CODEWITHSUNDEEP
node.js
LuckyLuke
LuckyLuke

Reputation: 1054

How to ensure node.js process will run on different thread?

So for example there would be service 1 that runs on http://127.0.0.1:5000 that runs on thread 1.

And I would like to run service 2 that would run on http://127.0.0.1:5001 that would run on any thread but not on thread 1.

Is it possible to do something like that?

Upvotes: 1

Views: 484

Answers (1)

jfriend00
jfriend00

Reputation: 707328

First off, I think you meant to say "CPU core" instead of "thread". Code runs in a thread and a thread runs on a CPU core when it is running. A process may contain one or more threads. In fact, a nodejs process contains several threads, one thread for running your Javascript, but other threads are involved in running the overall nodejs process.

Which CPU core a given thread runs on is up to the operating system.

Normally with a multi-core CPU, two processes that are trying to run at the same time will be assigned to different CPU cores. This is a dynamic thing inside the OS and can change from time to time as different threads/processes are time sliced. Processes of any kind (including nodejs processes) are not hard bound to a particular core and threads within those processes are not hard bound to a particular core either.

The operating system will decide based on which threads in which processes are vying for time to run how to allocate CPU cores to each thread and it is a dynamically changing assignment depending upon demand. If more threads are trying to run than there are cores, then the threads will each get slices of time on a CPU core and they will all share the CPU cores, each making progress, but not getting to hog a CPU core all to themselves.

If your two services, one running on port 5000 and one running on port 5001 are both nodejs apps, then the operating system will dynamically allocate CPU cores upon demand to each of them. Neither of those two service processes are bound to a specific core. If they are both heavily busy at the same time and you have a multi-core CPU and there's not a lot else in computer also contending for CPU time, then each service's main thread that runs your Javascript will have a different CPU core to run on.

But, keep in mind that this is a dynamic assignment. If you have a four core CPU and all of a sudden several other things start up on your computer and are also contending for CPU resources, then the CPU cores will be shared across all the threads/processes contending for CPU resources. The sharing is done via rotation in small time slices and can incorporate a priority system too. The specific details of how that works vary by operating system, but the principle of "time-sharing" the available CPU cores among all those threads requesting CPU resources is the same.

Upvotes: 3

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