With T166802, T177017 and their subtasks, the filter profiling is slowly being re-added to wikis. In fact, from the time it was disabled, it's now more performant and will possibly be even better after patches like [[https://gerrit.wikimedia.org/r/#/c/201104/ | this ]] will be merged. So I'm proposing to set both $wgAbuseFilterProfile and $wgAbuseFilterRuntimeProfile true by default (and also rename them), to give a heavy help to filter mantainers. Of course, the patch itself is straightforward to write, but I'd first like to hear some thoughts, although I think the reasons that caused profiling to be disabled don't exist anymore. Adding as subscribers some people from previous related tasks.
==Current status (Jan 24th)==
Profiling is now enabled everywhere in production. We should wait a couple of weeks to see if any problem arises, especially the ones outlined in https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/AbuseFilter/+/211951/. If everything is fine, the next step is https://gerrit.wikimedia.org/r/486279 + https://gerrit.wikimedia.org/r/486280 to remove the global from AbuseFilter and WMF config.
In the meanwhile, we have to understand whether enabling $wgAbuseFilterRuntimeProfile everywhere would be safe. If so, we should then follow a similar process: enable it for every wiki, wait a couple of weeks, then if everything is fine remove it from AbuseFilter and WMF config. Regardless of this, https://gerrit.wikimedia.org/r/486284 should be merged to add some more light stats.
== Questions for #performance-team ==
[] Is Xenon happy with profiling, currently enabled everywhere? The recording method is `AbuseFilter::recordProfilingResult`, and what it does is get and set 3 stash keys for every active filter for every action (edit, move, delete, account (auto)creation and upload), in a deferredupdate. (See "future plans" below for improvements)
[] Would Graphite be OK with new profiling data from every wiki? The recording method is `AbuseFilter::recordRuntimeProfilingResult`, and what it does is update 3 statsd keys for every edit. See [[https://gerrit.wikimedia.org/g/operations/mediawiki-config/+/e82eefb9f3a73e9cd4e6f153e64ccb6ab7206dbf/wmf-config/InitialiseSettings.php#14064|here]] a list of wikis where this is already in place.
==Future plans==
The final goal of this task is to have all profiling enabled by default and drop profiling globals. Once that will be done, patches like https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/AbuseFilter/+/478232/ will be easier to write and, starting with https://gerrit.wikimedia.org/r/#/c/mediawiki/extensions/AbuseFilter/+/201104/, we'll add profiling data on-wiki, possibly making it more efficient. The latter will also change the profiling system so that recordProfilingResult will only use a single stash key for every filter.