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.
Related
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
I have recently deployed by nodejs ( with mongodb ) server on open shift which is being used by my android application. Every morning the first interaction from the app to the open-shift server always fails to get a response. After that any call made to the server always get a very fast response. I have a feeling that its sort of goes into sleeping mode because of no interaction from app to server for 8 hours or so (sleeping time)... I might be wrong . So I wish to know if someone has experienced that and if yes how do you resolve this . I do not get any logs at server for first call .
If you are using OpenShift Online Starter, you will find this behaviour explained on the product page.
https://www.openshift.com/products/online/
Quoting it:
Your project resources sleep after 30 minutes of inactivity, and must sleep 18 hours in a 72 hour period
OpenShift Online Starter is a free tier intended for experimentation and testing. It is not intended for production systems that need to be running permanently.
If you are running a production site, you would want to look at the Pro tier.
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 deployed node js server to Azure WebApp, and it worked fine. But, I see that sometime the response time is very slow. Also, I see that somewhere above 500 request/second the server start to fail handling request, and I see it use only 15% CPU. Now, I checked and the server return 500 error because the pipe is busy (by the win32 error code). That's why I was wondering if there is something I can change in the IISNode config to improve the server request capacity.
I already enabled the AlwaysOn feature, and also I add a check in Pingdom to keep the site alive. Also, I already changed nodeProcessCountPerApplication to 0 so it use all the available process.
Thank you,
Omer
One thing you can do is enable Always On. Without it, when your site hasn't been visited for 20 minutes the site gets taken down. Then the next time someone makes a request to your site Azure Web Apps warms up (re-sets up) your site but this process takes a few seconds.
Note that Always On is only available for sites in Basic, Standard, or Premium SKUs
Also, check out this page for tips on debugging Node.js apps in Azure Web Apps: https://azure.microsoft.com/en-us/documentation/articles/web-sites-nodejs-debug/
This question already has answers here:
Closed 10 years ago.
Possible Duplicate:
App pool timeout for azure web sites
I am working on an asp.net mvc 4 app that is hosted in Windows Azure. This app will not have a lot of traffic as people will intermittently (once an hour) use it. I wanted to try using Windows Azure.
My app is currently set to use the FREE web site mode. I noticed that after 30 minutes, the site takes a long-time (> 5 seconds) to load. After that initial load, its fast. Then, if someone doesn't use it for another 30 minutes, it takes >5 seconds to load again.
I then tried upping the web site mode to a SHARED instance. I experienced the same problem there.
I then tried upping the web site mode to a RESERVED instance. The problem then goes away.
While I'd like to use Windows Azure, paying $50+ a month for a RESERVED instance is pretty expensive for a site that few have used up to this point. However, I can't have the initial lag. That will just defer the few users I have. You could say you get what you pay for. At the same time, I have a hard time believing others are experiencing this problem and not complaining. There has to be something I'm missing.
I figure the problem has to deal with the application pool resetting. However, I can't seem to figure a way around this. Is anyone familiar with this issue? Is there a way to fix it on a FREE or SHARED instance?
Thank you!
This is expected behavior based on how Windows Azure Web Sites work. The app pool they live in is spun up "on demand" and then hangs around for a time period.
For a detailed (and shameless plug) you can check out my article on this: http://www.simple-talk.com/dotnet/.net-framework/windows-azure-websites-%e2%80%93-a-new-hosting-model-for-windows-azure/
In summary:
Web Sites are hosted in a process on a farm of machines running IIS. If a site is idle for some time then the process is torn down automatically. Also, if the box is seeing a lot of pressure due to the other sites on the box the idle timeout may come down quite a bit (even as low as five minutes). When the next call comes in you'll see the process spun up again (likely on a completely different server). This is because you are in a shared environment (and is similar to how Heroku works). Once you move to reserved then you are the ONLY person on that virtual machine and if you suffer from noisy neighbor issues in processing its' because of your own stuff.
There are ways to keep your site "up", such as having a job that pings the url frequently; however, given that the idle timeout is somewhat fluid it may not solve every case. You can check out a recent post by Sandrino on how to use Azure Mobile Services as a job scheduler: http://fabriccontroller.net/blog/posts/job-scheduling-in-windows-azure/ . There are also 3rd party services available that can do the ping for you automatically.
To be honest, the web sites are a great feature for quick development and test, or even relatively low traffic sites as you are talking about. If you need a high level of uptime and better performance then you'll want to look at Reserved, or another option if the cost isn't in line with expectations.
This isn't an Azure problem. It is a "feature" of any web site hosted in IIS. The default time-out for app pools is 20 minutes. Read about App Pool timeouts here - http://technet.microsoft.com/en-us/library/cc771956(v=ws.10).aspx - one method is to create a keep alive page and ping the page every 10 minutes or so.