Redis CPU Usage Ramps Up after Kernel Patching


I guess you have heard the name of Meltdown and Spectre already. If not, check out this site https://meltdownattack.com/. Definitely, it is not a good start of a New Year. All Cloud providers are busy with patching the kernel of their underlying systems. AWS Elastic cache (Redis) is one of them. Due to its single threaded nature, … Continue reading Redis CPU Usage Ramps Up after Kernel Patching

Openssl error: SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol


If you see similar errors as below when using openssl to test a https site, it is most likely caused by the SNI that is configured in the reverse proxy or server, like Nginx. openssl s_client -connect bla.bla.com:443 CONNECTED(00000003) 51089:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:/BuildRoot/Library/Caches/com.apple.xbs/Sources/OpenSSL098/OpenSSL098-59.60.1/src/ssl/s23_clnt.c:618: To make it work, you need to specify the hostname in the command, … Continue reading Openssl error: SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol