Upgrade Experience

This page describes the points for the upgrade schecdule

Sites Upgrading, their previous state and reasons to upgrade

UKI-SOUTHGRID-RALPP
- Running pnfs
  - Slow performance
- dCache 1.9.4-X
  - This was not a golden release
UKI-LT2-IC-HEP
- Running pnfs
  - Slow performance
- dCache 1.9.2-X
  - This had been stable but unsupported for approx 6 months
Aim had been to deploy golden release before data taking
- Data taking and release in production of a golden release both kept slipping

Upgrade went well
- (This was unexpected!)
Both sites main issue was with the postgres database upgrade for Chimera.
Site tested upgrading procedure before hand on spare hardware.
- Site tried upgrade dCache central servers and to convert from pnfs to chimera at the same time with problems.
- Site found tracking upgrade issues decoupled if only upgrading one conmponent at a time.
  - Recommend not to upgrade services and database upgrade at the same time.
- Testing Good
- Experience shared with other less dCache experienced Sys admin at other sites
  - (Staged rollout as a concept was a good idea)
Overall upgrade proceeded with fewer unexpecte breakages of services
- Midleware itself more stable and intuitive
  - One upgrade was enacted by a new dCache sys-admin
  - Testing of upgrade by experienced sys-admin on spare hardware invaluable.