When the dump file was imported, the first graph and data table made it very obvious that we had a memory leak. A file logger was using 90% of the memory, equivalent to 3.5GB. Remember that high memory usage doesn’t always mean that there’s a memory leak. The problem is that the memory increases linearly over time, and without it dropping back to its normal consumption. This isn’t the only application of the InMemory provider, though.
Environment.ProcessorCount is set by .NET Core depending on how much CPU docker gives you. CPU is specified in millicores, for example 300mi och 2500mi. It will truncate the value and that will be your number of Environment.ProcessorCount. I will soon explain more details why this matters and what it affects. Some services which were supposed to be singletons were scoped, so I fixed this too.
The switch can be done by adding this flag to our csproj file. So why try to reproduce the problem when it’s already occurring in a production environment? Most of the bugs can’t, or hard to, look into a production environment. While being impressed with these tools, I wasn’t able to reproduce the memory leak locally despite my effort to mimick the traffic towards the API with Artillery.
Setting The Container Image And Registry
Threads are expensive, and the ThreadPool is good at handling lots of Task’s with a few threads. The ThreadPool therefore – when needed – gives you roughly 1 more thread each 0.5 seconds on demand. This is because the .NET Core runtime doesn’t want to allocate hundred of threads just because of a traffic spike. It seems the ThreadPool is very efficient anyway, so you shouldn’t need that many more threads to handle quite more traffic (as long as you’re using async/away correct in your code of course!). Remember those .Result nightmare-calls that blocks the thread. What docker tells your Linux container is then what the .NET Core runtime will read and take decisions on.
- I do believe there are some practises that are generally more accepted , but it’s really hard to know the „best“ configuration values for the rest.
- Resource governance in Service Fabric is used to control the “noisy neighbour” problem of services that consume too many resources and starve other services.
- I actually found a .Result as part of a call in our login code.
- After every successful step executed, the previous container is removed.
- Environment.ProcessorCount is set by .NET Core depending on how much CPU docker gives you.
It needs to be used to store coredump.1 The directory of the file is mounted to the container , Or yourself cp go in . [[email protected] Diagnostic_scenarios_sample_debug_target]# docker build -t dumptest . The example contains leaked memory 、 Deadlock thread 、CPU It’s taking too much of an interface , Easy to learn .
Seeding With Test Data On Startup
Unfortunately I don’t have any graphs for when limit was 300MB. Yes, thanks, this works to some extent but what I see is that the containers are not using less memory, the memory just moves into swap which degrades the performance of the API. I appreciate it if you would support me if have you enjoyed this post and found it useful, thank you in advance.
At this point, you can create additional service and start containers on this machine, provided you open ports on the VM with the procedure described above. This will be the part with the least focus in this article, since we have covered building ASP.NET Core applications for a while now and you can find a lot resources on this topic, including some on this site. Then, we will configure an Azure VM to be a node for Docker Cloud and Docker Cloud will automatically publish containers to that VM.
A Service Fabric application is analogous to the Kubernetes pod in that it is the main unit of scaling that can host one or more containers. You use the SDK templates to create a project that deploys one or more container to a cluster. Given the recent rise of services such as Azure Kubernetes Service, the container support in Service Fabric seems to be targeted more towards lifting and shifting existing .Net applications. You can use it as an orchestrator for cloud-native services, but you are inevitably made to feel like a second-class citizen in doing so. The process of configuring and deploying container-based applications to Service Fabric does not compare well with a “pure” orchestrator like Kubernetes. Just look at the call stack , It’s too hard to see the problem …
This makes it possible to prototype applications and write tests without having to set up a local or external database. When you’re ready to switch to using asp net usage a real database, you can simply swap in your actual provider. You can host containers in Service Fabric, but it is first and foremost an application server.
Now if you go to Docker Hub you should see your newly created image. You can clearly see how each step in the Dockerfile is executed successively and how at every step an intermediate container gets created. This is done so that if the execution fails at let’s say STEP 7, all progress made up to that point doesn’t get lost. After every successful step executed, the previous container is removed.
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An IsServiceFabricServiceProject element is added to the project file. Landing Your AWS Journey With Control Tower You can think of AWS Control Tower as an orchestra director that leverages various AWS services to create a foundation for your multi-account architecture. Type ‚help‘ to list available commands or ‚help ‚ to get detailed help on a command. Tools directory ‚/root/.dotnet/tools‘ is not currently on the PATH environment variable.
Configure the Service From here, give the service a name, set the initial number of containers, expose/publish ports, modify the run command or entrypoint, set memory and CPU limits. By now, the GitHub repository with the application should be up to date, since we will use it to create a new Docker Cloud repository that will automatically build images on every git push in the GitHub repo. While Docker Cloud allows you to run containers and build images on some free tier servers, you would most likely want to do it on your own machine.
I am a London-based technical architect who has spent more than twenty five years leading development across start-ups, digital agencies, software houses and corporates. Over the years I have built a lot of stuff including web sites and services, systems integrations, data platforms, and middleware. My current focus is on providing architectural leadership in agile environments. Perhaps Service Fabric’s support for containers could be seen in the context of supporting a longer-term migration strategy. If you’ve already made a significant investment in Service Fabric, then you can start to migrate towards a more “cloud native” style of service without having to replace your runtime infrastructure.
I have reviewed the Docker container memory use question but it’s different, and has no answer at this point.
