This term describes the general operational practice of restarting backend services to overcome system failures. While popular with java deployments, this can be observed with other systems as well. I took the liberty to collect a few gems from the Internet: Restart One MongoDB Deployment (or also the manager app) DataStax OpsCenter IBM Tivoli Storage Manager Oracle SAP With all the above documentation, this obviously shows to be a widely spread industry practice that everyone should absolutely adopt right away! RestartOPs allows you to save precious time spent on debugging applications and understanding the actual problem that one is seeing. Who needs root cause analysis, when the problem simply goes away after a juicy shutdown -r now was issued. Why bother looking deeper, if one can setup that restart command in a crontab to restart your entire production stack weekly, no, daily. Hmm, why not do it hourly! This is obviously a joke! Please never do restart ops if you are serious about your production environment. The only time restarting should solve your issues when you have your parents on the phone and can’t take a closer look at the underlying problem. (Probably switched the keyboard to Japanese again) I’ve […]

In my previous post I’ve mentioned my entry to programming was first via C++ and afterwards I wandered of into the wide fields of web development. A fundamental problem back then for me was that I did not have any money and that properly running a website required you to have a static IP with a Webserver that ideally could not only deliver static content like HTML, CSS and images, but also included PHP to have dynamic content. One of those hosters, that offered free webspace was cybton.com. As it did not have any ads on the pages offered through the webspace itself and had a cool community with a bonus system, that was the one I’ve opted for. The bonus system allowed you to upgrade your webspace to get more disk space and other cool features. You could earn points to “buy” those perks by actively engaging in the community. Imagine those fake internet points from stackoverflow would allow you to get a free server. It was super successful and at its peek, the community was super active and newcomers were quickly helped with getting their project started. One thing I remember quite clearly back then was the mostly […]

So today I decided to move all my certificates from StartSSL to LetsEncrypt. Not only is StartSSL really a bad CA with recent problems, but also they limit you with several obstacles that just don’t make any sense. They really just want you to sign up for one of their “great” extended validation thingys. Over the last couple months they have really improved the web interface but still this is not enough to deal with today’s challenges of delivering secure connections to users easily. Their new APIs and StartEncrypt service are merely a late effort, trying to outbid LE with a worse service. Not worth the time or effort. The biggest problem is, that today I run multiple domains on my server and I need to provide one single certificate with all domains via Dovecot / Postfix. StartSSL allows you to have up to five domain names in the certificates they sign. (For example www.bruck.me and bruck.me would be a total of two domain names) So I’ve ran out of the possibility of using all my domains with one StartSSL certificate. Well, LE offers up to 100 domain names in one certificate. Of course wildcard certificates would be nicer, but […]

When dealing with an Android project you want to use Proguard to minify, shrink and possibly even obfuscate the code. The gains from this are huge and many smart minds have put a lot of thought into Proguard. We encountered that the TUM Campus App shrinked from 20 Megabytes to just 9 Megabytes with all the optimization in place – huge savings if you deploy it to 10k+ clients! Really if you are not using this in your project currently you must be insane! Anyways if you rely on external Libraries like Retrofit (Which is totally awesome, use it!) then you need to add some proguard rules in order to tell it what not to remove from those libs because it is really required but maybe not directly used. Mostly that is some models which get serialized and you might encounter some warnings but those don’t really are not interesting to you as a lib user. This repository has a great collection on proguard files for various libs. Use it, don’t reinvent the wheel!

When handling uploads with PHP often it can happen, that the $_FILES array is simply empty. This can occur when one of the following things is true: Check php.ini for file_uploads = On, post_max_size, and upload_max_file_size. Make sure you’re editing the correct php.ini – use phpinfo() to verify your settings. Make sure your FORM tag has the enctype=”multipart/form-data” attribute. Do not use javascript to disable your form file input field on form submission! Make sure your directory has read+write permissions set for the tmp and upload directories. Make sure your FORM tag has method=”POST”. GET requests do not support multipart/form-data uploads. Make sure your file destination and tmp/upload directories do not have spaces in them. Make sure all FORMs on your page have /FORM close tags. Make sure your file input tag has a NAME attribute. An ID attribute is NOT sufficient! ID attributes are for use in the DOM, not for POST payloads. Your /tmp folder is full Hope this helps!