PG-955 Added etcd.service sample file (#638)

PG-963 Updated Patroni config

docs/enable-extensions.md

@@ -10,20 +10,43 @@ While setting up a high availability PostgreSQL cluster with Patroni, you will n
 
 - Patroni installed on every ``postresql`` node. 
 
-- Distributed Configuration Store (DCS). Patroni supports such DCSs as etcd, zookeeper, Kubernetes though [etcd](https://etcd.io/) is the most popular one. It is available within Percona Distribution for PostgreSQL for all supported operating systems.
+- Distributed Configuration Store (DCS). Patroni supports such DCSs as etcd, zookeeper, Kubernetes though [etcd](https://etcd.io/) is the most popular one. It is available within Percona Distribution for PostgreSQL for all supported operating systems. 
 
 - [HAProxy :octicons-link-external-16:](http://www.haproxy.org/).
 
+If you install the software fom packages, all required dependencies and service unit files are included. If you [install the software from the tarballs](tarball.md), you must first enable `etcd`. See the steps in the [etcd](#etcd) section if this document.
+
 See the configuration guidelines for [Debian and Ubuntu](solutions/ha-setup-apt.md) and [RHEL and CentOS](solutions/ha-setup-yum.md). 
 
-!!! important
+## etcd
+
+The following steps apply if you [installed etcd  from the tarballs](tarball.md).
 
-    To configure high-availability with [the software installed from the tarballs](tarball.md), install the Python client for `etcd` to resolve dependency issues. Use the following command:
+1. Install the Python client for `etcd` to resolve dependency issues. Use the following command:
 
     ```{.bash data-prompt="$"}
     $ /opt/percona-python3/bin/pip3 install python-etcd
     ```
-
+
+2. Create the `etcd.service` file. This file allows `systemd` to start, stop, restart, and manage the `etcd` service. This includes handling dependencies, monitoring the service, and ensuring it runs as expected. 
+
+    ```ini title="/etc/systemd/system/etcd.service"
+    [Unit]
+    After=network.target
+    Description=etcd - highly-available key value store
+
+    [Service]
+    LimitNOFILE=65536
+    Restart=on-failure
+    Type=notify
+    ExecStart=/usr/bin/etcd --config-file /etc/etcd/etcd.conf.yaml
+    User=etcd
+
+    [Install]
+    WantedBy=multi-user.target
+    ```
+
+
 
 ## pgBadger
 

docs/solutions/ha-setup-apt.md

@@ -127,6 +127,8 @@ The distributed configuration store provides a reliable way to store data that n
 
 This document provides configuration for etcd version 3.5.x. For how to configure etcd cluster with earlier versions of etcd, read the blog post by _Fernando Laudares Camargos_ and _Jobin Augustine_ [PostgreSQL HA with Patroni: Your Turn to Test Failure Scenarios](https://www.percona.com/blog/postgresql-ha-with-patroni-your-turn-to-test-failure-scenarios/)
 
+If you [installed the software from tarballs](../tarball.md), check how you [enable etcd](../enable-extensions.md#etcd).
+
 The `etcd` cluster is first started in one node and then the subsequent nodes are added to the first node using the `add `command. 
 
 !!! note
@@ -326,6 +328,10 @@ Run the following commands on all nodes. You can do this in parallel:
                   max_replication_slots: 10
                   wal_log_hints: "on"
                   logging_collector: 'on'
+                  max_wal_size: '10GB'
+                  archive_mode: "on"
+                  archive_timeout: 600s
+                  archive_command: "cp -f %p /home/postgres/archived/%f"
 
       # some desired options for 'initdb'
       initdb: # Note: It needs to be a list (some options need values, others are switches)
@@ -357,7 +363,7 @@ Run the following commands on all nodes. You can do this in parallel:
         connect_address: ${NODE_IP}:5432
         data_dir: ${DATA_DIR}
         bin_dir: ${PG_BIN_DIR}
-        pgpass: /tmp/pgpass
+        pgpass: /tmp/pgpass0
         authentication:
             replication:
                 username: replicator

docs/solutions/ha-setup-yum.md

@@ -118,7 +118,9 @@ It's not necessary to have name resolution, but it makes the whole setup more re
 
 The distributed configuration store provides a reliable way to store data that needs to be accessed by large scale distributed systems. The most popular implementation of the distributed configuration store is etcd. etcd is deployed as a cluster for fault-tolerance and requires an odd number of members (n/2+1) to agree on updates to the cluster state. An etcd cluster helps establish a consensus among nodes during a failover and manages the configuration for the three PostgreSQL instances.
 
-This document provides configuration for etcd version 3.5.x. For how to configure etcd cluster with earlier versions of etcd, read the blog post by _Fernando Laudares Camargos_ and _Jobin Augustine_ [PostgreSQL HA with Patroni: Your Turn to Test Failure Scenarios](https://www.percona.com/blog/postgresql-ha-with-patroni-your-turn-to-test-failure-scenarios/)
+This document provides configuration for etcd version 3.5.x. For how to configure etcd cluster with earlier versions of etcd, read the blog post by _Fernando Laudares Camargos_ and _Jobin Augustine_ [PostgreSQL HA with Patroni: Your Turn to Test Failure Scenarios](https://www.percona.com/blog/postgresql-ha-with-patroni-your-turn-to-test-failure-scenarios/).
+
+If you [installed the software from tarballs](../tarball.md), check how you [enable etcd](../enable-extensions.md#etcd).
 
 The `etcd` cluster is first started in one node and then the subsequent nodes are added to the first node using the `add `command. 
 
@@ -321,9 +323,6 @@ Run the following commands on all nodes. You can do this in parallel:
           loop_wait: 10
           retry_timeout: 10
           maximum_lag_on_failover: 1048576
-          slots:
-              percona_cluster_1:
-                type: physical
 
           postgresql:
               use_pg_rewind: true
@@ -336,6 +335,10 @@ Run the following commands on all nodes. You can do this in parallel:
                   max_replication_slots: 10
                   wal_log_hints: "on"
                   logging_collector: 'on'
+                  max_wal_size: '10GB'
+                  archive_mode: "on"
+                  archive_timeout: 600s
+                  archive_command: "cp -f %p /home/postgres/archived/%f"
 
       # some desired options for 'initdb'
       initdb: # Note: It needs to be a list (some options need values, others are switches)
@@ -367,7 +370,7 @@ Run the following commands on all nodes. You can do this in parallel:
         connect_address: ${NODE_IP}:5432
         data_dir: ${DATA_DIR}
         bin_dir: ${PG_BIN_DIR}
-        pgpass: /tmp/pgpass
+        pgpass: /tmp/pgpass0
         authentication:
             replication:
                 username: replicator