From 59ac762c9029817c86e391fc3b71976673d54ef9 Mon Sep 17 00:00:00 2001
From: ayasayadi1 <aya.sayadi@count.ly>
Date: Thu, 26 Oct 2023 11:40:50 +0000
Subject: [PATCH] recreate cursor when closed

---
 bin/scripts/fix-data/recheck_merges.js | 58 +++++++++++---------------
 1 file changed, 24 insertions(+), 34 deletions(-)

diff --git a/bin/scripts/fix-data/recheck_merges.js b/bin/scripts/fix-data/recheck_merges.js
index 683d77058b4..ace60b0d00d 100755
--- a/bin/scripts/fix-data/recheck_merges.js
+++ b/bin/scripts/fix-data/recheck_merges.js
@@ -35,39 +35,27 @@ Promise.all([pluginManager.dbConnection("countly"), pluginManager.dbConnection("
                 console.log("Processing app: ", app.name);
                 //get all drill collections for this app
                 var collections = await getDrillCollections(app._id);
-                //start session
-                const session = await countlyDb.client.startSession();
-                //create batch cursor
-                var batchRemaining = true;
-                var batchStart = 0;
-                var batchSize = 100;
-                const usersCollection = session.client.db("countly").collection('app_users' + app._id);
-                //while there are users left
-                while (batchRemaining) {
-                    var usersCursor = usersCollection.find({merges: {$gt: 0}}, {_id: 1, uid: 1, merged_uid: 1}).skip(batchStart).limit(batchSize).addCursorFlag('noCursorTimeout', true);
-                    var refreshTimestamp = new Date();
-                    if (!await usersCursor.hasNext()) {
-                        batchRemaining = false;
+                //cursor
+                const usersCollection = countlyDb.collection('app_users' + app._id);
+                var usersCursor = usersCollection.find({merges: {$gt: 0}}, {_id: 1, uid: 1, merged_uid: 1});
+                //processed users count
+                var processedUsersCount = 0;
+                //for each user
+                while (usersCursor && await usersCursor.hasNext()) {
+                    //increment processed users count
+                    processedUsersCount++;
+                    //get next user
+                    const user = await usersCursor.next();
+                    //check if old uid still exists in drill collections
+                    if (user && user.merged_uid) {
+                        await processUser(user.merged_uid, user.uid, collections, app);
                     }
-                    else {
-                        //increment batch start
-                        batchStart += batchSize;
-                        //for each user
-                        while (await usersCursor.hasNext()) {
-                            if ((new Date() - refreshTimestamp) / 1000 > 0.001) {
-                                console.log("Refreshing session");
-                                await session.client.db("countly").admin().command({ refreshSessions: [session.id] });
-                                refreshTimestamp = new Date();
-                            }
-                            const user = await usersCursor.next();
-                            //check if old uid still exists in drill collections
-                            if (user && user.merged_uid) {
-                                await processUser(user.merged_uid, user.uid, collections, app);
-                            }
-                        }
+                    //if cursor is closed, recreate it and skip processed users
+                    if (!usersCursor) {
+                        usersCursor = usersCollection.find({merges: {$gt: 0}}, {_id: 1, uid: 1, merged_uid: 1}).skip(processedUsersCount);
                     }
                 }
-                session.endSession();
+
             }, function(err) {
                 return close(err);
             });
@@ -145,11 +133,13 @@ Promise.all([pluginManager.dbConnection("countly"), pluginManager.dbConnection("
     }
 
     function close(err) {
-        if (err) {
-            console.log("Error: ", err);
-        }
         countlyDb.close();
         drillDb.close();
-        console.log("Done.");
+        if (err) {
+            console.log("Finished with errors: ", err);
+        }
+        else {
+            console.log("Finished successfully.");
+        }
     }
 });
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