From f82b407f305c149bc7a53457a5f77916c8db759a Mon Sep 17 00:00:00 2001
From: Andrew Kingston <andrew@kingston.dev>
Date: Mon, 25 Jul 2022 12:17:40 +0100
Subject: [PATCH] Ignore 409s in write-through cache

---
 packages/backend-core/src/cache/writethrough.ts | 7 +++----
 packages/backend-core/src/logging.ts            | 5 +++++
 2 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/packages/backend-core/src/cache/writethrough.ts b/packages/backend-core/src/cache/writethrough.ts
index e11ca0acaa..701351d75b 100644
--- a/packages/backend-core/src/cache/writethrough.ts
+++ b/packages/backend-core/src/cache/writethrough.ts
@@ -1,5 +1,6 @@
 import BaseCache from "./base"
 import { getWritethroughClient } from "../redis/init"
+import { logInfo } from "../logging"
 
 const DEFAULT_WRITE_RATE_MS = 10000
 let CACHE: BaseCache | null = null
@@ -51,10 +52,8 @@ export async function put(
       if (err.status !== 409) {
         throw err
       } else {
-        // get the rev, update over it - this is risky, may change in future
-        const readDoc = await db.get(doc._id)
-        doc._rev = readDoc._rev
-        await writeDb(doc)
+        // Swallow 409s but log them
+        logInfo(`Ignoring conflict in write-through cache`)
       }
     }
   }
diff --git a/packages/backend-core/src/logging.ts b/packages/backend-core/src/logging.ts
index 68c3307b2f..fcfa04bbb9 100644
--- a/packages/backend-core/src/logging.ts
+++ b/packages/backend-core/src/logging.ts
@@ -15,6 +15,11 @@ export function logAlert(message: string, e?: any) {
   console.error(`bb-alert: ${message} ${errorJson}`)
 }
 
+export function logInfo(message: string) {
+  console.warn(`bb-info: ${message}`)
+}
+
 export default {
   logAlert,
+  logInfo,
 }