As part of {T179417}, capacity will need to be moved from the legacy cluster to the new, by first decommissioning the instances on one host in each rack (6 total), re-imaging them, and bootstrapping them into the new (Cassandra 3.x) cluster.
The hosts to be decommissioned (in order):
* [x] 2002 (codfw, rack b)
* [x] 2004 (codfw, rack c)
* [x] 2006 (codfw, rack d)
* [x] 1007 (eqiad, rack a)
* [x] 1012 (eqiad, rack b)
* [x] 1014 (eqiad, rack d)
Nodes to be bootstrapped:
* [x] 2002
* [x] a
* [x] b
* [x] c
* [x] 2006
* [x] a
* [x] b
* [x] c
* [ ] 2004
* [ ] a
* [ ] b
* [ ] c
* [ ] 1007
* [ ] a
* [ ] b
* [ ] c
* [ ] 1012
* [ ] a
* [ ] b
* [ ] c
* [ ] 1014
* [ ] a
* [ ] b
* [ ] c
Post-bootstrap cleanups:
* [ ] 2001
* [ ] a
* [ ] b
* [ ] c
* [ ] 2003
* [ ] a
* [ ] b
* [ ] c
* [ ] 2005
* [ ] a
* [ ] b
* [ ] c
* [ ] 1007
* [ ] a
* [ ] b
* [ ] c
* [ ] 1012
* [ ] a
* [ ] b
* [ ] c
* [ ] 1014
* [ ] a
* [ ] b
* [ ] c
NOTE: 2006 was intentionally reordered to happen before 2004 in order to side-step {T180562} for now