fix(redis): treat ignorable Redis errors as warnings

common/changes/@microsoft/rush/sennyeya-fix-redis-error_2025-08-26-23-37.json

@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "comment": "Treat intermittent ignored redis errors as warnings and allow build to continue.",
+      "type": "none",
+      "packageName": "@microsoft/rush"
+    }
+  ],
+  "packageName": "@microsoft/rush",
+  "email": "aramissennyeydd@users.noreply.github.com"
+}

common/config/subspaces/default/repo-state.json

@@ -1,5 +1,5 @@
 // DO NOT MODIFY THIS FILE MANUALLY BUT DO COMMIT IT. It is generated and used by Rush.
 {
-  "pnpmShrinkwrapHash": "c643d2cc7e2c60ef034a6557fc89760140d42f66",
+  "pnpmShrinkwrapHash": "e0b573b05fff66c7c9e7ae104e8a2f863ef58864",
   "preferredVersionsHash": "61cd419c533464b580f653eb5f5a7e27fe7055ca"
 }

rush-plugins/rush-redis-cobuild-plugin/package.json

@@ -19,7 +19,7 @@
     "_phase:test": "heft run --only test -- --clean"
   },
   "dependencies": {
-    "@redis/client": "~1.5.5",
+    "@redis/client": "~5.8.2",
     "@rushstack/node-core-library": "workspace:*",
     "@rushstack/rush-sdk": "workspace:*"
   },

rush-plugins/rush-redis-cobuild-plugin/src/RedisCobuildLockProvider.ts

@@ -46,10 +46,18 @@ export class RedisCobuildLockProvider implements ICobuildLockProvider {
     string
   >();
 
-  private readonly _redisClient: RedisClientType<RedisModules, RedisFunctions, RedisScripts>;
+  private readonly _redisClient: RedisClientType<RedisModules, RedisFunctions, RedisScripts, 2 | 3>;
 
   public constructor(options: IRedisCobuildLockProviderOptions, rushSession: RushSession) {
     this._options = RedisCobuildLockProvider.expandOptionsWithEnvironmentVariables(options);
+    // Provide a default reconnect strategy that prevents more than 5 reconnect attempts.
+    this._options.socket = {
+      reconnectStrategy: (count: number) => {
+        this._terminal.writeErrorLine(`Redis client reconnecting attempt #${count}`);
+        return count < 5 ? count * 1000 : false;
+      },
+      ...this._options.socket
+    };
     this._terminal = rushSession.getLogger('RedisCobuildLockProvider').terminal;
     try {
       this._redisClient = createClient(this._options);
@@ -95,11 +103,20 @@ export class RedisCobuildLockProvider implements ICobuildLockProvider {
     } catch (e) {
       throw new Error(`Failed to connect to redis server: ${e.message}`);
     }
+
+    // Register error event handler to avoid process exit when redis client error occurs.
+    this._redisClient.on('error', (e: Error) => {
+      if (e.message) {
+        this._terminal.writeErrorLine(`Redis client error: ${e.message}`);
+      } else {
+        this._terminal.writeErrorLine(`Redis client error: ${e}`);
+      }
+    });
   }
 
   public async disconnectAsync(): Promise<void> {
     try {
-      await this._redisClient.disconnect();
+      await this._redisClient.destroy();
     } catch (e) {
       throw new Error(`Failed to disconnect to redis server: ${e.message}`);
     }

rush-plugins/rush-redis-cobuild-plugin/src/test/RedisCobuildLockProvider.test.ts

@@ -58,7 +58,12 @@ describe(RedisCobuildLockProvider.name, () => {
         get: jest.fn().mockImplementation((key: string) => {
           return storage[key];
         })
-      } as unknown as RedisClientType;
+      } as unknown as RedisClientType<
+        redisAPI.RedisModules,
+        redisAPI.RedisFunctions,
+        redisAPI.RedisScripts,
+        2 | 3
+      >;
     });
   });