# ETCD

> The distributive consensus storage
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ETCD is a distributed, reliable key-value store for the most critical data of a distributed system.
[**etcd**](https://etcd.io/) is used as [**DCS**](https://patroni.readthedocs.io/en/latest/dcs_failsafe_mode.html) (Distributed configuration storage) for patroni, the PostgreSQL HA Agent for config management and leader election.

In short, [`PGSQL`](/docs/pgsql) depends on a global [`ETCD`](/docs/etcd) module, and ETCD depends on [`NODE`](/docs/node) module to work properly (use the node CA).





**Configuration**


        Define etcd cluster at different size



**Parameters**


        Customize etcd components with 10 parameters



**Administration**


        Adding / Removing etcd members, refresh endpoints...



**Playbooks**


        Ansible playbooks that can be used in etcd module



**Monitoring**


        Dashboards, metrics, record & alerting rules.



**FAQ**


        Frequently Asked Questions about etcd module

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Section pages:

- [Configure](/docs/etcd/config/): describe the cluster you want
- [Parameter](/docs/etcd/param/): Customize etcd with 12 parameters
- [Administration](/docs/etcd/admin/): Manage your etcd cluster
- [Playbook](/docs/etcd/playbook/): control primitives
- [Monitor](/docs/etcd/monitor/): Dashboards and alerting rules for etcd module
- [FAQ](/docs/etcd/faq/): frequently asked questions