[dashboard] Improve RTT measurement

Author: csweichel

components/dashboard/src/Login.tsx

@@ -22,7 +22,6 @@ import fresh from "./images/welcome/fresh.svg";
 import prebuild from "./images/welcome/prebuild.svg";
 import exclamation from "./images/exclamation.svg";
 import { getURLHash } from "./App";
-import { measureAndPickWorkspaceClusterRegion } from "./start/choose-region";
 
 
 function Item(props: { icon: string, iconSize?: string, text: string }) {
@@ -85,8 +84,6 @@ export function Login() {
     const authorizeSuccessful = async (payload?: string) => {
         updateUser().catch(console.error);
 
-        await measureAndPickWorkspaceClusterRegion();
-
         // Check for a valid returnTo in payload
         const safeReturnTo = getSafeURLRedirect(payload);
         if (safeReturnTo) {

components/dashboard/src/start/CreateWorkspace.tsx

@@ -17,6 +17,7 @@ import { openAuthorizeWindow } from "../provider-utils";
 import { SelectAccountPayload } from "@gitpod/gitpod-protocol/lib/auth";
 import { SelectAccountModal } from "../settings/SelectAccountModal";
 import { watchHeadlessLogs } from "../components/PrebuildLogs";
+import { measureAndPickWorkspaceClusterRegion } from "./choose-region";
 
 const WorkspaceLogs = React.lazy(() => import('../components/WorkspaceLogs'));
 
@@ -46,6 +47,9 @@ export default class CreateWorkspace extends React.Component<CreateWorkspaceProp
     // Invalidate any previous result.
     this.setState({ result: undefined, stillParsing: true });
 
+    // Ensure we'll land on a good workspace custer
+    await measureAndPickWorkspaceClusterRegion();
+
     // We assume anything longer than 3 seconds is no longer just parsing the context URL (i.e. it's now creating a workspace).
     let timeout = setTimeout(() => this.setState({ stillParsing: false }), 3000);
 

components/dashboard/src/start/StartPage.tsx

@@ -6,7 +6,6 @@
 
 import { useEffect } from 'react';
 import gitpodIcon from '../icons/gitpod.svg';
-import { measureAndPickWorkspaceClusterRegion } from './choose-region';
 
 export enum StartPhase {
   Checking = 0,
@@ -85,7 +84,6 @@ export function StartPage(props: StartPageProps) {
   const { phase, error } = props;
   let title = props.title || getPhaseTitle(phase, error);
   useEffect(() => { document.title = 'Starting — Gitpod' }, []);
-  measureAndPickWorkspaceClusterRegion();
   return <div className="w-screen h-screen align-middle">
     <div className="flex flex-col mx-auto items-center text-center h-screen">
       <div className="h-1/3"></div>

components/dashboard/src/start/StartWorkspace.tsx

@@ -15,6 +15,7 @@ import PendingChangesDropdown from "../components/PendingChangesDropdown";
 import { watchHeadlessLogs } from "../components/PrebuildLogs";
 import { getGitpodService, gitpodHostUrl } from "../service/service";
 import { StartPage, StartPhase, StartWorkspaceError } from "./StartPage";
+import { measureAndPickWorkspaceClusterRegion } from "./choose-region";
 const sessionId = v4();
 
 const WorkspaceLogs = React.lazy(() => import('../components/WorkspaceLogs'));
@@ -117,6 +118,9 @@ export default class StartWorkspace extends React.Component<StartWorkspaceProps,
       }
     }
 
+    // Ensure we'll land on a good workspace custer - this call will take max 1 second
+    await measureAndPickWorkspaceClusterRegion();
+
     const { workspaceId } = this.props;
     try {
       const result = await getGitpodService().server.startWorkspace(workspaceId, { forceDefaultImage });

components/dashboard/src/start/choose-region.ts

@@ -14,49 +14,45 @@ import { getGitpodService } from "../service/service";
  * @returns void
  */
 async function measureAndPickWorkspaceClusterRegion(): Promise<void> {
-    const eps = await getGitpodService().server.listWorkspaceClusterRTTEndpoints();
+    const localStorageKey = "measureAndPickWorkspaceClusterRegion.lastMeasurement";
 
-    if (!!eps.lastMeasurement) {
-        const lrm = Date.parse(eps.lastMeasurement);
-        if (Date.now() - lrm < 6*60*60*1000) {
-            // we checked within the last six hours. Nothing to do here.
+    let lastCheck = localStorage.getItem(localStorageKey);
+    try {
+        if (!lastCheck || (Date.now() - Date.parse(lastCheck)) < 6*60*60*1000) {
+            // we've recently done the check.
             return;
         }
+    } catch (err) {
+        // Date.parse can fail ... in which case we assume we haven't done the RTT measurement recently.
     }
 
+    const eps = await getGitpodService().server.listWorkspaceClusterRTTEndpoints();
+
     const region = await Promise.race(eps.candidates.map(ep => measureRTT(ep.endpoint, ep.region)));
     if (!region) {
         console.warn("did not find a prefered workspace cluster region");
         return;
     }
 
+    localStorage.setItem(localStorageKey, new Date().toISOString())
     await getGitpodService().server.setWorkspaceClusterPreferences({ region });
 }
 
 async function measureRTT(endpoint: string, region: string): Promise<string | undefined> {
-    const laps = 5;
-    let count = 0;
-    for (let i = 0; i < laps; i++) {
-        const controller = new AbortController();
-        const abort = setTimeout(() => controller.abort(), 1000);
-
-        try {
-            await fetch(endpoint, {
-                cache: "no-cache",
-                signal: controller.signal,
-            });
-            count++;
-        } catch (err) {
-            console.debug(`failed to fetch RTT endpoint ${endpoint}: ${err}`);
-        } finally {
-            clearTimeout(abort);
-        }
-    }
-
-    if (count < 5) {
-        // we haven't completed all RTT measurements, hence take a penalty lap.
-        await new Promise(resolve => setTimeout(resolve, laps * 1000));
-        return;
+    const controller = new AbortController();
+    const abort = setTimeout(() => controller.abort(), 1000);
+
+    try {
+        await Promise.all(Array(5).map(async () => {
+            try {
+                await fetch(endpoint, { cache: "no-cache", signal: controller.signal, });
+            } catch (err) {
+                // we don't want a single error to abort the race. For example, it's ok
+                // if the RTT endpoints return 404.
+            }
+        }))
+    } finally {
+        clearTimeout(abort);
     }
 
     return region;

components/gitpod-protocol/src/protocol.ts

@@ -1254,13 +1254,9 @@ export interface Terms {
 
 export interface WorkspaceClusterPreference {
     region?: string;
-    // lrm == lastRegionMeasurement. Not writing the full name to save
-    // a few 100mb in the database.
-    lrm?: string;
 }
 
 export interface WorkspaceClusterRTTEndpoints {
-    lastMeasurement?: string;
     candidates: {
         region: string;
         endpoint: string;

components/server/src/workspace/gitpod-server-impl.ts

@@ -2196,7 +2196,6 @@ export class GitpodServerImpl implements GitpodServerWithTracing, Disposable {
         });
 
         return {
-            lastMeasurement: user.additionalData?.clusterPreferences?.lrm,
             candidates: [...new Set(allEndpoints)]
         };
     }
@@ -2209,7 +2208,6 @@ export class GitpodServerImpl implements GitpodServerWithTracing, Disposable {
 
         // don't just dump `pref` in here, we have no idea what it contains.
         clusterPref.region = pref.region;
-        clusterPref.lrm = new Date().toISOString();
 
         data.clusterPreferences = clusterPref;
         user.additionalData = data;