It should be allowed to run phase 1 if zones are used

Kal,

Is there any good reason for not allowing phase 1 to be executed on a zoned collection? If there is none, then it should be allowed.

workscripts/ctools/defragment_sharded_collection.py

Line 205 in d26bd02

tags_doc = await cluster.configDb.tags.find_one({'ns': args.ns})

Dmitry

Technically there is no fundamental reason why only Phase 1 should not be able to run on a zoned collection, because it only does merges. Problem is with Phase 2, which moves chunks and the script is not aware of zones.

So @dryabtse , if you want to "comment-out" that part for some customer, feel free, but you need to be very careful to stop the script before it reaches to the next Phase.

CC @toto-dev

@ppolato just pointed out to me that if we have two or more zones which overlap on the same shard, Phase1 will merge the chunks across the zones. This will not constitute a zone violation, because the balancer later on will split them again at the zone boundaries.