This is a real troubleshooting example that I just did yesterday for a high CPU usage java application. The application uses tomcat and runs on AWS EC2. Login into the box, and change to root user so you can see all users' process. sudo su - Install htop if you have not installed it before, the run it. … Continue reading Troubleshoot high CPU usage java process
LuaXML_lib.so: wrong ELF class: ELFCLASS32
In a recent project, we use OpenResty (Scalable Web Platform by Extending NGINX with Lua) as API gateway. Nginx hosts the webserver, and Lua script stores the logic. One of our Lua files needs LuaXml modue to parse xml files. But the module is not installed by default in OpenResty. So we get this error … Continue reading LuaXML_lib.so: wrong ELF class: ELFCLASS32
Allow DELETE method pass payload in Akamai
We have a RESTful API endpoint for DELETE request sitting behind Akamai. And the DELETE request contains some data in the payload. By default, Akamai strips off the payload in DELETE method when you only turn on 'Allow DELETE'. To allow Akamai to pass the payload in DELETE method, you have to: Enable 'Allow All Methods on Parent Servers' on … Continue reading Allow DELETE method pass payload in Akamai
Nginx upstream key exchange issue
Continue with my previous post. Now it is about phase #3. Theoretically, it should be very straightward. All Nginx needs to do is just fowarding the Akamai reqeusts to the upstream. Right? But in real life, whatever can go wrong will go wrong 😦 In the testing, we always get '502 Bad Gateway' error. I … Continue reading Nginx upstream key exchange issue
Akamai protocol rewrite issue
I have been working on a API gateway project (Akamai + Nginx + Lua) for quite a few weeks. There are lots of things that I would like to write and share. This post is one of them. The high level architecture looks like this: Phases: Users send http(s) GET or POST requests to Akamai. Akamai … Continue reading Akamai protocol rewrite issue
