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by kbolino 5164 days ago
What is it wasting? If the process is idle, then it is only taking up space in memory.

If that space isn't needed, then the cost is nil (it takes the same amount of power to store a 1 as a 0; the real power cost is in moving data in and out of memory, not in storing it).

If the space is needed, then the idle process can be swapped out to disk. So again, no practical cost.

FastCGI may not be the best solution, but CGI is not an improvement (the overhead of starting a new runtime to handle every request will introduce a lot of latency, which will be especially noticeable on pages that make a lot of asynchronous requests).
1 comments
DougBTX 5164 days ago
> then the idle process can be swapped out to disk.

If the FastCGI process is swapped out, does it still have a performance benefit?

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kbolino 5164 days ago
Caveat: As they say, one good test is worth a thousand expert opinions, and I'm no expert.

I'm inclined to say yes, it would still have a benefit. My thoughts:

- Swapping the FastCGI process back in shouldn't be any worse than loading a CGI process cold and initializing it (disk caching will probably be no help to CGI here: with so little free memory, the cache will be small or nonexistent and aggressively purged);

- Once swapped in, the FastCGI process will be able to handle multiple requests in less time and less memory than it would take just to start the many CGI processes necessary to do the same work.

Also, if the performance of your server is an issue, your FastCGI process should never be in a situation where it would be swapped out. You need to add more memory, and/or reduce the other loads on your server.

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