Troubleshooting High Memory Usage With Asp Net Core On Kubernetes
You’ll notice in the snippet above, the URL of the Seq server is hard-coded. URLs, API keys, etc. will commonly vary between your local development environment, and your app’s staging or production environments. If you usually have bursts of traffic at different times you might want to increase the miniumum amount of threads the ThreadPool can create on demand. By default the ThreadPool will only create Environment.ProcessorCount number of threads on demand. These things are essential to know when trying to understand memory usage and „wellbeing“ of you application, so I thought i’ll mention them.
Deploying Asp Net Core And Ef Core To Docker On Azure Using Visual Studio 2017
I also knew we had some very strange usage of async/await code, but I hadn’t had time to fix it. I actually found a .Result as part of a call in our login code. Another metric we noticed during our spike window was that the memory for the pods shut through the roof. We had to restart the pods in order for the memory to go back to normal. So it felt like we really had some memory troubles in our code.
Best Practices For Setting Up Azure Devops Projects With Git
Use dotnet restore to install the package if you aren’t using Visual Studio. Real world scenarios would most certainly involve more containers, so composing and orchestrating containers, as well as testing. At this point, you should be able to SSH into the machine and install the Docker Cloud agent.
Then, every time there are changes in the GitHub repository, Docker Cloud will build the image and publish the container again automatically. In particular, check out the Serilog.AspNetCore README, which has details on some features like IDiagnosticContext and LoggerProviderCollection that I wanted to mention, but didn’t have space to write about here. The project repository also contains some example applications much like the one we’ve been using in this post. What about changing logging configuration without redeploying? — So, fiddling with configuration files in notepad over RDP is rarely a good idea. With continuous integration, and an automated deployment system (like Octopus Deploy!) to make deployment of fully-tested code changes quick and easy, this can be avoided.
Setting Up Serilog In Asp Net Core 3
Adopt setthread The command switches the thread to 0x1e8 On , And then use clrstack Look at its call stack . So, it’s easy to find information about similar problems but it’s very hard to find a single „right“ configuration for all these values. One thing is for sure however – do look through all your code and search for .Result and Task.Run for example. Also remove all your in-memory caches because they eat memory, even in low-resource environments such as k8s and in-memory cache must have it’s own cache per pod of course, which kinda destroys the purpose of a cache. When k8s starts your container it will give it some CPU and memory limits . The GC in .NET Core works differently depending on CPU and memory limits.
In a previous blog post I showed you how you can setup unit tests to run in memory when testing ASP.NET Core & EF Core applications. But what about when you want to deploy a new application built on .NET Core. In this post I outline the steps that are needed in order to build and deploy an ASP.NET Web API application to a Docker container hosted in Azure. I will walk through the steps needed to do a deployment into a new Docker Container, using Visual Studio 2017, along with a new set of Azure SQL databases. Note, the process outline here is very simple and will not scale beyond an individual developer’s prototype environment, so consider this a simple introduction rather than a full solution for a team project. When you first deploy an application, be prepared for Service Fabric to report that the service is unhealthy while it downloads and installs the container image.
So in my previous post, I had separated the different layers into separate projects, however, when deploying through VS2017 I encountered some limitations in the Visual Studio tooling for Entity Framework Core (1.0) migrations. Essentially doing data migrations for projects outside of the current deployed project do not play well. I am sure this is because these are still relatively early days for EF Core and the tooling will eventually catch up, but for now everything in the sample is pretty much in one project and organized in data folders. In the meantime, just to mitigate the continuous restarts of our containers we increased the memory limit from 500MB to 1000MB, which led to an interesting find. After increasing the limit, the memory usage of the containers looked like this.
Troubleshooting Deployment Issues
Since this is a .NET Core application, I chose to add a .gitignore file that will ignore all .NET specific output files after building the application. Clicking on an event to expand it, as I’ve done above, will show all of the information that ASP.NET Core is recording behind the scenes. Clicking on the green check-mark beside RequestId, and choosing Find, demonstrates the power of structured logging when dealing with a lot of log output.
This means that for this web application to have a good throughput we cannot queue up too many dependency calls. This lead me into reading about the ThreadPool, because it is related to how many requests you can handle. It also lead me into reading about the ServicePointManager, because one of all things it control is the number of concurrent outgoing dependency calls you can make. This was a pretty clear indication that we are not actually leaking, but simply a lot of memory is being allocated without any of it getting released. So I started looking into what .NET thinks its memory limit is when running in Kubernetes. These graphs show the memory usage of two of our APIs, you can see that they keep increasing until they reach the memory limit, when Kubernetes restarts them.
The Serilog configuration above is fairly self-explanatory. I’ve added Enrich.FromLogContext() to the logger configuration since we’ll use its features later on, and forgetting to enable it is a frequent cause for head-scratching when events are missing expected properties like RequestId. Serilog is also independent of .NET Core and most of the framework infrastructure , making it well-suited to collecting and recording problems with starting up the framework itself, which is a critical role for a logging library. The most difficult aspect of running a container application to work is in getting a Service Fabric cluster up and running in the first place. The tooling does not feel particularly mature and troubleshooting it can be a frustrating experience. Element where you specify an image that is hosted in a container registry, i.e.
Copyright © 2020 Using dotnet dump to analyze the memory leak of docker container All Rights Reserved. There’s a lot of different things of course that affects the amount of memory your application uses, and I wasn’t sure what was reasonable. The threshold of 300MB wasn’t even set by our team either, so we had to investigate what memory limit is reasonable for a ASP.NET Core 3.1 application and what people „normally“ use in k8s. This lead me to read about what limits are reasonable for an ASP.NET Core application. To create a dump file, use the dotnet dump collect command, or if you can log in on the server by opening the task manager, right-clicking on a process, and selecting „Create a dump file“.