Update tileer load test script

CHANGELOG.md

@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ### Changed
 
 - Update DB anonymization script [#1769](https://github.com/open-apparel-registry/open-apparel-registry/pull/1769)
+- Update tileer load test script [#1770](https://github.com/open-apparel-registry/open-apparel-registry/pull/1770)
 
 ### Deprecated
 

load-tests/README.md

@@ -8,6 +8,7 @@ components necessary to execute a load test are encapsulated in this directory.
 
 - `K6_CLOUD_TOKEN`: An Auth Token for interacting with the k6 Cloud (optional)
 - `CACHE_KEY_SUFFIX`: A suffix to append in the path to ensure tile requests miss the cache (optional)
+- `VU_MULTIPLER`: An integer number of parallel executions of each batch of requests
 
 ## Running
 
@@ -59,11 +60,21 @@ default ✓ [======================================] 10 VUs  01m38.9s/10m0s  10/
 ERRO[0101] some thresholds have failed
 ```
 
+To invoke an instance of the load test running with 10 times the number of
+parallel requests and a random cache key suffix to avoid CloudFront
+
+```console
+VU_MULTIPLIER=10 \
+CACHE_KEY_SUFFIX=$(echo $(date) | sha1sum | cut -c1-8) \
+docker-compose -f docker-compose.yml run --rm \
+  k6 run /scripts/zoom_rio_de_janerio_with_contributor_filter.js
+```
+
 To invoke an instance of the load test streaming output to the k6 Cloud:
 
 ```console
 $ export K6_CLOUD_TOKEN=...
 $ docker-compose \
-    -f docker-compose.k6.yml \
-    run --rm k6 run -o cloud scripts/zoom_rio_de_janerio_with_contributor_filter.js
+    -f docker-compose.yml \
+    run --rm k6 run -o cloud /scripts/zoom_rio_de_janerio_with_contributor_filter.js
 ```

load-tests/docker-compose.yml

@@ -5,6 +5,7 @@ services:
     environment:
       - K6_CLOUD_TOKEN
       - CACHE_KEY_SUFFIX
+      - VU_MULTIPLIER
     volumes:
       - ./:/scripts/
     command: run /scripts/zoom_rio_de_janerio_with_contributor_filter.js

load-tests/zoom_rio_de_janerio_with_contributor_filter.js

@@ -24,9 +24,14 @@ har.log.entries.forEach((entry) => {
     const cacheKey = crypto
         .sha1(entry.request.url.match(pattern)[5], "hex")
         .slice(0, 8);
+    // Including the __VU in the cache key should generate a worse situation
+    // than typical. Each batch of requests is made by a separate VU and when
+    // VU_MULTIPLIER is larger than 1, we repeat the same batch of requests a
+    // number of times equal to VU_MULTIPLIER. Using __VU in the cache key means
+    // subsequent requests for the same batch will not hit the cache.
     const url = entry.request.url.replace(
         pattern,
-        `${cacheKey}${__ENV.CACHE_KEY_SUFFIX}/$2/$3/$4.pbf?$5`
+        `${cacheKey}-vu-${__VU}-${__ENV.CACHE_KEY_SUFFIX}/$2/$3/$4.pbf?$5`
     );
 
     const referer = entry.request.headers.find(
@@ -63,11 +68,13 @@ batches = batches.sort((a, b) => a - b);
 
 const failRate = new Rate("failed requests");
 
+const VU_MULTIPLIER = __ENV.VU_MULTIPLIER || 1;
+
 export const options = {
     // We want VUs and iterations to match the number of parallel request
     // batches we're going to issue so we can replay traffic 1:1.
-    vus: batches.length,
-    iterations: batches.length,
+    vus: batches.length * VU_MULTIPLIER,
+    iterations: batches.length * VU_MULTIPLIER,
 
     discardResponseBodies: true,
     maxRedirects: 0,
@@ -79,7 +86,8 @@ export const options = {
 export default function () {
     // Sleep each Batch so that everything doesn't happen at once
     const firstBatchTime = batches[0];
-    const thisBatchTime = batches[__VU - 1];
+    const batchIndex = (__VU - 1) % batches.length;
+    const thisBatchTime = batches[batchIndex];
     sleep(Math.floor((thisBatchTime - firstBatchTime) / 1000));
 
     const responses = http.batch(requests[thisBatchTime]);