---
title: "Failing Over and Failing Back PostgreSQL Streaming Replication"
slug: "failing-over-and-failing-back-postgresql-streaming-replication-3"
tags: ["8.2", "Portal"]
updated: 2025-12-21T06:53:59Z
published: 2025-12-21T06:53:59Z
canonical: "kb.ctera.com/failing-over-and-failing-back-postgresql-streaming-replication-3"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://kb.ctera.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Failing Over and Failing Back PostgreSQL Streaming Replication

## Failing Over to the Secondary Database Server

The secondary database acts as a passive database, meaning it can only process read requests. In the event that the primary database fails, you have to fail over to the secondary database server, making it active, in order to assure proper continuity of the platform.

**Note**

You can also switch between the primary and secondary database servers, making the secondary database server the primary database server and the primary database server a secondary server, when the primary database server is still up.

**To failover to the secondary server:**

1. Using SSH, log in as `root` to the CTERA Portal secondary database server.
2. In the command line, enter the following command: `portal-failover.sh become_master`

The primary database server becomes the secondary server, and the secondary database server becomes the primary server.

## Failing Back to the Primary Database Server

When the original primary server comes back online you can failback to it, to return to the original configuration. ​ To prevent both database servers being identified as the primary database server, triggering inconsistencies in the databases, before you can return the original primary server to being the primary server, you must first define it as a replication, secondary, database. ​ **To failback to the primary database server:**

1. When the former primary database server is running again, using SSH, log in as `root` to the original primary database server.
2. Edit the `/etc/ctera/portal.cfg` file by changing the value of `CTERA_DB_ADDR` to be the new IP address of the original primary database server.
3. In the command line, enter the following command: `portal-failover.sh become_replica`
4. Wait for the script to finish so that the original primary database is recognized as the secondary database.
5. Log in to the portal as a global administrator and In the global administration view, select **Main > Servers** in the navigation pane and click the replication server name.
6. Click **DB Replication** in the server window that is displayed and under **Database Replication** verify that the **Status** value is set to **OK**.

**Note**

If there is a mismatch between the requested WAL files and their location on the server the **Status** value can be set to **Failed** until the mismatch is resolved when the WAL file position reaches the location, which can take a few hours. CTERA recommends the following manual procedure to resolve this issue:

  1. Log in to the portal as a global administrator and In the global administration view, select **Main > Servers** in the navigation pane.  

The **Servers** page is displayed, listing all the servers for the CTERA Portal.
  2. Click the replication server name and in the server window that is displayed, under **General Settings**, uncheck **Replication of**.
  3. Click **Save**.
  4. Click the replication server name again and in the server window that is displayed, under **General Settings**, recheck **Replication of**.
  5. Click **Save**.

The replication process will reinitialize which can be monitored by clicking **DB Replication** in the server window and under **Database replication** verify that the **Status** value is set to **Reinitializing**. After the replication has reinitialized, which can take some time, depending on the portal size and the amount of data to be replicated, and the **Status** value is set to **OK**.
7. Only after the **Status** is set to **OK**, in the command line, enter the following command: `portal-failover.sh become_master`