# Parameter > Customize etcd with 12 parameters --- There are **12** parameters about the `ETCD` module. `ETCD`: 9 Parameters: | Parameter | Type | Level | Comment | |-------------------------------------------------------|:------:|:-----:|----------------------------------------------| | [`etcd_seq`](#etcd_seq) | int | I | etcd instance identifier, REQUIRED | | [`etcd_cluster`](#etcd_cluster) | string | C | etcd cluster & group name, etcd by default | | [`etcd_learner`](#etcd_learner) | bool | I | prevent purging running etcd instance? | | [`etcd_data`](#etcd_data) | path | C | etcd data directory, /data/etcd by default | | [`etcd_port`](#etcd_port) | port | C | etcd client port, 2379 by default | | [`etcd_peer_port`](#etcd_peer_port) | port | C | etcd peer port, 2380 by default | | [`etcd_init`](#etcd_init) | enum | C | etcd initial cluster state, new or existing | | [`etcd_election_timeout`](#etcd_election_timeout) | int | C | etcd election timeout, 1000ms by default | | [`etcd_heartbeat_interval`](#etcd_heartbeat_interval) | int | C | etcd heartbeat interval, 100ms by default | `ETCD_REMOVE`: 3 Parameters: | Parameter | Type | Level | Comment | |-------------------------------------|:----:|:-----:|----------------------------------------------------------| | [`etcd_safeguard`](#etcd_safeguard) | bool | G/C/A | prevent purging running etcd instance? | | [`etcd_rm_data`](#etcd_rm_data) | bool | G/C/A | remove etcd data during removal? (default: true) | | [`etcd_rm_pkg`](#etcd_rm_pkg) | bool | G/C/A | uninstall etcd packages during removal? (default: false) | ------ ## Defaults The default parameters are defined in [`roles/etcd/defaults/main.yml`](https://github.com/pgsty/pigsty/blob/v3.7.0/roles/etcd/defaults/main.yml) Additional removal parameters are defined in [`roles/etcd_remove/defaults/main.yml`](https://github.com/pgsty/pigsty/blob/v3.7.0/roles/etcd_remove/defaults/main.yml) ```yaml #----------------------------------------------------------------- # ETCD #----------------------------------------------------------------- #etcd_seq: 1 # etcd instance identifier, explicitly required etcd_cluster: etcd # etcd cluster & group name, etcd by default etcd_data: /data/etcd # etcd data directory, /data/etcd by default etcd_learner: false # etcd instance run as learner? false by default etcd_port: 2379 # etcd client port, 2379 by default etcd_peer_port: 2380 # etcd peer port, 2380 by default etcd_init: new # etcd initial cluster state, new or existing etcd_election_timeout: 1000 # etcd election timeout, 1000ms by default etcd_heartbeat_interval: 100 # etcd heartbeat interval, 100ms by default ``` **ETCD_REMOVE Parameters** ```yaml #----------------------------------------------------------------- # ETCD_REMOVE #----------------------------------------------------------------- etcd_safeguard: false # prevent accidental removal? etcd_rm_data: true # remove etcd data during removal? etcd_rm_pkg: false # uninstall etcd packages during removal? ``` ------ ## `etcd_seq` name: `etcd_seq`, type: `int`, level: `I` etcd instance identifier, REQUIRED no default value, you have to specify it explicitly. Here is a 3-node etcd cluster example: ```yaml etcd: # dcs service for postgres/patroni ha consensus hosts: # 1 node for testing, 3 or 5 for production 10.10.10.10: { etcd_seq: 1 } # etcd_seq required 10.10.10.11: { etcd_seq: 2 } # assign from 1 ~ n 10.10.10.12: { etcd_seq: 3 } # use odd numbers vars: # cluster level parameter override roles/etcd etcd_cluster: etcd # mark etcd cluster name etcd etcd_safeguard: false # safeguard against purging ``` ------ ## `etcd_cluster` name: `etcd_cluster`, type: `string`, level: `C` etcd cluster & group name, etcd by default default values: `etcd`, which is a fixed group name, can be useful when you want to use deployed some extra etcd clusters ------ ## `etcd_learner` name: `etcd_learner`, type: `bool`, level: `I` Init etcd instance as learner? default value is `false` When set to `true`, the etcd instance will be init as leaner, so it will not be able to vote in the etcd cluster. You can promote it to a full member later with `etcdctl member promote` command. ------ ## `etcd_data` name: `etcd_data`, type: `path`, level: `C` etcd data directory, `/data/etcd` by default ------ ## `etcd_port` name: `etcd_port`, type: `port`, level: `C` etcd client port, `2379` by default ------ ## `etcd_peer_port` name: `etcd_peer_port`, type: `port`, level: `C` etcd peer port, `2380` by default ------ ## `etcd_init` name: `etcd_init`, type: `enum`, level: `C` etcd initial cluster state, `new` or `existing` default values: `new`, which will create a standalone new etcd cluster. The value `existing` is used when trying to [**append new member**](/docs/etcd/admin/#append-member) to existing etcd cluster. ------ ## `etcd_election_timeout` name: `etcd_election_timeout`, type: `int`, level: `C` etcd election timeout, `1000` (ms) by default ------ ## `etcd_heartbeat_interval` name: `etcd_heartbeat_interval`, type: `int`, level: `C` etcd heartbeat interval, `100` (ms) by default ------ ## `ETCD_REMOVE` This section contains parameters for the [`etcd_remove`](https://github.com/pgsty/pigsty/blob/v3.7.0/roles/etcd_remove/defaults/main.yml) role, which are action flags for the [`etcd-rm.yml`](/docs/etcd/playbook/#etcd-rmyml) playbook. ------ ### `etcd_safeguard` name: `etcd_safeguard`, type: `bool`, level: `G/C/A` prevent purging etcd instance? default value is `false` If enabled, running etcd instance will not be purged by [`etcd-rm.yml`](/docs/etcd/playbook/#etcd-rmyml) playbook. ------ ### `etcd_rm_data` name: `etcd_rm_data`, type: `bool`, level: `G/C/A` remove etcd data during removal? default value is `true` When enabled, the [`etcd-rm.yml`](/docs/etcd/playbook/#etcd-rmyml) playbook will remove etcd data directories and configuration files during cluster or member removal. ------ ### `etcd_rm_pkg` name: `etcd_rm_pkg`, type: `bool`, level: `G/C/A` uninstall etcd packages during removal? default value is `false` When enabled, the [`etcd-rm.yml`](/docs/etcd/playbook/#etcd-rmyml) playbook will uninstall etcd packages during cluster or member removal.