1.9 KiB
Worker Utilization
This library is to be used when there are 1 or more worker threads accepting requests of some kind and servicing them. The goal is to provide a very simple way to monitor worker threads utilization, as a percentage of the time they are busy and the amount of requests served.
How to use
When a working thread starts, call:
void worker_register(const char *name);
This will create the necessary structures for the library to work.
No need to keep a pointer to them. They are allocated as __thread variables.
When the thread stops, call:
void worker_unregister(void)
Again, no parameters, or return values.
When you are about to do some work in the working thread, call:
void worker_is_busy(void)
When you finish doing the job, call:
void worker_is_idle(void)
Calls to worker_is_busy() can be made one after another (without calling
worker_is_idle() between them) to switch jobs without losing any time between
them and eliminating one of the 2 clock calls involved.
Implementation details
Totally lockless, extremely fast, it should not introduce any kind of problems to the workers.
Every time worker_is_busy() or worker_is_idle() are called, a call to now_realtime_usec()
is done and a couple of variables are updated. That's it!
The worker does not need to update the variables regularly. Based on the last status of the worker, the statistics collector of netdata will calculate if the thread is busy or idle all the time or part of the time. Works well for both thousands of jobs per second and unlimited working time (being totally busy with a single request for ages).
The statistics collector is called by the global statistics thread of netdata. So, even if the workers are extremely busy with their jobs, netdata will be able to know how busy they are.