Shutdown of master in semisync when it's in sync can let more transactions in the master than the slaves.
This is expected in case of a crash as the binlog write before send and wait for the ACK. But this is an issue in case of regular shutdown, as the workload can not be safely be moved to a slave.
We can make sure the semi sync thread is killed last in shutdown and stopped only if status move to no sync or after receiving the ACK , this would possibly delay shutdown for the maximum time of the rpl_semi_sync_master_timeout
{"report":{"fcp":2868.7000000476837,"ttfb":988.5,"pageVisibility":"visible","entityId":59893,"key":"jira.project.issue.view-issue","isInitial":true,"threshold":1000,"elementTimings":{},"userDeviceMemory":8,"userDeviceProcessors":64,"apdex":0.5,"journeyId":"bc3a8b55-6651-4b45-b3c2-d799d6591577","navigationType":0,"readyForUser":2940.2000000476837,"redirectCount":0,"resourceLoadedEnd":3724.9000000953674,"resourceLoadedStart":994.7000000476837,"resourceTiming":[{"duration":1207.4000000953674,"initiatorType":"link","name":"https://jira.mariadb.org/s/2c21342762a6a02add1c328bed317ffd-CDN/lu2cib/820016/12ta74/0a8bac35585be7fc6c9cc5a0464cd4cf/_/download/contextbatch/css/_super/batch.css","startTime":994.7000000476837,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":994.7000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":2202.100000143051,"responseStart":0,"secureConnectionStart":0},{"duration":1207.5,"initiatorType":"link","name":"https://jira.mariadb.org/s/7ebd35e77e471bc30ff0eba799ebc151-CDN/lu2cib/820016/12ta74/494e4c556ecbb29f90a3d3b4f09cb99c/_/download/contextbatch/css/jira.browse.project,project.issue.navigator,jira.view.issue,jira.general,jira.global,atl.general,-_super/batch.css?agile_global_admin_condition=true&jag=true&jira.create.linked.issue=true&slack-enabled=true&whisper-enabled=true","startTime":994.9000000953674,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":994.9000000953674,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":2202.4000000953674,"responseStart":0,"secureConnectionStart":0},{"duration":1217.5999999046326,"initiatorType":"script","name":"https://jira.mariadb.org/s/0917945aaa57108d00c5076fea35e069-CDN/lu2cib/820016/12ta74/0a8bac35585be7fc6c9cc5a0464cd4cf/_/download/contextbatch/js/_super/batch.js?locale=en","startTime":995.1000001430511,"connectEnd":995.1000001430511,"connectStart":995.1000001430511,"domainLookupEnd":995.1000001430511,"domainLookupStart":995.1000001430511,"fetchStart":995.1000001430511,"redirectEnd":0,"redirectStart":0,"requestStart":995.1000001430511,"responseEnd":2212.7000000476837,"responseStart":2212.7000000476837,"secureConnectionStart":995.1000001430511},{"duration":1346.6999998092651,"initiatorType":"script","name":"https://jira.mariadb.org/s/2d8175ec2fa4c816e8023260bd8c1786-CDN/lu2cib/820016/12ta74/494e4c556ecbb29f90a3d3b4f09cb99c/_/download/contextbatch/js/jira.browse.project,project.issue.navigator,jira.view.issue,jira.general,jira.global,atl.general,-_super/batch.js?agile_global_admin_condition=true&jag=true&jira.create.linked.issue=true&locale=en&slack-enabled=true&whisper-enabled=true","startTime":995.3000001907349,"connectEnd":995.3000001907349,"connectStart":995.3000001907349,"domainLookupEnd":995.3000001907349,"domainLookupStart":995.3000001907349,"fetchStart":995.3000001907349,"redirectEnd":0,"redirectStart":0,"requestStart":995.3000001907349,"responseEnd":2342,"responseStart":2341.9000000953674,"secureConnectionStart":995.3000001907349