# Upgrading to Gerrit 2.15: a real-life story on GerritHub.io

Upgrading is always a pain: learning from other people's mistakes
is the only way to plan for a flawless transition to new releases.

GerritHub.io has been upgraded successfully to Gerrit 2.15 back in
April with zero-downtime but some [bumps on the road](https://gitenterprise.me/2018/04/27/gerrithub-is-on-notedb-with-a-bump/).

See how the process worked and discuss with Luca Milanesio the challenges and tricks to migrate to Gerrit 2.15 and NoteDb without impacting your users:

- How to plan the upgrade
- What to expect in terms of resources utilisation
- Disaster recovery plan
- Monitoring
- Split between reindex phase and NoteDb on-line migration
- Post-upgrade metrics
- Retrospective after 6 months on Gerrit 2.15/NoteDb

*[Luca Milanesio, Gerrit Maintainer - GerritForge Ltd](../speakers.md#lmilanesio)*