Support:

1. environment variable HTTP_500_PERCENT to inject errors
2. modify locust to not use keep alive

kubernetes-manifests/frontend.yaml

@@ -63,6 +63,8 @@ spec:
             value: "checkoutservice:5050"
           - name: AD_SERVICE_ADDR
             value: "adservice:9555"
+          - name: HTTP_500_PERCENT
+            value: "3"
           # - name: JAEGER_SERVICE_ADDR
           #   value: "jaeger-collector:14268"
           resources:

src/frontend/handlers.go

@@ -45,11 +45,10 @@ func (fe *frontendServer) homeHandler(w http.ResponseWriter, r *http.Request) {
 	currencies, err := fe.getCurrencies(r.Context())
 
 	// NOTE: This artificially injects failures in a fixed percentage of the responess
-	if (rand.Intn(100) < 3) {
+	if (rand.Intn(100) < fe.errorRate) { 
 		renderHTTPError(log, r, w, errors.Wrap(err, "Random artificial 500 error"), http.StatusInternalServerError)
 		return
-	}
-	
+	} 
 	if err != nil {
 		renderHTTPError(log, r, w, errors.Wrap(err, "could not retrieve currencies"), http.StatusInternalServerError)
 		return

src/frontend/main.go

@@ -20,6 +20,7 @@ import (
 	"net/http"
 	"os"
 	"time"
+	"strconv"
 
 	"cloud.google.com/go/profiler"
 	"contrib.go.opencensus.io/exporter/stackdriver"
@@ -78,6 +79,8 @@ type frontendServer struct {
 
 	adSvcAddr string
 	adSvcConn *grpc.ClientConn
+
+	errorRate int
 }
 
 func main() {
@@ -110,6 +113,13 @@ func main() {
 	mustMapEnv(&svc.checkoutSvcAddr, "CHECKOUT_SERVICE_ADDR")
 	mustMapEnv(&svc.shippingSvcAddr, "SHIPPING_SERVICE_ADDR")
 	mustMapEnv(&svc.adSvcAddr, "AD_SERVICE_ADDR")
+	i, err := strconv.Atoi(os.Getenv("HTTP_500_PERCENT"))
+	if err == nil { 
+		svc.errorRate = i 
+		log.Infof("HTTP 500 Error Rate set to " + strconv.Itoa(svc.errorRate))
+	} else {
+		svc.errorRate = 0
+	}
 
 	mustConnGRPC(ctx, &svc.currencySvcConn, svc.currencySvcAddr)
 	mustConnGRPC(ctx, &svc.productCatalogSvcConn, svc.productCatalogSvcAddr)

src/loadgenerator/locustfile.py

@@ -29,25 +29,26 @@ products = [
     'OLJCESPC7Z']
 
 def index(l):
-    l.client.get("/")
+    l.client.get("/", headers={'connection': 'close'})
 
 def setCurrency(l):
     currencies = ['EUR', 'USD', 'JPY', 'CAD']
     l.client.post("/setCurrency",
-        {'currency_code': random.choice(currencies)})
+        {'currency_code': random.choice(currencies)}, headers={'connection': 'close'})
 
 def browseProduct(l):
-    l.client.get("/product/" + random.choice(products))
+    l.client.get("/product/" + random.choice(products), headers={'connection': 'close'})
 
 def viewCart(l):
-    l.client.get("/cart")
+    l.client.get("/cart", headers={'connection': 'close'})
 
 def addToCart(l):
     product = random.choice(products)
     l.client.get("/product/" + product)
     l.client.post("/cart", {
         'product_id': product,
-        'quantity': random.choice([1,2,3,4,5,10])})
+        'quantity': random.choice([1,2,3,4,5,10])},
+         headers={'connection': 'close'})
 
 def checkout(l):
     addToCart(l)
@@ -62,7 +63,7 @@ def checkout(l):
         'credit_card_expiration_month': '1',
         'credit_card_expiration_year': '2039',
         'credit_card_cvv': '672',
-    })
+    }, headers={'connection': 'close'})
 
 class UserBehavior(TaskSet):