},{"duration":1350.4000000953674,"initiatorType":"script","name":"https://jira.mariadb.org/s/a9324d6758d385eb45c462685ad88f1d-CDN/lu2cib/820016/12ta74/c92c0caa9a024ae85b0ebdbed7fb4bd7/_/download/contextbatch/js/atl.global,-_super/batch.js?locale=en","startTime":995.5,"connectEnd":995.5,"connectStart":995.5,"domainLookupEnd":995.5,"domainLookupStart":995.5,"fetchStart":995.5,"redirectEnd":0,"redirectStart":0,"requestStart":995.5,"responseEnd":2345.9000000953674,"responseStart":2345.9000000953674,"secureConnectionStart":995.5},{"duration":1350.7000000476837,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:calendar-en/jira.webresources:calendar-en.js","startTime":995.7000000476837,"connectEnd":995.7000000476837,"connectStart":995.7000000476837,"domainLookupEnd":995.7000000476837,"domainLookupStart":995.7000000476837,"fetchStart":995.7000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":995.7000000476837,"responseEnd":2346.4000000953674,"responseStart":2346.4000000953674,"secureConnectionStart":995.7000000476837},{"duration":1350.9000000953674,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:calendar-localisation-moment/jira.webresources:calendar-localisation-moment.js","startTime":995.9000000953674,"connectEnd":995.9000000953674,"connectStart":995.9000000953674,"domainLookupEnd":995.9000000953674,"domainLookupStart":995.9000000953674,"fetchStart":995.9000000953674,"redirectEnd":0,"redirectStart":0,"requestStart":995.9000000953674,"responseEnd":2346.800000190735,"responseStart":2346.800000190735,"secureConnectionStart":995.9000000953674},{"duration":1405,"initiatorType":"link","name":"https://jira.mariadb.org/s/b04b06a02d1959df322d9cded3aeecc1-CDN/lu2cib/820016/12ta74/a2ff6aa845ffc9a1d22fe23d9ee791fc/_/download/contextbatch/css/jira.global.look-and-feel,-_super/batch.css","startTime":996,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":996,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":2401,"responseStart":0,"secureConnectionStart":0},{"duration":1351.1000001430511,"initiatorType":"script","name":"https://jira.mariadb.org/rest/api/1.0/shortcuts/820016/47140b6e0a9bc2e4913da06536125810/shortcuts.js?context=issuenavigation&context=issueaction","startTime":996.2000000476837,"connectEnd":996.2000000476837,"connectStart":996.2000000476837,"domainLookupEnd":996.2000000476837,"domainLookupStart":996.2000000476837,"fetchStart":996.2000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":996.2000000476837,"responseEnd":2347.300000190735,"responseStart":2347.300000190735,"secureConnectionStart":996.2000000476837},{"duration":1415.7999999523163,"initiatorType":"link","name":"https://jira.mariadb.org/s/3ac36323ba5e4eb0af2aa7ac7211b4bb-CDN/lu2cib/820016/12ta74/d176f0986478cc64f24226b3d20c140d/_/download/contextbatch/css/com.atlassian.jira.projects.sidebar.init,-_super,-project.issue.navigator,-jira.view.issue/batch.css?jira.create.linked.issue=true","startTime":996.4000000953674,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":996.4000000953674,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":2412.2000000476837,"responseStart":0,"secureConnectionStart":0},{"duration":1351.4000000953674,"initiatorType":"script","name":"https://jira.mariadb.org/s/5d5e8fe91fbc506585e83ea3b62ccc4b-CDN/lu2cib/820016/12ta74/d176f0986478cc64f24226b3d20c140d/_/download/contextbatch/js/com.atlassian.jira.projects.sidebar.init,-_super,-project.issue.navigator,-jira.view.issue/batch.js?jira.create.linked.issue=true&locale=en","startTime":996.5,"connectEnd":996.5,"connectStart":996.5,"domainLookupEnd":996.5,"domainLookupStart":996.5,"fetchStart":996.5,"redirectEnd":0,"redirectStart":0,"requestStart":996.5,"responseEnd":2347.9000000953674,"responseStart":2347.9000000953674,"secureConnectionStart":996.5},{"duration":2726.7999999523163,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:bigpipe-js/jira.webresources:bigpipe-js.js","startTime":997.6000001430511,"connectEnd":997.6000001430511,"connectStart":997.6000001430511,"domainLookupEnd":997.6000001430511,"domainLookupStart":997.6000001430511,"fetchStart":997.6000001430511,"redirectEnd":0,"redirectStart":0,"requestStart":997.6000001430511,"responseEnd":3724.4000000953674,"responseStart":3724.4000000953674,"secureConnectionStart":997.6000001430511},{"duration":2727.2000000476837,"initiatorType":"script","name":"https://jira.mariadb.org/s/d41d8cd98f00b204e9800998ecf8427e-CDN/lu2cib/820016/12ta74/1.0/_/download/batch/jira.webresources:bigpipe-init/jira.webresources:bigpipe-init.js","startTime":997.7000000476837,"connectEnd":997.7000000476837,"connectStart":997.7000000476837,"domainLookupEnd":997.7000000476837,"domainLookupStart":997.7000000476837,"fetchStart":997.7000000476837,"redirectEnd":0,"redirectStart":0,"requestStart":997.7000000476837,"responseEnd":3724.9000000953674,"responseStart":3724.9000000953674,"secureConnectionStart":997.7000000476837},{"duration":803.2000000476837,"initiatorType":"xmlhttprequest","name":"https://jira.mariadb.org/rest/webResources/1.0/resources","startTime":2484.9000000953674,"connectEnd":2484.9000000953674,"connectStart":2484.9000000953674,"domainLookupEnd":2484.9000000953674,"domainLookupStart":2484.9000000953674,"fetchStart":2484.9000000953674,"redirectEnd":0,"redirectStart":0,"requestStart":2484.9000000953674,"responseEnd":3288.100000143051,"responseStart":3288.100000143051,"secureConnectionStart":2484.9000000953674},{"duration":872.2999999523163,"initiatorType":"script","name":"https://www.google-analytics.com/analytics.js","startTime":2859.100000143051,"connectEnd":0,"connectStart":0,"domainLookupEnd":0,"domainLookupStart":0,"fetchStart":2859.100000143051,"redirectEnd":0,"redirectStart":0,"requestStart":0,"responseEnd":3731.4000000953674,"responseStart":0,"secureConnectionStart":0}],"fetchStart":0,"domainLookupStart":0,"domainLookupEnd":0,"connectStart":0,"connectEnd":0,"requestStart":831,"responseStart":989,"responseEnd":990,"domLoading":992,"domInteractive":3761,"domContentLoadedEventStart":3761,"domContentLoadedEventEnd":3823,"domComplete":4955,"loadEventStart":4955,"loadEventEnd":4955,"userAgent":"Mozilla/5.0 AppleWebKit/537.36 (KHTML, like Gecko; compatible; ClaudeBot/1.0; +claudebot@anthropic.com)","marks":[{"name":"bigPipe.sidebar-id.start","time":3732.600000143051},{"name":"bigPipe.sidebar-id.end","time":3733.5},{"name":"bigPipe.activity-panel-pipe-id.start","time":3733.600000143051},{"name":"bigPipe.activity-panel-pipe-id.end","time":3735.2000000476837},{"name":"activityTabFullyLoaded","time":3839.5}],"measures":[],"correlationId":"4e149af3a7ece5","effectiveType":"4g","downlink":9,"rtt":0,"serverDuration":105,"dbReadsTimeInMs":17,"dbConnsTimeInMs":27,"applicationHash":"9d11dbea5f4be3d4cc21f03a88dd11d8c8687422","experiments":[]}}
Bug
Major
MDEV-28114 Semi-sync Master ACK Receiver Thread Can Error on COM_QUIT
MDEV-18450has partly fixed this issue. The remained work is to further delay the master shutdown until either an ackarrives or rpl_semi_sync_master_timeout elapses.