cluster: expel instances removed from config in cluster.sync #424
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luatest/cluster.lua
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| for _, iserver in pairs(old_server_map) do | ||
| iserver:drop() | ||
| end |
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That's interesting. We don't start new instances in :sync(), just create server objects in Lua. So, it looks like we shouldn't stop them too.
But,
- If we don't stop the server, it remains running after the test case.
- A user may want some automation about synchronization of the configured and present instances.
The first point is simple: just track the excluded server objects in some list to call :drop() on it in the after_each hook. self._excluded_server_map or something like this. We can also reuse the server object from this mapping if a previously deleted server is added again.
The second point is really interesting. Since tarantool 3.3 a user can configure autoexpelling if needed. So, we really need just update the config and start/stop processes to manage the cluster.
It looks like we really have two suitable methods:
- update config + update server objects
- update config + update server objects + start/stop processes
The first one is what :sync() do now. We can implement the second as a :sync() option. What do you think?
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Makes sense, thanks for the suggestion. Now, cluster:sync() moves removed instances to a separate list to be dropped along with the cluster. Also, added the new option start_stop, which makes cluster:sync() start/stop added/removed instances.
Currently, cluster:sync() leaves instances removed from the config in the instance list. This makes cluster:reload() fail because it tries to reload the config for all instances including those that are not in the config anymore. To fix that, let's make cluster:sync() move instances that were removed from the config to the special expelled instance list so that they become inaccessible via cluster but are still dropped by cluster:drop(). Also, let's add the new boolean option start_stop for cluster:sync(). If set, cluster:sync() will stop old servers and start new ones. Closes tarantool#423
locker
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Currently,
cluster:sync()leaves instances removed from the config in the instance list. This makescluster:reload()fail because it tries to reload the config for all instances including those that are not in the config anymore. To fix that, let's makecluster:sync()move instances that were removed from the config to the special expelled instance list so that they become inaccessible via cluster but are still dropped bycluster:drop().Also, let's add the new boolean option
start_stopforcluster:sync(). If set,cluster:sync()will stop old servers and start new ones.Closes #423