Last week we migrated the Qt project forums to NodeBB.
All the feedback has been really positive.

The new Qt Forums at: http://forum.qt.io

I don't think ours is the biggest, but this needs to have some starting point.

Qt Forum http://forum.qt.io
21 000 users
270 000 posts in 54 000 topics

My guess is that gaming some forum dwarfs that by on order of magnitude.

@Codejet good approach.
And thanks for the info.

I'll move us back to 0.6.1 from 0.6.x. It isn't a big operation, we anyway need to run a full import into a clean database when we do the final move.

The experience with NodeBB has been really good.

@ludam the answer is both. Search for clustering here on the forums.

We are running a big community site with NodeBB (close to 25000 members but a lot less posts, only some hundred thousands). Both Redis and Mongo set up so we can cluster the system. Initially we tried to set up just redis on a small test machine, but got no human perceivable performance difference to the clustered set-up.

Works beautifully and is way faster than what we had previously.