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Many organizations are frustrated with Solr Cloud deployments due to the perceived cost of managing a separate, dedicated Apache ZooKeeper ensemble. We can ameliorate this complexity by running our own embedded Zookeeper ensemble, based on on

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Compatibility, Deprecation, and Migration Plan

Existing users will be able to continue to run Solr Cloud with an external ZooKeeper quorum.

Major Risks

Zookeeper services launched this way may be subject to Solr availability - if the server is exhausted from too many queries or bad queries then that may adversely impact the health of the whole cluster rather than causing isolated failure on given replicas. This should be mitigated by offering multiple ZK services in a quorum that can tolerate individual node failure, but may be enough motivation to use a larger default quorum size of 5 or 7 members instead of the minimal 3 node setup.

Security considerations

When running our own ZK services, the security of ZK becomes our responsibility instead of being something that we can delegate. The ZK Servers that we start should be secure by default using available authentication methods and practices.

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