parse-server: MongoError: Transaction numbers are only allowed on storage engines that support document-level locking

I updated my parse server installation to version 3.8.0. I first got this error in the logs:

MongoError: This MongoDB deployment does not support retryable writes. Please add retryWrites=false to your connection string.

This was of course an easy fix and the error went away after adding the option to my connection string.

Now I see another error for queries to the database:

2019-08-27T07:44:31.538322+00:00 app[web.1]: MongoError: Transaction numbers are only allowed on storage engines that support document-level locking
2019-08-27T07:44:31.538354+00:00 app[web.1]: at Connection.<anonymous> (/app/node_modules/mongodb/lib/core/connection/pool.js:466:61)
2019-08-27T07:44:31.538359+00:00 app[web.1]: at emitTwo (events.js:126:13)
2019-08-27T07:44:31.538360+00:00 app[web.1]: at Connection.emit (events.js:214:7)
2019-08-27T07:44:31.538361+00:00 app[web.1]: at processMessage (/app/node_modules/mongodb/lib/core/connection/connection.js:364:10)
2019-08-27T07:44:31.538362+00:00 app[web.1]: at Socket.<anonymous> (/app/node_modules/mongodb/lib/core/connection/connection.js:533:15)
2019-08-27T07:44:31.538363+00:00 app[web.1]: at emitOne (events.js:116:13)
2019-08-27T07:44:31.538364+00:00 app[web.1]: at Socket.emit (events.js:211:7)
2019-08-27T07:44:31.538365+00:00 app[web.1]: at addChunk (_stream_readable.js:263:12)
2019-08-27T07:44:31.538369+00:00 app[web.1]: at readableAddChunk (_stream_readable.js:250:11)
2019-08-27T07:44:31.538370+00:00 app[web.1]: at Socket.Readable.push (_stream_readable.js:208:10)
2019-08-27T07:44:31.538371+00:00 app[web.1]: at TCP.onread (net.js:601:20)

I tried to find information on this issue myself and I think this is caused by my older MongoDB Server version. It currently runs 3.6.11 which does not support this feature.

I have not seen this issue on older releases of parse server. Any other config I need to change to make this work? Or is MongoDB 4 required for parse server now?

Server
- parse-server version: 3.8.0
- Operating System: heroku-18 stack
- Localhost or remote server? Heroku
Database
- MongoDB version: 3.6.11
- Localhost or remote server? mlab

About this issue

Original URL
State: closed
Created 5 years ago
Comments: 19 (14 by maintainers)

Commits related to this issue

added breaking change note to 3.8 release Breaking change as described here: https://github.com/parse-community/parse-server/issues/5983#issuecomment-527693465 — committed to mtrezza/parse-server by mtrezza 5 years ago
added breaking change note to 3.8 release (#6023) Breaking change as described here: https://github.com/parse-community/parse-server/issues/5983#issuecomment-527693465 — committed to parse-community/parse-server by mtrezza 5 years ago
added breaking change note to 3.8 release (#6023) Breaking change as described here: https://github.com/parse-community/parse-server/issues/5983#issuecomment-527693465 — committed to UnderratedDev/parse-server by mtrezza 5 years ago
add retrywrites=false to please mLab mongodb. https://github.com/parse-community/parse-server/issues/5983 — committed to SebastianAigner/vollstapel by SebastianAigner 4 years ago

Most upvoted comments

+1 I had this error until I added retryWrites=false to my database uri.

+15

omairvaiyani on Sep 3, 2019

I feel very bad right now because I made an obvious mistake!

I appended ?retryWrites=false to the URI. However this is wrong as there is already the replicaSet parameter and therefore I need to append &retryWrites=false to make it work correctly.

So this is how it looks right now:

[...]?replicaSet=rs-ds00000?retryWrites=false

Working perfectly without any errors.

Thanks for all your help and patience.

funkenstrahlen on Sep 3, 2019

Don’t forget to quote the URL if setting this on Heroku. So do:

heroku config:set MONGODB_URI="mongodb://…&retryWrites=false"

with the double quotes. Otherwise the “&” will trip you up.

henrik on Nov 14, 2019

I’ve just taken a closer look in the MongoDB docs to understand the reasons. So let’s go:

In the last release of Parse Server, 3.8, we’ve upgraded our MongoDB driver to its latest version v3.3.0;
According to the MongoDB driver v3.3.0 release notes, it is now compatible with the MongoDB v4.2;
Looking at Retryable Writes documentation, it says that:

The official MongoDB 4.2-compatible drivers enable Retryable Writes by default. Applications upgrading to the 4.2-compatible drivers that require retryable writes may omit the retryWrites=true option. Applications upgrading to the 4.2-compatible drivers that require disabling retryable writes must include retryWrites=false in the connection string.

So, yes. If you are running your Parse Server on top of a MongoDB deployment which does not fit the Retryable Writes Requirements, you will have to add retryWrites=false to your connection string in order to upgrade to Parse Server 3.8.

@mtrezza I think it is worth to mention that in the release notes. Do you want to open a PR with this?

davimacedo on Sep 4, 2019

you could paste it here for us to dissect - take care to remove the hostname and authorisation details like so: mongodb://xx:xx@xx.com:33427,xx.com:33427/database-name?replicaSet=rs-xx&ssl=true&retryWrites=false

omairvaiyani on Sep 3, 2019