Skype is still recovering from its massive outage yesterday, but it is getting back to normal. Instant messages still seem to have a delay (anecdotally, I am noticing that I hear the IM ping, but then it is hit or miss whether any message comes through), but voice calls are working fine. I know because I just spoke with CEO Tony Bates over Skype. He estimates that between 16 million and 17 million Skype users, or about 80 percent of the people who would be on the service right now, can use it. “We are bringing folks back on in a controlled manner,” he says.
Bates priority is to get the service back up and running and to make sure Skype does not lose the trust of its users. To rectify that, he is publicly apologizing to them for the downtime and will offer users some sort of credits, with more details on that coming out later today. (Yes, free calls!) This is the right approach, and reminds me of what Netflix does when its streaming movie service goes down (free movies). Although credits may only go to paying customers wh already have SkypeOut accounts.
The ultimate cause of the outage is still unclear (or at least Skype isn’t ready to talk about it yet). When I asked if Skype has ruled out a malicious attack, Bates responded: “We haven’t ruled anything out.” Here is what we do know. Many Skype clients on the open Internet act as “supernodes.” These are directories which act like a big peer-to-peer telephone book helping one Skype client find another. These supernodes somehow were overloaded and went down.
Skype had to put up new supernodes to make up for the outage, and did so by redeploying the servers normally used for group video and offline IM features. Those features are down right now. Pulling the servers from other Skype services seems like a short-term solution until Skype can figure out something longer term.
Whatever the ultimate cause, the incident shows up the weak spot in Skype’s network. Take down the supernodes and the whole service goes with them.
Update: Below is a video message from CEO Bates to users about the outage and what Skype is doing about it:
Update 2: Skype has another update. Now they say the cause wasn’t malicious attack, and they are going to give 30 free minutes of calls to landline phones to paying customers. From their latest blog post:
We now understand the cause of the problem and we believe it was not caused by a malicious attack. But, we are still doing a full analysis and we will provide an in-depth post-mortem.
Nothing can make up for the missed experiences, but we’re going to be sending our Pay As You Go and Pre-Pay users a Skype Credit voucher via email. The voucher can be used to give you approximately 30 minutes of free calling to landlines anywhere in the world.*
For our active subscribers, we will credit you with a week’s extra subscription service