These errors happen thousands of times per day on a given swift proxy server:
Jun 18 06:28:15 ms-fe1005 proxy-server: ERROR with Object server 10.64.32.223:6000/sdf1 re: Trying to GET /v1/AUTH_mw/wikipedia-commons-local-thumb.f4/f/f4/Flickr_-_%E2%80%A6trialsanderrors_-_Marion_Davies%2C_Ziegfeld_girl%2C_by_Alfred_Cheney_Johnston%2C_1924.jpg/800px-Flickr_-_%E2%80%A6trialsanderrors_-_Marion_Davies%2C_Ziegfeld_girl%2C_by_Alfred_Cheney_Johnston%2C_1924.jpg: ConnectionTimeout (0.5s) (txn: tx5facf4161a494da2b2556-005d08847f) (client_ip: x.x.x.x)
They result in 503s experienced by users.
It appears that different swift object servers (probably all) enter a state where they have hanging connections like this for a short time, resulting in small bursts of such errors.
We could increase the timeout at the swift proxy level to see if helps, but it would be good to figure out what's causing swift object servers to behave like this.