Upgrade mccb
By the end of this page mccb will run a newer image with your data intact.
docker compose pull && docker compose up -dIf you pinned a version, change the tag in docker-compose.yml first. Read the changelog before a minor or major version.
Back up ./data first: see Back up and restore.
Check the version
Section titled “Check the version”The version is shown in the sidebar footer and on the login screen, returned by GET /api/version (public) and GET /api/health, and logged when web and worker start.
It comes from app/VERSION. Docker builds can override it with --build-arg VERSION=<tag> (CI passes the tag) and --build-arg GIT_SHA=<sha>. Without VERSION the app shows <file>+<sha>, for example 1.1.1+<sha>.
Notes for older installs
Section titled “Notes for older installs”Servers created by earlier versions become Auto tuning when workers was a default (2 in the 1.0.0 UI, 4 in the schema). Any other value was chosen by hand and stays Manual. See Tune builders and IMAP connections.
Stop and start without losing a job
Section titled “Stop and start without losing a job”On SIGTERM the worker gives subprocesses CHILD_TERM_GRACE seconds (20 by default) to stop, then jobs go back to the queue and resume later. The compose file allows the worker 30 seconds (stop_grace_period).