PHP syntax error caused 48-hour web site downtime
Today I realized my web site had been serving an empty HTML document for the last 2 days on every HTTP request no matter what the path was. When I initially noticed the issue, I was a bit worried, but, after taking a closer look at the Apache error log, I found out about a PHP syntax error causing the issue. A couple of days ago I had edited a WordPress plugin on my live web site and, apparently, I made a typo which led to a syntax error and an empty document being served on every request. But, I recall I had checked the website after the modification of the plugin but I hadn’t noticed any issues! Actually, this happened because I had forgot to clear the cache, so when I checked the site after the modification of the plugin, it seemed OK. My modification didn’t change the visual representation of the web site, so, having forgot to turn off caching, there was no way for me to find out about the typo. Lesson learned: never modify the code of a live web site, but, if you have to do it, always turn-off caching before doing so.
