Oct 5, 2010

Planned Outage: October 10

On October 10th at 1am ET (see this in your timezone), we’re performing major infrastructure upgrades to MailChimp. We anticipate this planned outage will take between 2 and 4 hours to perform.

Details about the upgrade:

We’re moving a large portion of MailChimp’s brain power to a much bigger, much faster server. Our recent growth, and the rapid uptake of Social Pro (there were more than 50 million social data queries since we made it free 2 weeks ago in v5.3), mean we have to add extra capacity much sooner than anticipated.

Holiday Preparation

And looking forward at the upcoming holiday season, we’re forecasting email volume to ramp up significantly. We’re delivering around 25 million emails per day right now, but the number of customers signing up for MailChimp is increasing at an alarming(ly awesome) rate. We very well may be delivering up to one billion emails per month by the end of the year, though email traffic does die off significantly mid-December. Anyway, we want to perform this upgrade well before things kick in for the holidays.

MailChimp services will be unavailable during the upgrade

Most of our upgrades are like changing tires on a moving car: we rarely pull over to stop, because your emails, your open tracking, and your list subscriptions never stop. But this upgrade is more like swapping out our engine (and adding in 4 turbochargers, plus a larger trunk), so we have to stop the car this time. That means open tracking, click tracking, list subscriptions, and everything will be temporarily turned off.

Any MailChimp campaigns that are scheduled to deliver during the time of the upgrade window will be picked back up and sent after the upgrade is complete.

We will do our absolute best to perform this operation as fast as humanly possible.