From 33975575b28f091a4e65f36904491080a08f6bc5 Mon Sep 17 00:00:00 2001
From: masnwilliams <43387599+masnwilliams@users.noreply.github.com>
Date: Mon, 13 Jul 2026 20:27:19 +0000
Subject: [PATCH] Add timeouts and bounded reconnect to Redis client

Previously the Redis client retried reconnecting forever with no connect or
command timeout, so an unreachable Redis made callers (e.g. the OAuth token
exchange) block indefinitely instead of failing. Bound the reconnect attempts,
set a connect timeout, and cap each command so Redis outages surface as errors.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
---
 src/lib/redis.ts | 43 ++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 38 insertions(+), 5 deletions(-)

diff --git a/src/lib/redis.ts b/src/lib/redis.ts
index 3c81182..b0c6a98 100644
--- a/src/lib/redis.ts
+++ b/src/lib/redis.ts
@@ -9,9 +9,22 @@ if (redisTlsServerName && parsedRedisUrl?.protocol !== "rediss:") {
   throw new Error("REDIS_TLS_SERVER_NAME requires REDIS_URL to use rediss://");
 }
 
-// Modest backoff to smooth over first-hit cold connections
-const reconnectStrategy = (retries: number) =>
-  Math.min(500 + retries * 100, 2000);
+// Upper bound on connecting and on any single command, so an unreachable Redis
+// surfaces as an error instead of blocking the caller (e.g. OAuth token exchange).
+const CONNECT_TIMEOUT_MS = 5000;
+const COMMAND_TIMEOUT_MS = 5000;
+
+// Modest backoff to smooth over first-hit cold connections, but give up after a
+// bounded number of attempts rather than retrying forever while Redis is down.
+const MAX_RECONNECT_ATTEMPTS = 10;
+const reconnectStrategy = (retries: number) => {
+  if (retries > MAX_RECONNECT_ATTEMPTS) {
+    return new Error(
+      `Redis unavailable after ${MAX_RECONNECT_ATTEMPTS} reconnect attempts`,
+    );
+  }
+  return Math.min(500 + retries * 100, 2000);
+};
 
 // Connect on first use
 let isConnected = false;
@@ -24,9 +37,11 @@ const client = createClient({
         host: parsedRedisUrl!.hostname,
         tls: true,
         servername: redisTlsServerName,
+        connectTimeout: CONNECT_TIMEOUT_MS,
         reconnectStrategy,
       }
     : {
+        connectTimeout: CONNECT_TIMEOUT_MS,
         reconnectStrategy,
       },
 });
@@ -179,14 +194,32 @@ function isTransientSocketError(error: unknown): boolean {
   );
 }
 
+async function withTimeout<T>(operation: () => Promise<T>): Promise<T> {
+  let timer: ReturnType<typeof setTimeout> | undefined;
+  const timeout = new Promise<never>((_, reject) => {
+    timer = setTimeout(
+      () =>
+        reject(
+          new Error(`Redis command timed out after ${COMMAND_TIMEOUT_MS}ms`),
+        ),
+      COMMAND_TIMEOUT_MS,
+    );
+  });
+  try {
+    return await Promise.race([operation(), timeout]);
+  } finally {
+    if (timer) clearTimeout(timer);
+  }
+}
+
 async function withReconnect<T>(operation: () => Promise<T>): Promise<T> {
   try {
-    return await operation();
+    return await withTimeout(operation);
   } catch (err) {
     if (isTransientSocketError(err)) {
       isConnected = false;
       await ensureConnected();
-      return await operation();
+      return await withTimeout(operation);
     }
     throw err;
   }