Using Watchers Callbacks
Explore how to use Tooz library watchers callbacks to manage group membership events in distributed systems. Learn to register, unregister, and run callback functions that respond to members joining or leaving groups. This lesson helps you handle asynchronous group membership changes robustly, improving your distributed Python applications’ responsiveness and reliability.
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When a member joins or leaves a group, applications usually want to run an action. There is a mechanism provided by Tooz to help with the named watchers. It works by caching a list of the members and running the specified callback functions each time a member joins or leaves the group.
To use those callbacks, Tooz provides the watch_join_group and watch_leave_ group methods to register functions to call on join or leave events. If you ever need
to un-register a callback, unwatch_join_group and unwatch_leave_group provide this functionality.
Once the callback functions are registered, they ...