Emit task metrics for single invocations instead of interval samples
declanvk opened this issue · 3 comments
Hello,
This is a feature request for some way to get the TaskMetrics for the invocation of a single future. Something like:
let monitor = tokio_metrics::TaskMonitor::new();
let (metrics, other_return_value) = monitor.instrument_single(some_future()).await;The API usage above is not intended to be the actual API, just illustrating the idea. I want this feature is so that I can record metrics for the overhead every single execution of the some_future() future.
The ultimate reason is that I'm trying to write a program that measures the latency of remote service calls, and I want to understand what kind of overhead I'm seeing as a result of using an async runtime, as opposed to a simple blocking thread application. I'd like to see this on a per-request basis so that I can confirm that requests with high latency are only the result of the remote system, not a result of a delay in scheduling the task.
The metrics library is not really the place for this. I recommend you check out the tracing crate.
Hi @declanvk, does this function satisfy your use case?
pub async fn with_metrics<F>(future: F) -> (tokio_metrics::TaskMetrics, F::Output)
where
F: std::future::Future
{
let monitor = tokio_metrics::TaskMonitor::new();
let future = monitor.instrument(future);
let result = future.await;
let metrics = monitor.cumulative();
(metrics, result)
}You can use it like:
let (metrics, other_return_value) = with_metrics(some_future()).await;