Yes. My blog, and all my websites, have been delivering a lot of 503 error codes recently. When the error appears on my blog it also means that boomershoot.org, modernballistics.org, xeniajoy.com, scottfamilyplace.org and others are all doing the same.
When I last talked to tech support about this they said it was because I am getting more than 500 simultaneous connections. My logs from just the first four days of May show over 3000 “GET” requests for “wp-login.php” from nearly 1000 IP addresses. I read this as my blog is under attack.
I’m not convinced my logs are showing me everything.
I’ll investigate more this week.
Not necessarily an attack, it may just be anklebiters scanning for vulnerabilites.
I’ll second John’s comment. I’ve got a lot of those in my logs too, and I don’t even run the blog software they are targeting. I think there are botnets scanning for known vulnerabilities blindly.
Mind you, 500 simultaneous connections is a lot for blind scanning.
Have you considered using Cloudflare? In addition to caching files and improving performance, they also soak up potential attacks before they reach your site. Super easy to configure.