How are we doing in our strive for operational excellence? Read on to find out!

Incidents

7 documented incidents in July, and 4 in August (Incident graphs https://codepen.io/Krinkle/full/wbYMZK). Read more about past incidents at Incident status https://wikitech.wikimedia.org/wiki/Incident_status on Wikitech.

2022-07-03 shellbox https://wikitech.wikimedia.org/wiki/Incidents/2022-07-03_shellbox_request_spike Impact: For 16 minutes, edits and previews for pages with Score musical notes were slow or unavailable.

2022-07-10 thumbor https://wikitech.wikimedia.org/wiki/Incidents/2022-07-10_thumbor Impact: For several days, Thumbor p75 service response times gradually regressed by several seconds.

2022-07-11 FrontendUnavailable cache text https://wikitech.wikimedia.org/wiki/Incidents/2022-07-11_FrontendUnavailable_cache_text Impact: For 5 minutes, the MediaWiki API cluster in eqiad responded with higher latencies or errors.

2022-07-11 Shellbox and parsoid saturation https://wikitech.wikimedia.org/wiki/Incidents/2022-07-11_Shellbox_and_parsoid_saturation Impact: For 13 minutes, the mobileapps service was serving HTTP 503 errors to clients.

2022-07-12 codfw A5 power cycle https://wikitech.wikimedia.org/wiki/Incidents/2022-07-12_codfw_A5_powercycle Impact: No observed public-facing impact. Internal clean up took some work, e.g. for Ganeti VMs.

2022-07-13 eqsin bandwidth https://wikitech.wikimedia.org/wiki/Incidents/2022-07-13_brief_outbound_bandwidth_spike_eqsin Impact: For 20 minutes, there was a small increase in error responses for thumbnails served from the Eqsin data center (Singapore).

2022-07-20 eqiad network https://wikitech.wikimedia.org/wiki/Incidents/2022-07-20_network_interruption Impact: For 10-15 minutes, a portion of wiki traffic from Eqiad-served regions was lost (about 1M uncached requests). For ~30 minutes, Phabricator was unable to access its database.

2022-08-10 cassandra disk space https://wikitech.wikimedia.org/wiki/Incidents/2022-08-10_cassandra_disk_space Impact: During planned downtime, other hosts ran out of space due to accumulating logs. No external impact.

2022-08-10 confd all hosts https://wikitech.wikimedia.org/wiki/Incidents/2022-08-10_confd_all_hosts Impact: No external impact.

2022-08-16 Beta Cluster 502 https://wikitech.wikimedia.org/wiki/Incidents/2022-08-16_Beta_Cluster_502 Impact: For 7 hours, all Beta Cluster sites were unavailable.

2022-08-16 x2 database replication https://wikitech.wikimedia.org/wiki/Incidents/2022-08-16_x2_databases_replication_breakage Impact: For 36 minutes, errors were noticeable for some editors. Saving edits was unaffected.

Incident follow-up Recently completed incident follow-up:

Replace certificate on elastic09 in Beta Cluster https://phabricator.wikimedia.org/T315386 Brian (bking, WMF Search) noticed during an incident review that an internal server used an expired cert and renewed it in accordance with a documented process.

Localisation cache must be purged after train deploy https://phabricator.wikimedia.org/T263872 Tchanders (WMF AHT) filed this in 2020 after a recurring issue with stale interface labels. Work led by Ahmon (dancy, WMF RelEng).

Remember to review and schedule Incident Follow-up work https://phabricator.wikimedia.org/project/view/4758/ in Phabricator! These are preventive measures and tech debt mitigations written down after an incident is concluded. Highlight from the "Oldest incident follow-up" query:

* T83729 https://phabricator.wikimedia.org/T83729 Fix monitoring of poolcounter service.

Trends

The month of July saw 22 new production errors https://phabricator.wikimedia.org/maniphest/query/XHYmsxx4VNRI/#R of which 9 are still open today. In August we encountered 29 new production errors https://phabricator.wikimedia.org/maniphest/query/BnX.PiwEomZt/#R of which 10 remain open today and have carried over to September.

Take a look at the workboard and look for tasks that could use your help. → https://phabricator.wikimedia.org/tag/wikimedia-production-error/

💡 *Did you know?* To zoom in and find your team's error reports, use the appropriate "Filter" link in the sidebar https://phabricator.wikimedia.org/tag/wikimedia-production-error/ of the workboard. For the month-over-month numbers, refer to the spreadsheet data https://docs.google.com/spreadsheets/d/e/2PACX-1vTrUCAI10hIroYDU-i5_8s7pony8M71ATXrFRiXXV7t5-tITZYrTRLGch-3iJbmeG41ZMcj1vGfzZ70/pubhtml.

Thanks!

Thank you to everyone who helped by reporting, investigating, or resolving problems in Wikimedia production. Thanks!

Until next time,

– Timo Tijhof

🔗 Share or read later via https://phabricator.wikimedia.org/phame/post/view/296/