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13d94576e5
Previously, only nodes in the 'normal' state and decommissioning nodes were included in the set of nodes participating in barrier and barrier_and_drain commands. Joining nodes are not included because they don't coordinate requests, given their cql port is closed. However, joining nodes may receive mutations from other nodes, for which they may generate and coordinate materialized view updates. If their group0 state is not synchronized it could cause lost view updates. For example: 1. On the topology coordinator, the join completes and the joining node becomes normal, but the joining node's state lags behind. Since it's not synchronized by the barrier, it could be in an old state such as `write_both_read_old`. 2. A normal node coordinates a write and sends it to the new node as the new replica. 3. The new node applies the base mutation but doesn't generate a view update for it, because it calculates the base-view pairing according to its own state and replication map, and determines that it doesn't participate in the base-view pairing. Therefore, since the joining node participates as a coordinator for view updates, it should be included in these barriers as well. This ensures that before the join completes, the joining node's state is `write_both_read_new`, where it does generate view updates. Fixes scylladb/scylladb#26976