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> Built-in replication without the need to run Zookeeper, with multi-tier sharding support. They rewrite the ZK protocol using multi-paxos within CH itself. It'
by dunkelheit 5y ago
> Built-in replication without the need to run Zookeeper, with multi-tier sharding support. They rewrite the ZK protocol using multi-paxos within CH itself. It's great.
AFAIK this description is kind of misleading. When they say that they got rid of Zookeeper people expect that they can just connect clickhouse nodes to each other and the replication will work. But that is not how things work - you still have to run external service called clickhouse-keeper. Basically what they did is they rewrote Zookeeper in C++.
- mr-karan 5y agoFwiw, Clickhouse Keeper _can_ be run as an external daemon if you wish so. But it's packaged with the server binary itself, so once you add <keeper_config> to all your server nodes, you're good to go, without running anything else.
- tonyhb 5y agoYou can run clickhouse-keeper embedded in the server, though. That way, each "primary" handles incoming SQL connections _and_ paxos communication without additional infra.