docs: Updated postgres source setup (#395)

* Removed optional parameter from wal_sender_timeout in postgres

* added ssl mode for postgres

* added the issue in troubleshooting section

Author: nayanj98

docs/connectors/postgres/index.mdx

@@ -77,7 +77,7 @@ For users who previously set up jobs using the wal2json plugin: [wal2json plugin
 | Replication Slot `required for CDC` | Logical replication slot (pgoutput) that retains WAL segments until read, ensuring consistent CDC.                                                                            | `olake-repl-slot`                                                                                        |
 | Publication `required for CDC`      | Name of the PostgreSQL publication that defines which tables and operations (INSERT, UPDATE, DELETE, TRUNCATE) to replicate. Must exist in the same database as the replication slot and include all tables for CDC capture. | `postgres_pub` |
 | JDBC URL Parameters                 | Extra [JDBC URL parameters](https://jdbc.postgresql.org/documentation/use/) for fine-tuning the connection.                                                                   | `{"connectTimeout":"20"}`                                                                                |
-| SSL Mode                            | SSL configuration for the database connection. Contains details such as the SSL mode.                                                                                         | `disable`                                                                                                |
+| SSL Mode                            | SSL configuration for the database connection. Contains details such as the SSL mode.                                                                                         | <ul> <li>`require`</li> <li>`disable`</li> <li>`verify-ca`</li> <li>`verify-full`</li> </ul>                                                                                                |
 | SSH Config                          | Configure OLake to connect through an SSH tunnel. See [SSH Config details](/docs/understanding/terminologies/olake#1-ssh-configuration) for the list of supported parameters. | <ul> <li>`No Tunnel`</li> <li>`SSH Key Authentication`</li> <li>`SSH Password Authentication`</li> </ul> |
 
 :::warning Important: Unique Replication Slot Required
@@ -120,7 +120,7 @@ An example `source.json` file will look like this:
 | max_threads                          | Maximum number of worker threads the connector can spin up for parallel tasks.                                                                                      | `10`                                                                                                   | Integer                                                          |
 | retry_count                          | Number of times the retry will take place incase of timeout before failing the sync.                                                                                | `3`                                                                                                    | Integer                                                          |
 | jdbc_url_params                      | Extra [JDBC URL parameters](https://jdbc.postgresql.org/documentation/use/) for fine-tuning the connection.                                                         | `{"connectTimeout":"20"}`                                                                              | Object                                                           |
-| ssl                                  | SSL configuration for the database connection. Contains details such as the SSL mode.                                                                               | `{"mode": "disable"}`                                                                                  | Object                                                           |
+| ssl                                  | SSL configuration for the database connection. Contains details such as the SSL mode.                                                                               |  <ul> <li>`require`</li> <li>`disable`</li> <li>`verify-ca`</li> <li>`verify-full`</li> </ul>          | Object                                                           |
 | ssh_config                           | Configure OLake to connect through an SSH tunnel. See [SSH Config details](/docs/understanding/terminologies/olake#1-ssh-configuration) for parameter descriptions. | `{"host": "my-tunnel-host", "port": 22 , "username": "my-tunnel-user", "password": "tunnel-password"}` | Object                                                           |
 
 
@@ -226,6 +226,18 @@ To allow a specific role to bypass RLS entirely, execute the following command (
 ALTER USER <rolename> WITH BYPASSRLS;
 ```
 
+### 3. Failed with non retryable error: LSN not updated after `X` mins
+
+```logs
+Failed with non retryable error: LSN not updated after `X` mins
+```
+
+This issue occurs when `wal_sender_timeout` is set too low (for example, `30s`). If CDC processing takes longer than that, PostgreSQL closes the replication connection before LSN acknowledgment is completed.
+
+It is more likely to happen on databases with concurrent writes or heavier CDC load.
+
+**Solution**: Set `wal_sender_timeout` to `0` (recommended) or a sufficiently large value.
+
 **If the issue is not listed here, post the query on Slack to get it resolved within a few hours.**
 
 ## Changelog

docs/connectors/postgres/setup/aurora.mdx

@@ -29,7 +29,7 @@ Configure these key parameters:
    - **`rds.logical_replication = 1`** - Enables logical replication (required for pgoutput)
    - **`wal_level = logical`** - May be set automatically by the above parameter
    - **`max_wal_senders`** and **`max_replication_slots`** - Set to accommodate your CDC connections
-   - **`wal_sender_timeout = 0`** - *(Optional)* Prevents timeouts during long snapshots
+   - **`wal_sender_timeout = 0`** - Prevents timeouts during long snapshots
 
    Save the changes after configuration.
 

docs/connectors/postgres/setup/azure.mdx

@@ -35,7 +35,7 @@ In the Azure Portal, navigate to your PostgreSQL Flexible Server. Go to `Setting
    | `wal_level` | `logical` | Enable logical replication |
    | `max_replication_slots` | `≥5` | Number of concurrent CDC connections |
    | `max_wal_senders` | `≥7` | Should exceed replication slots |
-   | `wal_sender_timeout` | `0` | *(Optional)* Prevents snapshot timeouts |
+   | `wal_sender_timeout` | `0` | Prevents snapshot timeouts |
 
    ![azure-server-parameters](/img/docs/cdc/postgres/azure-server-parameters.webp)
 

docs/connectors/postgres/setup/generic.mdx

@@ -49,7 +49,7 @@ wal_level = logical
 max_replication_slots = 10
 max_wal_senders = 10
 
-# Optional: Prevent timeouts during long snapshots
+# Prevent timeouts during long snapshots
 wal_sender_timeout = 0
 
 # Optional: Control WAL retention

docs/connectors/postgres/setup/rds.mdx

@@ -32,7 +32,7 @@ In the AWS RDS console, go to `Parameter Groups` and create a new parameter grou
 | `wal_level` | `logical` | Usually set automatically by above |
 | `max_replication_slots` | `≥5` | Number of concurrent CDC connections |
 | `max_wal_senders` | `≥7` | Should exceed replication slots |
-| `wal_sender_timeout` | `0` | *(Optional)* Prevents snapshot timeouts |
+| `wal_sender_timeout` | `0` | Prevents snapshot timeouts |
 
 Save the parameter group changes.