From: Tom Clegg <tom@curii.com>
Date: Mon, 12 Jun 2023 18:47:30 +0000 (-0400)
Subject: 20602: Add IneligibleForQueuePriority const.
X-Git-Tag: 2.7.0~83^2
X-Git-Url: https://git.arvados.org/arvados.git/commitdiff_plain/refs/heads/20602-controller-qos

20602: Add IneligibleForQueuePriority const.

Arvados-DCO-1.1-Signed-off-by: Tom Clegg <tom@curii.com>
---

diff --git a/lib/service/cmd.go b/lib/service/cmd.go
index 37eac86d25..c66c279432 100644
--- a/lib/service/cmd.go
+++ b/lib/service/cmd.go
@@ -10,7 +10,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"math"
 	"net"
 	"net/http"
 	"net/http/httptest"
@@ -262,7 +261,7 @@ func (c *command) requestPriority(req *http.Request, queued time.Time) int64 {
 		// Return 503 immediately instead of queueing. We want
 		// to send feedback to dispatchcloud ASAP to stop
 		// bringing up new containers.
-		return math.MinInt64
+		return httpserver.IneligibleForQueuePriority
 	case req.Method == http.MethodPost && strings.HasPrefix(req.URL.Path, "/arvados/v1/logs"):
 		// "Create log entry" is the most harmless kind of
 		// request to drop.
diff --git a/sdk/go/httpserver/request_limiter.go b/sdk/go/httpserver/request_limiter.go
index 402de3e10c..cd928e6ea8 100644
--- a/sdk/go/httpserver/request_limiter.go
+++ b/sdk/go/httpserver/request_limiter.go
@@ -15,6 +15,8 @@ import (
 	"github.com/sirupsen/logrus"
 )
 
+const IneligibleForQueuePriority = math.MinInt64
+
 // RequestLimiter wraps http.Handler, limiting the number of
 // concurrent requests being handled by the wrapped Handler. Requests
 // that arrive when the handler is already at the specified
@@ -194,7 +196,7 @@ func (rl *RequestLimiter) enqueue(req *http.Request) *qent {
 		ent.ready <- true
 		return ent
 	}
-	if priority == math.MinInt64 {
+	if priority == IneligibleForQueuePriority {
 		// Priority func is telling us to return 503
 		// immediately instead of queueing, regardless of
 		// queue size, if we can't handle the request
diff --git a/sdk/go/httpserver/request_limiter_test.go b/sdk/go/httpserver/request_limiter_test.go
index fd09c9305a..b04ff57cc1 100644
--- a/sdk/go/httpserver/request_limiter_test.go
+++ b/sdk/go/httpserver/request_limiter_test.go
@@ -6,7 +6,6 @@ package httpserver
 
 import (
 	"fmt"
-	"math"
 	"net/http"
 	"net/http/httptest"
 	"strconv"
@@ -135,14 +134,14 @@ func (*Suite) TestRequestLimiterQueuePriority(c *check.C) {
 		<-h.inHandler
 	}
 
-	c.Logf("starting %d priority=MinInt64 requests (should respond 503 immediately)", rl.MaxQueue)
+	c.Logf("starting %d priority=IneligibleForQueuePriority requests (should respond 503 immediately)", rl.MaxQueue)
 	var wgX sync.WaitGroup
 	for i := 0; i < rl.MaxQueue; i++ {
 		wgX.Add(1)
 		go func() {
 			defer wgX.Done()
 			resp := httptest.NewRecorder()
-			rl.ServeHTTP(resp, &http.Request{Header: http.Header{"Priority": {fmt.Sprintf("%d", math.MinInt64)}}})
+			rl.ServeHTTP(resp, &http.Request{Header: http.Header{"Priority": {fmt.Sprintf("%d", IneligibleForQueuePriority)}}})
 			c.Check(resp.Code, check.Equals, http.StatusServiceUnavailable)
 		}()
 	}