dealings with diverse tech challenges

Change default SSHD port on VPS

When your firewall it not setup to filter out traffic from all but certain IP addresses, you will often notice many failed SSH login attempts. My CentOS servers will notify me of this when I login with a message like this: »

Adding an index to an existing Mysql table

Adding an index to an existing Mysql table turns out to be easy. And it is fast too. I added an index to a table with roughly 10 million rows. It took the database less than 2 minutes to add the index. »

JHipster: Update your database using Liquibase

A Java project generated with JHipster will use Liquibase to manage database updates. Rather than simply updating or adding a JPA entity in your code and letting Hibernate update your database for you, JHipster requires that you update your database change log and the Liquibase configuration file 'master.xml'.  »

Changing Nginx request timeout

Calls fired by my application suddenly started to timeout in a production environment. A colleague was quick to point towards the web server. Nginx has a default time out value of 60 seconds. In this case, the requests were large data imports which frequently took more than a minute. Changing the timeout in Nginx is easy. »

Creating a new sudo user on CentOS 7

One of the first things I want to do after a new CentOS 7 install on a remote server is the creation of a new user with sudo privileges. Doing so is easy. »

Java not trusting Letsencrypt certificates

A while ago, I ran into an issue where REST calls triggered from within my Java application to a different Java Api running on another server failed, even though everything worked in my test environment. The stack trace showed the following exception: »