E.g. if we quote ZooKeeper:
> ZooKeeper is a centralized service for maintaining configuration information, naming, providing distributed synchronization, and providing group services.
and ClickHouse
> ClickHouse is the fastest and most resource-efficient open-source database for real-time applications and analytics.
Like this are completely different use cases with just a small overlap.
> ClickHouse Keeper is a drop-in replacement for ZooKeeper
That opening was about ClickHouse in general, but the article is about one particular application using the database.
Generally, ClickHouse Keeper provides the coordination system for data replication and distributed DDL query execution for ClickHouse clusters.
and now knowing more about it I would say the answer to my question is a clear yes, it used ZK for something ZK wasn't at all intended for
which means it makes a lot of sense that they replace it
yes I confused the quotes
but the question in general about weather ClickHouse Keeper and ZooKeeper are designed for completely different use-cases which happen to be similar and can work with the same interface still stands
and by now knowing more then my original comment I would answer the question with yes