"MongoError: No such cmd: createIndexes" using OpenShift - node.js

Question

I'm creating a node.js app that sends reminders using agenda.js. It works perfectly when I test it locally, but when I test it on OpenShift, I get the following error message:
MongoError: No such cmd: createIndexes
I only get this error when the information for a new reminder is sent to the server, i.e. only when agenda.js is used.
I've looked up createIndexes, and it seems that it was implemented in version 2.6 of MongoDB, and OpenShift currently only appears to support version 2.4.
My question is, is there a way around this? Perhaps a way to manually upgrade to the latest version of MongoDB, or not to use a cartridge at all (not sure what that actually is)?

Answer 1

Before 2.6, there wasn't an internal command called CreateIndexes. It was necessary to insert and object on the system.indexes collection directly.
On mongo shell, there were 2 helpers for that, with different names:
db.collection.createIndex, which still exists nowadays;
db.collection.ensureIndex, which was removed from 2.6 on.
I couldn't understand what exactly is issuing the create index command. Is it your SDK? Because it is supposed to be done just once, and not on every insert.

Answer 2

I had the same issue, and, as a workaround, used Agenda 0.6.28 instead (as it worked in a previous project of mine under that version).
Mind that Agenda does not emit a 'ready' event in this lower version, so you'd better call the 'start' function directly:
agenda.define('delete old session logs', jobs.cleanSessionLogs);
agenda.on('fail', function(err, job) {
errorLog.error({ err: err, job: job });
});
agenda.every('1 hour', 'delete old session logs');
agenda.start();
instead of:
agenda.define('delete old session logs', jobs.cleanSessionLogs);
agenda.on('fail', function(err, job) {
errorLog.error({ err: err, job: job });
});
agenda.on('ready', function() {
agenda.every('1 hour', 'delete old session logs');
agenda.start();
});