2017-10-21 UPDATE: attend this session in French at DrupalCamp Lannion next week !

These are the slides of the presentation I gave yesterday at DrupalDevDays Milan.

Graylog is, in the words of its creators, a tool to Store, search & analyze log data from any source, and it puts a lot of power in our hands to slice, dice, and generally combine, gather, and parse content from various sources, notably syslog and Gelf sources, as well as many file-type sources thanks to the Graylog Collector. Which means it makes it a snap to build event-oriented dashboards like the left part of this example, and even some event volume graphs like the topmost one on the right.

The problem: logging non-event information

This covers only logged events, which is fine overall, since Graylog is a log analysis platform, not a graph-oriented monitoring system like Munin / Cati / Ganglia et alii. However, in many cases, especially when building dashboards instead of performing some specific research, one may want to keep an eye on average system load, or other non-event information, if only to know when to switch one's attention to the monitoring system.

So how can one add system load information, which is not event-based, to a log dashboard like the three bottom-right graphs on the previous dashboard ?

The problem

When running tests on a server using the recent versions of the MongoDB module for Drupal, and more specifically the MongoDB simpletests, the simpletest runner may leave droppings in your MongoDB Drupal database, which have no business remaining there. How to remove them while keeping the good collections ?

The typical case will be after a failed test runs, looking like this:

When auditing or reviewing an unknown code base, I often have to decide which files to examine in priority. Beyond the usual heuristics for Drupal projects (hint: look at templates in D7), how can one find the parts most likely to contain problems ? This simple command set can help pinpoint troublemaking files quickly.

One of the big trends during the Drupal 8 creation has been the replacement of info hooks by two main mechanisms: annotations, and YAML files. In that light, hook_drush_command(), as the CLI equivalent of the late hook_menu, replaced by various YAML files, looks just like a perfect candidate for replacement by a commands section in some mymodule.drush.yml configuration file. Turns out it is incredibly easy to achieve. Let's see how to kill some hundred lines of code real fast !

One nice thing during Drupal 7/8 development is the ability, thanks to the devel module, to get a list of all SQL queries ran on a page. As I've been working quite a bit on MongoDB in PHP recently, I wondered how to obtain comparable results when using MongoDB in PHP projects. Looking at the D7 implementation, the magic happens in the Database class:

With DBTNG, that's all it takes, and devel puts it to good use UI-wise. So is there be an equivalent mechanism in MongoDB ? Of course there is !

While porting (well, actually rewriting) an old PHP library to Go, I had to use a CRC (cyclic redundancy check) on a buffer. In old-school PHP, the standard is well established since PHP 4: just use crc32 from the strings package, and beware of the sign bit or, to be a bit more current while still compatible, use the hash() function from the hash package, like this example: