[MongoDB Storage] Increase timeouts for checksums from 40s -> 80s (#338)

* Increase timeouts for checksums from 40s -> 80s.

* Changeset.

Author: rkistner

.changeset/silver-keys-confess.md

@@ -0,0 +1,8 @@
+---
+'@powersync/service-module-mongodb-storage': patch
+'@powersync/lib-service-mongodb': patch
+'@powersync/service-core': patch
+'@powersync/service-image': patch
+---
+
+[MongoDB Storage] Increase checksum timeouts

libs/lib-mongodb/src/db/mongo.ts

@@ -9,8 +9,11 @@ export const MONGO_CONNECT_TIMEOUT_MS = 10_000;
 
 /**
  * Time for individual requests to timeout the socket.
+ *
+ * Currently increased to cater for slow checksum calculations - may be reduced to 60s again
+ * if we optimize those.
  */
-export const MONGO_SOCKET_TIMEOUT_MS = 60_000;
+export const MONGO_SOCKET_TIMEOUT_MS = 90_000;
 
 /**
  * Time for individual requests to timeout the operation.
@@ -21,6 +24,18 @@ export const MONGO_SOCKET_TIMEOUT_MS = 60_000;
  */
 export const MONGO_OPERATION_TIMEOUT_MS = 40_000;
 
+/**
+ * Time for individual checksums requests to timeout the operation.
+ *
+ * This is time spent on the cursor, not total time.
+ *
+ * Must be less than MONGO_SOCKET_TIMEOUT_MS to ensure proper error handling.
+ *
+ * This is temporarily increased to cater for slow checksum calculations,
+ * may be reduced to MONGO_OPERATION_TIMEOUT_MS again if we optimize those.
+ */
+export const MONGO_CHECKSUM_TIMEOUT_MS = 80_000;
+
 /**
  * Same as above, but specifically for clear operations.
  *

modules/module-mongodb-storage/src/storage/implementation/MongoSyncBucketStorage.ts

@@ -537,7 +537,7 @@ export class MongoSyncBucketStorage
             }
           }
         ],
-        { session: undefined, readConcern: 'snapshot', maxTimeMS: lib_mongo.db.MONGO_OPERATION_TIMEOUT_MS }
+        { session: undefined, readConcern: 'snapshot', maxTimeMS: lib_mongo.db.MONGO_CHECKSUM_TIMEOUT_MS }
       )
       .toArray()
       .catch((e) => {