We currently have multiple Azure VMs all on the same virtual network. We would like to run a script, which, in case of failure restarts the services on a VM, but we would want to run that script on all vms at the same time (in parallel).
I have currently tried with runbook which works but it is not an option since it takes about 5 minutes to complete.
Another option seems to be with Invoke-Command but that would mean opening some ports (I am not sure if the endpoint needs to be opened since the machines are on the same virtual network) which is not very convenient.
Does someone has another idea maybe?
Related
I have a BE service in NestJS that is deployed in Vercel.
I need several schedulers, so I have used #nestjs/schedule lib, which is super easy to use.
Locally, everything works perfectly.
For some reason, the only thing that is not working in my production environment is those schedulers. Everything else is working - endpoints, data base access..
Does anyone has an idea why? is it something with my deployment? maybe Vercel has some issue with that? maybe this schedule library requires something the Vercel doesn't have?
I am clueless..
Cold boot is the process of starting a computer from shutdown or a powerless state and setting it to normal working condition.
Which means that the code you deployed in a serveless manner, will run when the endpoint is called. The platform you are using spins up a virtual machine, to execute your code. And keeps the machine running for a certain period of time, incase you get another API hit, it's cheaper and easier on them to keep the machine running for lets say 5 minutes or 60 seconds, than to redeploy it on every call after shutting the machine when function execution ends.
So in your case, most likely what is happening is that the machine that you are setting the cron on, is killed after a period of time. Crons are system specific tasks which run in the kernel. But if the machine is shutdown, the cron dies with it. The only case where the cron would run, is if the cron was triggered at a point of time, before the machine was shut down.
Certain cloud providers give you the option to keep the machines alive. I remember google cloud used to follow the path of that if a serveless function is called frequently, it shifts from cold boot to hot start, which doesn't kill the machine entirely, and if you have traffic the machines stay alive.
From quick research, vercel isn't the best to handle crons, due to the nature of the infrastructure, and this is what you are looking for. In general, crons aren't for serveless functions. You can deploy the crons using queues for example or another third party service, check out this link by vercel.
I have a Node.js web server which, as part of a CD process, I want to deploy to a staging server using Azure Release Pipeline. The problem is, that if I just run a Powershell script:
# Run-Server.ps1
node my-server.js
The Pipeline will hold since the node process blocks the Powershell session.
What I want is to be able to launch the service, and then in the next deployment just kill the node process and run it again with the new code.
So I figured I'll use Start-Process. If I run it locally:
> Start-Process node -ArgumentList ./server.js
I can now exit the Powershell session and the server will continue running. So I thought I can implement it the same way in my Release Pipeline.
But it turns out that once the Release Pipeline ends running, the server is no longer available - the node process is gone.
Can you help me figure out why is that? Is there another way of achieving this? I suppose it's a pretty common use case so there must be best-practices out there regarding to how this should be done.
Another way to achieve this is to use a full-blown web server to host andmanage node process. I.e. on Windows you could use IIS with iisnode module. This is more reliable and gives you a few other benefits:
process management (automatic start, restart on failure, etc.)
security - you can configure the user that node process will run as
scalability on multi-core CPUs
Then the process of app deployment would be just copying files to the right directory - the web server should pick up the change automatically.
By default, A pipeline job cleans up all of the child processes it spins up when it exits. This is killing your node server.
Set Process.Clean variable to false to override the default behavior.
I have a kind of a baseline machine on which I have run both the "Get-Process" and "Get-Service" cmdlets and saved their output in a file. These are the processes and services that are supposed to be running. What I am interested in is running these same commands again and save their outputs to a different file and then somehow compare these files to find if some new processes or services are running.
I want to find the new processes and services because it can help me identify any malicious activity on the servers. Is there anyway I can compare these and find the new processes and services.
Is it possible to run multiple Azure Self-hosted build/deploy agents and multiple deployment agents on one server? Also, can these agents service more than one organisation or even multiple Azure AD Tenants?
I do realise the consequences with the server straining under IO bottlenecks and the like, these agents will probably never have to manage more than 3 projects being build and/or deployed at a time, but the sources can be from different projects in different organisations or possibly Tenants.
I have deployed my Deployment Agents to the servers and they function fine with a Microsoft-hosted build agent (my question is about ONE of these servers, it would apply to all of them eventually), but I am afraid to now start deploying the build agents to the same servers now.
This approach is very Do-able and is actually really cost-effective if you do not have continuous deployments or your virtual machine has the IO capacity to handle the planed traffic.
Understand the basics of an Agent. What exactly happens when you host a Windows Agent is that it creates a Windows Service which would run internally a separate new process and perform the actions for the agent.
Since these are independent processes, they are not at all impacted by the operations of other agents. As long as you are not trying to access the same files/resources this approach is actually a great approach and we should surely try this.
I'm trying to write a Kotlin server with auto discovery, however I only have one computer to develop. My server uses a port and I just can't figure it out myself how to successfully test my application. Thanks for your help!
JVMs
You may be able to run copies of the app in different JVMs, but would have to run them on different ports.
VMs
This may be slow, but may be an option
Docker
Using Docker (and optionally compose) you been run multiple copies of the app on the same port, with less overhead than using full VMs.