feedback: Module vshard

[TarantoolBot]

Every Tarantool space you plan to shard |must have a bucket id field indexed by the
bucket id index.| Spaces without the bucket id indexes don’t participate in shard<…>

https://www.tarantool.io/en/doc/2.2/reference/reference_rock/vshard/#virtual-buckets

Guess bucket_id should be highlighted as code and include underscore in it's name.

Also, are there any requirements on a field type/nullability. And on index type uniqueness?

[rosik]

FYI

https://github.com/tarantool/vshard/blob/728b8ba981d9e6298d3edb809caac7751b4bcdff/vshard/storage/init.lua#L61-L64

https://github.com/tarantool/vshard/blob/728b8ba981d9e6298d3edb809caac7751b4bcdff/vshard/storage/init.lua#L868-L886

[v-izmalkov]

As i understand there is a bigger issue with vshard documentation - improvements needed for users to better understand sharding of a space step by step. I suggest adding a tutorial, probably based on the example configuration or similar. The tutorial shall have step by step instructions to sharding a space and sufficient illustrations and descriptions of each step for users to fully understand this process.

[lenkis]

I added information within this ticket (revised info on bucket id field and shard index).

Writing a tutorial is a big task; will create another ticket for that.