add a flag to 'add' and 'pin' to avoid pinning them locally

[RubenKelevra]

Describe the feature you are proposing

It would be nice if we can specify a flag which changes the allocation for the cluster, to exclude the local peer from beeing selected as a pinning member.

Would be nice if we can also exclude all trusted nodes.

Naming ideas:

--no-local-pin
--no-trusted-nodes-pin

Feel free to use different ones, since those are probably not good.

Usecases

If you got a cluster with a lot of traffic, you might want to avoid that the local node gets selected as pin, to avoid that it has to provide data for read operations.

This can speed up the cluster's write operations, because there's more bandwidth available to write new data to the cluster.

It also reduces the amount of traffic needed to run a trusted node, which might matter in terms of traffic costs.

[hsanjuan]

So something like an Exclude pin option that blacklist peer IDs for allocations.

[RubenKelevra]

Yes, exactly.

[RubenKelevra]

@hsanjuan this would also reduce the IO in my use-case: I add all the data to my MFS, and when I changed everything I run the pinning operation with ipfs-cluster-ctl pin update followed by an ipfs-cluster-ctl pin rm of the old cluster pin.

Since I cannot set --no-local-pin on my cluster, my local node will start analyzing the full pin, which takes like 4 minutes even on an SSD: