Upcoming sets of proposals adding and removing nodes from the app subnet io67a

In the upcoming days we will be creating sets of proposals that are adding and removing nodes from the app subnet io67a. In this post we want to explain the background for these proposals.

In December we rolled out a replica version that contained this commit implementing a feature to enable upgrades of unassigned nodes to a specified version because we had incompatibility issues with unassigned nodes running a stale version of replica. However, we are still not able to update the nodes in unassigned mode because the replica version running on those does not implement this feature.

Another feature, rolled out in the last week of January, allows the un-assignment of nodes from a subnet: whenever a node discovers that it’s not assigned to a subnet anymore, it deletes its subnet state and goes into the unassigned mode in which it starts monitoring the registry for a new subnet assignment.
In a one-time series of proposals we will now upgrade all currently unassigned nodes running older replica versions which do not support the upgrades. This will be done by assigning these nodes to an existing subnet which will effectively force them to upgrade to the replica version of the subnet which will include the unassigned node upgrade functionality. After that we will un-assign these nodes again making them ready to use in other subnets.