Put max flush size behind remote config flag

Author: raymondlam

packages/performance/src/services/remote_config_service.test.ts

@@ -40,7 +40,8 @@ describe('Performance Monitoring > remote_config_service', () => {
   "fpr_log_endpoint_url":"https://firebaselogging.test.com",\
   "fpr_log_transport_key":"pseudo-transport-key",\
   "fpr_log_source":"2","fpr_vc_network_request_sampling_rate":"0.250000",\
-  "fpr_vc_session_sampling_rate":"0.250000","fpr_vc_trace_sampling_rate":"0.500000"},\
+  "fpr_vc_session_sampling_rate":"0.250000","fpr_vc_trace_sampling_rate":"0.500000",
+  "fpr_log_max_flush_size":"10"},\
   "state":"UPDATE"}`;
   const PROJECT_ID = 'project1';
   const APP_ID = '1:23r:web:fewq';
@@ -80,6 +81,7 @@ describe('Performance Monitoring > remote_config_service', () => {
     settingsService.loggingEnabled = false;
     settingsService.networkRequestsSamplingRate = 1;
     settingsService.tracesSamplingRate = 1;
+    settingsService.logMaxFlushSize = 40;
   }
 
   // parameterized beforeEach. Should be called at beginning of each test.
@@ -150,6 +152,7 @@ describe('Performance Monitoring > remote_config_service', () => {
       expect(SettingsService.getInstance().tracesSamplingRate).to.equal(
         TRACE_SAMPLING_RATE
       );
+      expect(SettingsService.getInstance().logMaxFlushSize).to.equal(10);
     });
 
     it('does not call remote config if a valid config is in local storage', async () => {
@@ -190,6 +193,7 @@ describe('Performance Monitoring > remote_config_service', () => {
       expect(SettingsService.getInstance().tracesSamplingRate).to.equal(
         TRACE_SAMPLING_RATE
       );
+      expect(SettingsService.getInstance().logMaxFlushSize).to.equal(10);
     });
 
     it('does not change the default config if call to RC fails', async () => {
@@ -207,6 +211,7 @@ describe('Performance Monitoring > remote_config_service', () => {
       await getConfig(performanceController, IID);
 
       expect(SettingsService.getInstance().loggingEnabled).to.equal(false);
+      expect(SettingsService.getInstance().logMaxFlushSize).to.equal(40);
     });
 
     it('uses secondary configs if the response does not have all the fields', async () => {

packages/performance/src/services/remote_config_service.ts

@@ -38,6 +38,7 @@ interface SecondaryConfig {
   transportKey?: string;
   tracesSamplingRate?: number;
   networkRequestsSamplingRate?: number;
+  logMaxFlushSize?: number;
 }
 
 // These values will be used if the remote config object is successfully
@@ -56,6 +57,7 @@ interface RemoteConfigTemplate {
   fpr_vc_network_request_sampling_rate?: string;
   fpr_vc_trace_sampling_rate?: string;
   fpr_vc_session_sampling_rate?: string;
+  fpr_log_max_flush_size?: string;
 }
 /* eslint-enable camelcase */
 
@@ -221,6 +223,14 @@ function processConfig(
     settingsServiceInstance.tracesSamplingRate =
       DEFAULT_CONFIGS.tracesSamplingRate;
   }
+
+  if (entries.fpr_log_max_flush_size) {
+    settingsServiceInstance.logMaxFlushSize = Number(
+      entries.fpr_log_max_flush_size
+    );
+  } else if (DEFAULT_CONFIGS.logMaxFlushSize) {
+    settingsServiceInstance.logMaxFlushSize = DEFAULT_CONFIGS.logMaxFlushSize;
+  }
   // Set the per session trace and network logging flags.
   settingsServiceInstance.logTraceAfterSampling = shouldLogAfterSampling(
     settingsServiceInstance.tracesSamplingRate

packages/performance/src/services/settings_service.ts

@@ -54,6 +54,10 @@ export class SettingsService {
   // TTL of config retrieved from remote config in hours.
   configTimeToLive = 12;
 
+  // The max number of events to send during a flush. This number is kept low to since Chrome has a
+  // shared payload limit for all sendBeacon calls in the same nav context.
+  logMaxFlushSize = 40;
+
   getFlTransportFullUrl(): string {
     return this.flTransportEndpointUrl.concat('?key=', this.transportKey);
   }

packages/performance/src/services/transport_service.ts

@@ -26,9 +26,6 @@ const DEFAULT_REMAINING_TRIES = 3;
 
 // Most browsers have a max payload of 64KB for sendbeacon/keep alive payload.
 const MAX_SEND_BEACON_PAYLOAD_SIZE = 65536;
-// The max number of events to send during a flush. This number is kept low to since Chrome has a
-// shared payload limit for all sendBeacon calls in the same nav context.
-const MAX_FLUSH_SIZE = 40;
 
 const TEXT_ENCODER = new TextEncoder();
 
@@ -189,7 +186,7 @@ export function flushQueuedEvents(): void {
 
   while (queue.length > 0) {
     // Send the last events first to prioritize page load traces
-    const staged = queue.splice(-MAX_FLUSH_SIZE);
+    const staged = queue.splice(-SettingsService.getInstance().logMaxFlushSize);
     const body = buildPayload(staged);
 
     if (