What entry processes are
Entry processes count requests being handled simultaneously, not visitors. Why a slow site hits the limit long before a fast one does.
Your plan includes an entry process limit, and exceeding it produces a 503 error. Applies to shared and reseller hosting.
An entry process is a request currently being handled inside your account. The limit is how many can run at the same moment — not per hour, and not per visitor.
Why it is not a visitor limit
This is the most common misunderstanding, and it works in your favour.
A PHP request typically completes in a fraction of a second. The moment it finishes, the process ends and its slot is free. So a plan with 30 entry processes does not cap you at 30 simultaneous visitors — it caps you at 30 requests being processed at once, and each occupies its slot only briefly.
A site serving pages in 200 ms can handle far more than 30 concurrent visitors without ever approaching the limit.
Why slow sites hit it and fast ones do not
The corollary matters more:
The longer each request takes, the fewer visitors it takes to hit the limit.
A page taking 5 seconds holds its slot 25 times longer than one taking 200 ms. So the same traffic that a fast site absorbs comfortably will exhaust a slow site's entry processes — and once requests start queuing, pages get slower still, which holds slots even longer.
That feedback loop is why sites tend to fail suddenly rather than gradually.
Long-running work is the usual trigger:
- A cron job that takes minutes and runs every minute
- WP-Cron firing on page loads — see Replace WP-Cron with a real cron job
- A plugin making a slow external API call on every request
- A database query with no index
What happens at the limit
Requests above the limit are terminated by the kernel with SIGKILL. The visitor
sees a 503 Resource Limit Reached error.
Fixing it
Making pages faster raises effective capacity more than raising the limit does, because it frees slots sooner:
- Enable caching. A cached page never becomes an entry process at all — LiteSpeed Cache.
- Find what is slow — PHP X-Ray.
- Check Resource Usage in cPanel to see when the limit is being hit.
Full diagnosis in Fix a 503 Resource Limit Reached error.