From c05057f0aca227acf547ee2e3015dc2fa84e4401 Mon Sep 17 00:00:00 2001
From: Brian Gough <briangough@users.noreply.github.com>
Date: Tue, 15 Apr 2025 08:46:44 +0100
Subject: [PATCH] Merge pull request #24856 from
 overleaf/bg-history-redis-buffer-tweaks

fix error logging for chunk cache mismatches

GitOrigin-RevId: 85344c4025fdaa6ee916c5438ff38c7c49f4bce3
---
 .../history-v1/storage/lib/chunk_store/redis.js | 17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

diff --git a/services/history-v1/storage/lib/chunk_store/redis.js b/services/history-v1/storage/lib/chunk_store/redis.js
index 0dd146f89b..e13fa358f3 100644
--- a/services/history-v1/storage/lib/chunk_store/redis.js
+++ b/services/history-v1/storage/lib/chunk_store/redis.js
@@ -172,7 +172,22 @@ function compareChunks(projectId, cachedChunk, currentChunk) {
     return false
   }
   const identical = JSON.stringify(cachedChunk) === JSON.stringify(currentChunk)
-  logger.error({ projectId }, 'chunk cache mismatch')
+  if (!identical) {
+    try {
+      logger.error(
+        {
+          projectId,
+          cachedChunkStartVersion: cachedChunk.getStartVersion(),
+          cachedChunkEndVersion: cachedChunk.getEndVersion(),
+          currentChunkStartVersion: currentChunk.getStartVersion(),
+          currentChunkEndVersion: currentChunk.getEndVersion(),
+        },
+        'chunk cache mismatch'
+      )
+    } catch (err) {
+      // ignore errors while logging
+    }
+  }
   metrics.inc('chunk_store.redis.compare_chunks', 1, {
     status: identical ? 'success' : 'fail',
   })