Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

phc: add metrics for number of unhealthy endpoints #3040

Draft
wants to merge 2 commits into
base: master
Choose a base branch
from
Draft

phc: add metrics for number of unhealthy endpoints #3040

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
2 commits
Select commit Hold shift + click to select a range
eafc71a
add metrics for number of unhealthy endpoints
MustafaSaber Apr 25, 2024
c11f4cd
Rename metric for better description
MustafaSaber Apr 26, 2024
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
3 changes: 2 additions & 1 deletion docs/operation/operation.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -925,7 +925,8 @@ while choosing the endpoint for the given request

A set of metrics will be exposed to track passive health check:

* `passive-health-check.endpoints.dropped`: Number of all endpoints dropped before load balancing a request, so after N requests and M endpoints are being dropped this counter would be N*M.
* Counter `passive-health-check.requests.dropped`: Number of all endpoints dropped before load balancing a request, so after N requests and M endpoints are being dropped this counter would be N*M.
* Gauge `passive-health-check.endpoints.dropped`: Number of unhealthy/filtered endpoints

## Memory consumption

Expand Down
2 changes: 1 addition & 1 deletion proxy/healthy_endpoints.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -25,7 +25,7 @@ func (h *healthyEndpoints) filterHealthyEndpoints(ctx *context, endpoints []rout
if p < dropProbability {
ctx.Logger().Infof("Dropping endpoint %q due to passive health check: p=%0.2f, dropProbability=%0.2f",
e.Host, p, dropProbability)
metrics.IncCounter("passive-health-check.endpoints.dropped")
metrics.IncCounter("passive-health-check.requests.dropped")
Copy link
Member Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Renamed this one, I think it's more descriptive right now

} else {
filtered = append(filtered, e)
}
Expand Down
5 changes: 4 additions & 1 deletion proxy/healthy_endpoints_test.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -175,8 +175,11 @@ func TestPHCForMultipleHealthyAndOneUnhealthyEndpoints(t *testing.T) {
failedReqs := sendGetRequests(t, ps)
assert.InDelta(t, 0, failedReqs, 0.1*float64(nRequests))
mockMetrics.WithCounters(func(counters map[string]int64) {
assert.InDelta(t, float64(nRequests), float64(counters["passive-health-check.endpoints.dropped"]), 0.3*float64(nRequests)) // allow 30% error
assert.InDelta(t, float64(nRequests), float64(counters["passive-health-check.requests.dropped"]), 0.3*float64(nRequests)) // allow 30% error
})
v, ok := mockMetrics.Gauge("passive-health-check.endpoints.dropped")
assert.True(t, ok, "passive-health-check.endpoints.dropped gauge not found")
assert.Equal(t, 1.0, v)
})
}

Expand Down
2 changes: 2 additions & 0 deletions proxy/proxy.go
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -539,8 +539,10 @@ func setRequestURLForDynamicBackend(u *url.URL, stateBag map[string]interface{})
func (p *Proxy) selectEndpoint(ctx *context) *routing.LBEndpoint {
rt := ctx.route
endpoints := rt.LBEndpoints
beforefiltering := len(endpoints)
endpoints = p.fadein.filterFadeIn(endpoints, rt)
endpoints = p.heathlyEndpoints.filterHealthyEndpoints(ctx, endpoints, p.metrics)
p.metrics.UpdateGauge("passive-health-check.endpoints.dropped", float64(beforefiltering-len(endpoints)))
Copy link
Member Author

@MustafaSaber MustafaSaber Apr 26, 2024 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

After some discussions with @RomanZavodskikh, this gauge will be overwritten by different services(requests), for example svc A has 2 unhealthy endpoints and svc B has 1 both will write on the same metric.

What we can do is append routeId or Name+Namespace combination. we aren't sure that's a good thing memory wise, wdyt @AlexanderYastrebov @szuecs?

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

From the 2 options the better is to use routeId, because Kubernetes data is 1) not available and 2) often not applicable (what about non-kubernetes dataclients?).
Another way would be to have passive-health-check.endpoints.dropped.<endpoint> and Gauge is 0 or 1 and then the query would be sum() to get all current dropped endpoints.

In any case it seems that we need to add some unbounded memory usage and we should think, if we need this at all or if we start by only logs that log the endpoint.


lbctx := &routing.LBContext{
Request: ctx.request,
Expand Down
Loading