Admin tools development/Global CheckUser

It has been requested by numerous parties that the ability to run checkuser across multiple wiki simultaneously would enhance Stewards' ability to locate and block spam bots.

Requirements

 * Current local tool exists at m:Special:CheckUser; propose a parallel one at m:Special:GlobalCheckUser.
 * Accessed through new permissions ( and  ) - will be granted to the Stewards group, but should be a granular.
 * Will re-use local tool's code as much as possible to avoid code repetition/divergence.
 * Logged to a single global CU log, which will include all CUs, local and global, visible for those with  right.

Workflow

 * On m:Special:GlobalCheckUser, user uses tool as on m:Special:CheckUser.
 * Tool uses existing (where possible) functions to run CU on local wikis
 * Results are returned to a single UI on Meta

Questions

 * Where are log entries placed? Global CU log - Hard for local wikis to see the global action or Local CU log - Could potentially be a lot of log spam and cause many questions // could place in local log and identify them as global CU as an FYI An integrated global log is the preferred answer.
 * What does the global search results set look like? (Do we group by wiki, by action type, by IP, by day)?
 * Are smaller limits needed given the potential to slow all wikis down at once?
 * Could you please explain the sentence "Logged to a single global CU log, which will include all CUs, local and global." - will the people with access to global checkuser (stewards I assume) be able to see the CU logs of all wikis including the global ones in one ( this is what I would support as right now we're not able to check the local activity while that's part of our job ) OR will all checkusers of all wikis be able to see the global CU log, which basically only contains the CU actions of stewards via global checkuser? Trijnstel (talk) 21:46, 14 February 2013 (UTC) - The former; otherwise this would be releasing information to local CUs. Jdforrester (WMF) (talk) 21:49, 14 February 2013 (UTC)
 * As stewards are only allowed to CU on projects without CUs (with exceptions of course), is it only possible to use this tool only on those wikis? Trijnstel (talk) 21:46, 14 February 2013 (UTC)
 * We could build the tool to respect a wikiset, but this would defeat a lot of the point of a pan-wiki tool. Jdforrester (WMF) (talk) 21:49, 14 February 2013 (UTC)
 * I agree, the policy empowers stewards to perform checks when needed for crosswiki issues, and by the user of this tool would be Stewards and WMF staff, and obviously only for crosswiki issues, else there would be no point in using it. Should it be felt that the policy does not the allow the usage of this tool, I suggest that the policy be updated. New tools being deployed might at times require updating of policies of course, but the fact that policies are not yet equipped to deal with no tools only means that they should be updated, not that tool development should be forever halted until policies allow it. In any case, I believe this tool is indeed allowed by the checkuser policy, as it would obviously only used for crosswiki issues. Snowolf How can I help? 21:57, 14 February 2013 (UTC)
 * Yep, agreed with Snowolf. As a follow-up to my question: what if we check a /16 range and we find out that it has LOTS of traffic on multiple wikis, so much that the page doesn't load -- how can we prevent that? (besides checking a smaller range) I was thinking about a collapse tool so that you can 'open' up the different wikis. Mathonius suggested to use checkboxes, 1 for all projects, 1 for only wiktionaries/wikibooks/etc and 1 for only the projects without CUs (for example)? Trijnstel (talk) 22:06, 14 February 2013 (UTC)