After a 6 months break I’m back to blogging. I hope that my motivation will stay as high as it was when I was starting with it. My absence was caused by the operation of moving to Berlin, what was pretty occupying*. Now, when the moving is finally done, I can go back on the trail :)
*After 2 months I still don’t have stable internet connection at home. Don’t ask me why.
This blog post will be the first part of the bigger proof of concept related to the data replication in distributed environment, which I’m working on. At the beginning, I will show how to separate GET requests from POST having multiple instances of a single application. The goal is to redirect all of the POST requests to the master instance, all GET requests should be distributed across all nodes. Today’s showcase will be focused on three subjects: single master - multiple slaves communication model, leader election between multiple application nodes, and using Service Discovery for automatic load balancer configuration. In this part we’re finding out how to simply use ZooKeeper for Service Discovery and Leader Election, NGINX as a load balancer with dynamically changing configuration by confd. NGINX is a web server, which can act as reverse proxy, load balancer or HTTP cache. In our case NGINX will be responsible for traffic load balancing to the appropriate nodes.
Sometimes while attending a Java conference or reading some article on the internet, you can find out that many people think that Java EE is dead. It comes mostly from people strongly addicted to Spring Framework and its many cool features. They believe that Java EE is so 90’ and Spring is the only right solution. I don’t deny that Spring Framework is a great tool. Java EE is just the same tool which resolves the same problems, so we should have an open mind. One of these cool features of Spring is the ease to use a high level database abstraction called Spring Data JPA.
Your motivation is close to 0. You’re a part of IT division that is thought to be just a cost, not an income. Everyone’s quitting. There is a feeling that you’re not learning or growing anymore. It’s not fun anymore. Bad decisions are being made.
Just ask your partner, friend or your parent if you should change your job. They may know what is best for you because they spend so much time with you. Some impressions are not visible for you yourself.
Last week I had a chance to be for the third time at a Java conference called GeeCON. I really enjoyed this event because of the number of great people and many interesting topics related to the JVM world. By visiting such conferences you can learn new things and get to know the expert’s newest opinions. However, after this event, as always, I have more questions than answers. Some mysterious magic was present there and, as software developer, I feel the need to make this magic disappear. So I have to spend some time reading articles, doing research and experimenting. In this post I want to summarize the best presentations I’ve been by those 3 days in Cracow.
If we are creating application for some client or for ourselves we need at some point to deploy our work on production servers and expose to the world. For most cases it’s obvious that our application cannot work as one instance. We need multiple instances of our service in case of failure of one of our servers. Also the network can fail. Also the accidence of high load or some other problems which might suddenly surprise us. Therefore we have to think about High Availability much earlier just not to fail and to be awakened during the weekend.
