coordination #112718
Updated by okurz almost 2 years ago
## Observation We received a lot of alerts over the weekend regarding failed minion jobs and others. Checking Grafana I can see that the problem started Saturday, 18th of June around 13:00 CET: https://stats.openqa-monitor.qa.suse.de/d/WebuiDb/webui-summary?orgId=1&from=1655549105000&to=now The amount of returned PostgreSQL rows looks very suspicious and is now five times as high as before: https://stats.openqa-monitor.qa.suse.de/d/WebuiDb/webui-summary?orgId=1&from=1655475539000&to=now&viewPanel=89 ## Suggestions * Load [OSD database dump](https://progress.opensuse.org/projects/openqav3/wiki/#Backup) from after the incident started and try to reproduce the problem * Research how to find out where heavy queries come from * Research what can cause rows returned to grow from <100k to 20-60M ## Problem * **H1:** The migration to "bigint" has triggered a query planner update causing to end up with sub-optimal routing. As also auto-vacuum is eventually triggering "ANALYZE" we assume that eventually the system would recover automatically by using optimized queries. This is likely what happened on o3 after the period of 1-2 days. On OSD we do not have enough performance headroom (in particular CPU and potentially disk I/O) to cover for such periods. ## Rollback and cleanup steps * *DONE:* on osd `systemctl enable --now telegraf` * *DONE:* on osd `systemctl unmask --now salt-master` and ensure that /etc/telegraf/telegraf.d/telegraf-webui.conf is reverted * on osd `systemctl unmask --now openqa-scheduler` -> #112718#note-57 * *DONE:* Retrigger all incomplete jobs since 2022-06-18 with https://github.com/os-autoinst/scripts/blob/master/openqa-advanced-retrigger-jobs -> #112718#note-57 * *DONE:* Retrigger failed obs-sync trigger events: https://openqa.suse.de/admin/obs_rsync/ https://openqa.suse.de/admin/obs_rsync/-/pipelines * *DONE:* Retrigger failed qem-bot trigger events: https://gitlab.suse.de/qa-maintenance/bot-ng/-/pipelines * *DONE:* Retrigger failed openQA bot trigger events: https://gitlab.suse.de/qa-maintenance/openQABot/-/pipelines * *DONE:* Unmask and start on openqaworker10 and 13: `sudo systemctl unmask --now openqa-worker-cacheservice openqa-worker@{1..20}` * *DONE:* Remove /etc/openqa/templates/main/index.html.ep * Apply salt high state and check that files are back to maintained format, e.g. * *DONE:* /usr/share/openqa/script/openqa-gru * on osd `systemctl unmask --now salt-master` and ensure that /etc/telegraf/telegraf.d/telegraf-webui.conf is reverted * Unpause alerts: * Broken workers * Failed systemd services (except openqa.suse.de) * Open database connections by user * openqa-scheduler.service * salt-master.service * web UI: Too many minion job failures