Lower upstream count for scale nfr test with nginx plus (#2695)

Problem: We were running into infrequent test failures due to nginx plus running out of memory when scaling upstreams.

Solution: Lower the upstream count when running with nginx plus by 2% of the previous maximum. Will monitor future NFR runs to see if this issue persists.

Testing: Ran the nfr scale test and it passed.

tests/README.md

@@ -276,7 +276,7 @@ required env vars. `GKE_SVC_ACCOUNT` needs to be the name of a service account t
 
 In order to run the tests in GCP, you need a few things:
 
-- GKE router to allow egress traffic (used by upgrade tests for pulling images from Github)
+- GKE router to allow egress traffic (used by upgrade tests for pulling images from Github, and scale/reconfig tests for installing prometheus)
   - this assumes that your GKE cluster is using private nodes. If using public nodes, you don't need this.
 - GCP VM and firewall rule to send ingress traffic to GKE
 
@@ -286,6 +286,12 @@ To just set up the VM with no router (this will not run the tests):
 make create-and-setup-vm
 ```
 
+To set up just the router:
+
+```makefile
+make create-gke-router
+```
+
 Otherwise, you can set up the VM, router, and run the tests with a single command. See the options below.
 
 By default, the tests run using the version of NGF that was `git cloned` during the setup. If you want to make

tests/suite/scale_test.go

@@ -59,7 +59,7 @@ var _ = Describe("Scale test", Ordered, Label("nfr", "scale"), func() {
 		httpsListenerCount      = 64
 		httpRouteCount          = 1000
 		ossUpstreamServerCount  = 648
-		plusUpstreamServerCount = 556
+		plusUpstreamServerCount = 545
 	)
 
 	BeforeAll(func() {
@@ -441,7 +441,7 @@ The logs are attached only if there are errors.
 
 			Eventually(
 				framework.CreateResponseChecker(url, address, timeoutConfig.RequestTimeout),
-			).WithTimeout(30 * time.Second).WithPolling(100 * time.Millisecond).Should(Succeed())
+			).WithTimeout(5 * timeoutConfig.RequestTimeout).WithPolling(100 * time.Millisecond).Should(Succeed())
 
 			ttr := time.Since(startCheck)
 
@@ -475,7 +475,7 @@ The logs are attached only if there are errors.
 
 		Eventually(
 			framework.CreateResponseChecker(url, address, timeoutConfig.RequestTimeout),
-		).WithTimeout(5 * time.Second).WithPolling(100 * time.Millisecond).Should(Succeed())
+		).WithTimeout(5 * timeoutConfig.RequestTimeout).WithPolling(100 * time.Millisecond).Should(Succeed())
 
 		Expect(
 			resourceManager.ScaleDeployment(namespace, "backend", upstreamServerCount),
@@ -488,7 +488,7 @@ The logs are attached only if there are errors.
 
 		Eventually(
 			framework.CreateResponseChecker(url, address, timeoutConfig.RequestTimeout),
-		).WithTimeout(5 * time.Second).WithPolling(100 * time.Millisecond).Should(Succeed())
+		).WithTimeout(5 * timeoutConfig.RequestTimeout).WithPolling(100 * time.Millisecond).Should(Succeed())
 	}
 
 	setNamespace := func(objects framework.ScaleObjects) {