app.
It starts up the same as localhost.
But after 30 minutes being idle, it shuts down.
The next request after this, restarts the app.
There are no crash or errors in the log, just the restarting messages.
I know this is default behaviour for free hosting, like Heroku but I'm paying for this hosting package.
Does anyone know...
Is this default behaviour for cPanel hosted node apps, or is my app causing this (using too much memory or cpu for example?
Is there any settings that can be edited to change this?
According to the docs, cPanel uses something called Phusion Passenger to run Node.js. In turn, Passenger docs show a default "idle time" of 5 minutes and a default of passenger_min_instances = 1. No idea if cPanel changes the defaults, or if the hosting provider did. I would recommend contacting the hosting provider about the issue in any case, and asking about these options specifically - they may be able to help or tune the service for you.
The startup time for a node app depends on what it's doing. A rest-api could be in the milliseconds, whereas a small Ai app loading a corpus or training a dataset (which mine was) could end up being 30 seconds plus. However the quantity of users did not warrant a dedicated server, so the work-around was to call the endpoint using a CRON, keeping the app alive.
Not perfect, but this type of thing may be useful if you are using aws lambda, which calls a 3rd party service, and which charges based on time taken. Every millisecond counts.
I have a Parse Server which is a Node.js + express wrapper for a mobile app (about 100 simultaneous users every day), hosted on DigitalOcean. The app server communicates with MongoDB, which is hosted on another droplet of DigitalOcean. I'm using pm2 as a process manager and its monitoring tool, which is web-based. On the same process, we operate LiveQuery, a WebSocket server made by the Parse community as well.
The thing is, I've been having some performance issues with the server. Everything works smoothly, until the Active handles rise up uncontrollably! (see the image below) It's like after one point the server says "I'm done! Now I rest!"
Usually the active handles stay between 30 to 70. The moment I restart the process with pm2 restart everything goes back to normal!
I've been having this issue for quite some time now and I haven’t been able to figure out what’s causing it! Any help will be greatly appreciated!
EDIT: I did a stress test where I created 200 LiveQuery sockets for 1 user, instead of 2 that a user normally has and there was a spike of 300 active handles, for like 5 seconds! The moment the sockets were all created, everything went back to normal!
I usually use restart based on memory usage
pm2 start filename.js --max-memory-restart 160 --exp-backoff-restart-delay=100
pm2 has also built-in cron job or autostart script setup in case the server ever restarts, see https://pm2.keymetrics.io/docs/usage/restart-strategies/
it would be could if pm2 would provide restart options based on active connections or heap memory
Heroku reboots servers everyday. After reboot, my node server takes around 20 seconds to load a page for the first time. Is there a way to prevent this?
EDIT: You guys seem to be misunderstanding the situation. In Heroku, even production servers must be restarted daily. This is not the same as a free server sleeping. This question is aimed more at preventing lazy-loading and pre-establishing connection pools to databases.
Old question, but in case others stumble upon it like I did
Use can use Heroku's Preboot feature:
Preboot changes the standard dyno start behavior for web dynos. Instead of stopping the existing set of web dynos before starting the new ones, preboot ensures that the new web dynos are started (and receive traffic) before the existing ones are terminated. This can contribute to zero downtime deployments
You could also combine it with a warmup script like the one described in this Heroku post
I'm running my blog on an Heroku dyno, and too many times my users have to wait almost half a minute for my blog to respond. There are ways to prevent Heroku from idling: Easy way to prevent Heroku idling? Most obvious is to ping the server every minute or so.
But it seems those methods are against Heroku's TOS, if I check the pricing page: https://www.heroku.com/pricing (see MUST SLEEP 6 HOURS IN A 24 HOUR PERIOD). And because Pingdom does costs me some money as well, I'm thinking of paying $7 dollars a month for the Hobby package. But how many apps can you run with that package? Cause I always run one app per dyno, but if I have to pay $7 per app... That seems too much.
Anyone who knows there is a way to run multiple apps on a dyno? Or is hiring a server at DigitalOcean with NodeJS a better choice, for example?
The free and hobby dyno types only support a maximum of one dyno running per process type. Additionally, applications using a free dyno type are limited to a maximum of two concurrent running dynos.
By default, a process type can’t be scaled to more than 100 dynos for standard-1X or standard-2X sized dynos. A process type can’t be scaled to more than 10 dynos for performance dynos.
We are running NodeJS server on Heroku. we want to know whether heroku will restart the application if application crashes. Also will there any different behavior between free version and paid version?
It will. For several times, and then "cool off" for ten minutes and try again. From the docs:
Heroku’s dyno restart policy is to try to restart crashed dynos by spawning new dynos once every ten minutes. This means that if you push bad code that prevents your app from booting, your app dynos will be started once, then restarted, then get a cool-off of ten minutes. In the normal case of a long-running web or worker process getting an occasional crash, the dyno will be restarted instantly without any intervention on your part. If your dyno crashes twice in a row, it will stay down for ten minutes before the system retries.
The docs: https://devcenter.heroku.com/articles/dynos#automatic-dyno-restarts
EDIT Regarding free dynos: the restart behavior is the same. However, there is something called "Dyno Idling" which happens only in free dynos. Basically it means that if your dyno does not receive any request for 1 hour it will "go to sleep", and the next request will "wake it up", which will cause that next request to be slightly delayed. This happens only when you have 1 free web dyno for your app.
To circumvent that, either have 2 dynos (and then none of them will idle, but you will be paying for one), or have "something" poll your web dyno every (say) 30 minutes. Like pingdom, say.
The docs: https://devcenter.heroku.com/articles/dynos#automatic-dyno-restarts
Fast-forward to 2022, Go to your app on the Heroku portal
Click on "More" dropdown
Select "Restart all dynos"