如何在 C# 中创建高效的后台任务？

Question

I am fairly new to asynchronous programming so I need help.

What I need to do is, create a windows service that constantly checks the database for menu updates (insert/updates), tables updates (insert/updates), menu category updates (insert/updates) and so on and if any change is detected the service will then need to POST those said changes to separate APIs one by one. Keeping in mind that the service will be used for just this purpose and the database that I need to check for updates is SQL Server.

So, how do I approach this scenario efficiently ? Do I create new Tasks (System.Threading.Tasks) or create new Threads (System.Threading.Thread) for each pieces like UpdateMenu that checks the menu updates and upload to api, UpdateTable, UpdateDishes and so on and how do I go about the Posting to the API part I mean do I create a new Task for each and every API call? I want the application to be as efficient as possible and pick the changes and post them to API as soon as possible.

Thanks in advance.

Answer 1

It seems that you are worried about the overhead of the mechanism that you are going to use, in order to fetch data from the database and post these data to APIs. You are thinking that maybe Thread s are fast and Task s are slower, or vice versa. In fact choosing between these two mechanisms is likely to have no measurable impact to your service's demand for CPU, memory or other system resources.

What is likely to be impactful, is the pattern of communication of your service with the database and the APIs. For example if your threads/tasks are not coordinated with each other, and query the database all at the same time, the database might be slow to respond, and might consume larger amounts of memory while preparing the response. That's not because your threads/tasks are slow. It's because your service is querying the database with a pattern that makes it harder for the database to respond. The same might be true for the pattern of communication with the APIs. If your workers are not coordinated, the network connectivity might become a bottleneck, or the remote machines that host the APIs might suffer.

So my advice is to focus on the usability factor of the mechanisms, and not on their supposed difference in performance. If you are comfortable and familiar with threads, and know nothing about tasks, use threads. If you are familiar with both threads and tasks, use tasks because they are generally easier to use. You'd better invest your time to optimize the communication pattern between your service and its dependencies, than for doing benchmarks trying to find the best between mechanisms that for all intents and purposes are equally efficient.