MVStore: Accessing Old Versions

November 6, 2019

A while back I blogged about MVStore basics. Let’s look at the way MVStore keeps old revisions around. First, MVStore maps have a .getVersion() method and a .openVersion() method pair. With that, you can access old version previous values. A new version of the map is created on (auto-) commit.

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Bastel Proxy: HTTPS and reverse proxy for development environments

November 5, 2019

I tend to work on web applications and services which are interconnected. Different parts of the website and the services run as separate processes. In production something like NGINX does the HTTPS termination and unifies the services to a single domain. I found it useful to have HTTPS and a reverse proxy in my development environment too. Browsers complain about plain HTTPS sites and even disable certain features. Further, if your website is split across different processes and one part runs on http://localhost:8080 and other on http://localhost:8081, you can run into cross-domain issues. Also, I found it less error-prone to mirror the domain structure than having tons of localhost:{port} pointing to each other.

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OpenJDK's Flight-Recorder and Mission Control

November 4, 2019

Flight Recorder is a low overhead profiler and diagnostics events recorder for the Hotspot JVM. Java Mission Control is a software to visualize these events. It has been included for years in the Oracle JDK but used to be a commercial feature. To use it you needed to add -XX:+UnlockCommercialFeatures -XX:+FlightRecorder flags and you were not allowed to use it in production unless you paid a license.

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Mystery Jetty Threads Due To Failed Startup

October 30, 2019

Yesterday I had an app with an embedded Jetty Server which didn’t shut down properly. The main thread exited and the app had called .stop() on the Jetty server. However, the app kept running.

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Create HTTPS Certificates in Java with Bouncy Castle

October 29, 2019

Multiple times I needed to create HTTPS certificates programmatically. For example to create test certificates for HTTPS in development without complicated setup. There is surprisingly little information out there about how to create certificates programmatically in Java. Most guides OpenSSL or another command-line tool. I wanted to avoid to run an external program but wanted to do it programmatically.

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