From c5562483aa611be8c6c6985ec1da80e9d1224b7e Mon Sep 17 00:00:00 2001
From: GCHQDeveloper36 <73173408+GCHQDeveloper36@users.noreply.github.com>
Date: Tue, 30 Apr 2024 21:26:42 +0000
Subject: [PATCH] Only use transactions on replica sets

---
 backend/src/services/model.ts | 26 ++++++++++++++++----------
 backend/src/utils/database.ts |  5 +++++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/backend/src/services/model.ts b/backend/src/services/model.ts
index 63fa1db74..f846bf20c 100644
--- a/backend/src/services/model.ts
+++ b/backend/src/services/model.ts
@@ -10,6 +10,7 @@ import ModelCardRevisionModel, { ModelCardRevisionDoc } from '../models/ModelCar
 import { UserInterface } from '../models/User.js'
 import { GetModelCardVersionOptions, GetModelCardVersionOptionsKeys, GetModelFiltersKeys } from '../types/enums.js'
 import { isValidatorResultError } from '../types/ValidatorResultError.js'
+import { isReplicaSet } from '../utils/database.js'
 import { toEntity } from '../utils/entity.js'
 import { BadReq, Forbidden, InternalError, NotFound } from '../utils/error.js'
 import { convertStringToId } from '../utils/id.js'
@@ -224,16 +225,21 @@ export async function _setModelCard(
 
   const revision = new ModelCardRevisionModel({ ...newDocument, modelId, createdBy: user.dn })
 
-  const message = 'Unable to save model card revision'
-  await mongoose.connection
-    .transaction(async function executeUpdate(session) {
-      await revision.save({ session })
-      await ModelModel.updateOne({ id: modelId }, { $set: { card: newDocument } }, { session: session })
-    })
-    .catch((error) => {
-      log.error('Error when updating model card/revision. Transaction rolled back.', error)
-      throw InternalError(message, { modelId })
-    })
+  if (await isReplicaSet()) {
+    await mongoose.connection
+      .transaction(async function executeUpdate(session) {
+        await revision.save({ session })
+        await ModelModel.updateOne({ id: modelId }, { $set: { card: newDocument } }, { session: session })
+      })
+      .catch((error) => {
+        const message = 'Unable to save model card revision'
+        log.error('Error when updating model card/revision. Transaction rolled back.', error)
+        throw InternalError(message, { modelId })
+      })
+  } else {
+    await revision.save()
+    await ModelModel.updateOne({ id: modelId }, { $set: { card: newDocument } })
+  }
 
   return revision
 }
diff --git a/backend/src/utils/database.ts b/backend/src/utils/database.ts
index aae04ddc6..45b0363ea 100644
--- a/backend/src/utils/database.ts
+++ b/backend/src/utils/database.ts
@@ -31,6 +31,11 @@ export async function connectToMongoose() {
   }
 }
 
+export async function isReplicaSet(): Promise<boolean> {
+  const options = mongoose.connection.getClient().options
+  return Object.prototype.hasOwnProperty.call(options, 'replicaSet') && options.replicaSet.length > 0
+}
+
 export async function disconnectFromMongoose() {
   await mongoose.disconnect()
   log.info({ log: false }, 'Disconnected from Mongoose')