[Moin-user] Multi-location moinmoin implementation?

[Thomas Waldmann]

Moin Philip,

I don't run such setups, but I hope this might be helpful nevertheless:

> We currently running our moinmoin wiki on an Amazon instance in North
> Virginia. We have people in China who are trying to access it and are
> reporting very poor access performance.

Can have many reasons.
Slow local internet connection at the user's site.
Slow regional network there.
High latency / slow international connection.
Even different system loads due to different typical usage hours.

> I'm thinking that one way of
> solving the problem would be to set up a second server in a location
> nearer to China, e.g. Tokyo or Singapore.

Sounds reasonable. But maybe ask some people in china if that really
helps / do comparative speed/latency tests.

> Off the top of my head, it would seem to be relatively straightforward
> to set up the Asia instance as read-only and then use rsync to
> replicate changes from the US instance to Asia.

Yes, that would work.

Do a maint cleancache and a moin process restart after rsyncing.

If you run exactly same python version, cpu architecture and maybe also
otherwise same-setup, you can maybe get away without cleancache.

> I could then use
> Amazon's geo technology to redirect users to the "nearest" server.

Maybe don't. Just have the servers at different URLs, so that people can
decide which one to use (read-only one for fast reading / searching, the
master for editing).

> 2. Ideally, both servers would be writeable and I'd be syncing in both
> directions but there is the risk of a collision then with two
> different people editing the same page at the same time. It would be a
> small risk, but the risk is there.

Right. Maybe the r/w master and r/o replica is simpler.

A third theoretical option is to set up a web proxy (squid, varnish,
...) near/inside china. But as wiki contents can change any time,
effectively caching them is non-trivial / not possible without risking
strange effects.

Cheers,

Thomas