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README.md

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+
+# pgedge-patroni: pgEdge's Spock Three AZ Clustering
+
+Patroni is a template for high availability (HA) PostgreSQL solutions using Python. For maximum accessibility, Patroni supports a variety of distributed configuration stores like [ZooKeeper](https://zookeeper.apache.org/), [etcd](https://github.com/coreos/etcd), [Consul](https://github.com/hashicorp/consul) or [Kubernetes](https://kubernetes.io). Database engineers, DBAs, DevOps engineers, and SREs who are looking to quickly deploy HA PostgreSQL in datacenters - or anywhere else - will hopefully find it useful.
+
+Currently pgedge-patroni supported PostgreSQL 15 and above.
+
+![Image Description](pgedge-ultra-high-availability.png)
+
+## How Patroni Works
+
+Patroni originated as a fork of [Governor](https://github.com/compose/governor), the project from Compose. It includes plenty of new features.
+
+For an example of a Docker-based deployment with Patroni, see [Spilo](https://github.com/zalando/spilo), currently in use at Zalando.
+
+For additional background info, see:
+- [Elephants on Automatic: HA Clustered PostgreSQL with Helm](https://www.youtube.com/watch?v=CftcVhFMGSY), talk by Josh Berkus and Oleksii Kliukin at KubeCon Berlin 2017
+- [PostgreSQL HA with Kubernetes and Patroni](https://www.youtube.com/watch?v=iruaCgeG7qs), talk by Josh Berkus at KubeCon 2016 (video)
+- [Feb. 2016 Zalando Tech blog post](https://tech.zalando.de/blog/zalandos-patroni-a-template-for-high-availability-postgresql/)
+
+## Replication Choices
+
+Patroni uses Postgres' streaming replication, which is asynchronous by default. Patroni's asynchronous replication configuration allows for ``maximum_lag_on_failover`` settings. 
+This setting ensures failover will not occur if a follower is more than a certain number of bytes behind the leader. This setting should be increased or decreased based on business requirements. It's also possible to use synchronous replication for better durability guarantees.
+
+See replication modes documentation [here](https://github.com/zalando/patroni/blob/master/docs/replication_modes.rst) for details.
+
+## Applications Should Not Use Superusers
+
+When connecting from an application, always use a non-superuser. Patroni requires access to the database to function properly. By using a superuser from an application, you can potentially use the entire connection pool, including the connections reserved for superusers, with the ``superuser_reserved_connections`` setting. If Patroni cannot access the Primary because the connection pool is full, behavior will be undesirable.