Added Troubleshoot Patroni startup options subsection

Fixed pgbackrest setup

Author: nastena1606

docs/solutions/ha-patroni.md

@@ -302,9 +302,7 @@ Now it's time to start Patroni. You need the following commands on all nodes but
     $ sudo journalctl -fu percona-patroni
     ```
 
-    A common error is Patroni complaining about the lack of proper entries in the `pg_hba.conf` file. If you see such errors, you must manually add or fix the entries in that file and then restart the service.
-
-    Changing the `patroni.yml` file and restarting the service will not have any effect here because the bootstrap section specifies the configuration to apply when PostgreSQL is first started in the node. It will not repeat the process even if the Patroni configuration file is modified and the service is restarted. 
+    See [Troubleshooting Patroni startup](#troubleshooting-patroni-startup) for guidelines in case of errors. 
 
     If Patroni has started properly, you should be able to locally connect to a PostgreSQL node using the following command:
 
@@ -344,4 +342,26 @@ Now it's time to start Patroni. You need the following commands on all nodes but
         | node2  | 10.0.100.2 | Replica | streaming |  1 |         0 |
         | node3  | 10.0.100.3 | Replica | streaming |  1 |         0 |
         +--------+------------+---------+-----------+----+-----------+
-        ```
+        ```
+
+### Troubleshooting Patroni startup
+
+ A common error is Patroni complaining about the lack of proper entries in the `pg_hba.conf` file. If you see such errors, you must manually add or fix the entries in that file and then restart the service.
+
+An example of such an error is `No pg_hba.conf entry for replication connection from host to <IP>, user replicator, no encryption`. This means that Patroni cannot connect to the node you're adding to the cluster. To resolve this issue, add the IP addresses of the nodes to the `pg_hba:` section of the Patroni configuration file. 
+
+```
+pg_hba: # Add following lines to pg_hba.conf after running 'initdb'
+      - host replication replicator 127.0.0.1/32 trust
+      - host replication replicator 0.0.0.0/0 md5
+      - host replication replicator 10.0.100.2/32 trust
+      - host replication replicator 10.0.100.3/32 trust
+      - host all all 0.0.0.0/0 md5
+      - host all all ::0/0 md5
+      recovery_conf:
+            restore_command: cp /home/postgres/archived/%f %p
+```
+
+For production use, we recommend adding nodes individually as the more secure way. However, if your network is secure and you trust it, you can add the whole network these nodes belong to as the trusted one to bypass passwords use during authentication. Then all nodes from this network can connect to Patroni cluster. 
+
+Changing the `patroni.yml` file and restarting the service will not have any effect here because the bootstrap section specifies the configuration to apply when PostgreSQL is first started in the node. It will not repeat the process even if the Patroni configuration file is modified and the service is restarted. 

docs/solutions/pgbackrest.md

@@ -35,7 +35,7 @@ Do the following steps on the `backup` node.
 1. Create environment variables to simplify the config file creation:
 
     ```{.bash data-prompt="$"}
-    export SRV_NAME="bkp-srv"
+    export SRV_NAME="backup"
     export NODE1_NAME="node1"
     export NODE2_NAME="node2"
     export NODE3_NAME="node3"
@@ -56,7 +56,7 @@ Do the following steps on the `backup` node.
 
 3. The default `pgBackRest` configuration file location is `/etc/pgbackrest/pgbackrest.conf`, but some systems continue to use the old path, `/etc/pgbackrest.conf`, which remains a valid alternative. If the former is not present in your system, create the latter.
 
-    Access the file's parent directory (either `cd /etc/` or `cd /etc/pgbackrest/`), and make a backup copy of it:
+    Go to the file's parent directory (either `cd /etc/` or `cd /etc/pgbackrest/`), and make a backup copy of it:
 
     ```{.bash data-prompt="$"}
     $ sudo cp pgbackrest.conf pgbackrest.conf.orig
@@ -92,7 +92,7 @@ Do the following steps on the `backup` node.
         repo1-retention-full=4 
     
         # Server general options
-        process-max=12
+        process-max=4  # This depends on the number of CPU resources your server has. The recommended value should equal or be less than the number of CPUs. While more processes can speed up backups, they will also consume additional system resources.
         log-level-console=info
         #log-level-file=debug
         log-level-file=info
@@ -174,7 +174,7 @@ Do the following steps on the `backup` node.
         repo1-retention-full=4 
     
         # Server general options
-        process-max=12
+        process-max=4  # This depends on the number of CPU resources your server has. The recommended value should equal or be less than the number of CPUs. While more processes can speed up backups, they will also consume additional system resources.
         log-level-console=info
         #log-level-file=debug
         log-level-file=info
@@ -340,7 +340,7 @@ Run the following commands on `node1`, `node2`, and `node3`.
 
     ```{.bash data-prompt="$"}
     $ export NODE_NAME=`hostname -f`
-    $ export SRV_NAME="bkp-srv"
+    $ export SRV_NAME="backup"
     $ export CA_PATH="/etc/ssl/certs/pg_ha"
     ```
     
@@ -379,7 +379,7 @@ Run the following commands on `node1`, `node2`, and `node3`.
         repo1-host-ca-file=${CA_PATH}/ca.crt
     
         # general options
-        process-max=16
+        process-max=6
         log-level-console=info
         log-level-file=debug
     
@@ -409,7 +409,7 @@ Run the following commands on `node1`, `node2`, and `node3`.
         repo1-host-ca-file=${CA_PATH}/ca.crt
     
         # general options
-        process-max=16
+        process-max=6
         log-level-console=info
         log-level-file=debug
     
@@ -508,7 +508,7 @@ Run the following commands on `node1`, `node2`, and `node3`.
 11. Reload the changed configurations. Provide the cluster name or the node name for the following command. In our example we use the `cluster_1` cluster name:
 
     ```{.bash data-prompt="$"}
-    $ patronictl -c /etc/patroni/patroni.yml reload cluster_1
+    $ patronictl -c /etc/patroni/patroni.yml restart cluster_1
     ```
 
     It may take a while to reload the new configuration.