Streaming Replication in PostgreSQL – The Ultimate Guide for DBAs

• Pradip
• 25 Nov, 2024
• 0 Comments
• 3 Mins Read

Streaming Replication in PostgreSQL – The Ultimate Guide for DBAs

Hey, my DBA friends! Whats up?

Let me ask you this: how many times have you had your heart racing, wondering if your database is safe during a failure? Don’t worry; we’ve all been there. 😅

Imagine this scenario, suppose you’re working for a top MNC, and suddenly, the primary server goes down. Panic sets in. But wait, your standby server is already up and running because you set up “streaming replication”. Disaster averted, applause incoming😋👏!

Imagine you’re managing databases for a company like Flipkart. With millions of daily transactions, any downtime could mean a loss of revenue and trust. By setting up streaming replication, Flipkart ensures their operations run smoothly, even during unexpected server failures or maintenance.

Streaming replication isn’t just a technical term; it’s like having a twin for your primary database, ready to take over at a moment’s notice. Whether you’re working with e-commerce giants, banks, or IT service companies, “Streaming replication in PostgreSQL” is your best friend when it comes to keeping databases available and reliable. And the best part? Setting it up is easier than you think! Let me guide you through the process step by step.

What is Streaming Replication?

In simple terms, streaming replication is a process where a “standby server” keeps a live copy of the “primary server’s data” by continuously receiving updates. If the primary server goes down, the standby can quickly take over with minimal downtime.

Here’s why it’s important:

• High availability: Your services keep running even if the primary server crashes.
• Data safety: Data remains protected with real-time backups.
• Scalability: You can use the standby for read-only operations, reducing the load on the primary server.

How to Set Up Streaming Replication in PostgreSQL

Let’s break it down into simple steps:

Step 1: Configure the Primary Server

1. Edit postgresql.conf :

Enable replication settings:

wal_level = replica  
max_wal_senders = 5  
wal_keep_size = 128MB

2. Update pg_hba.conf:

Allow the standby server to connect:

php
host replication replicator <standby_ip>/32 md5

3. Create a replication user:

sql  
CREATE ROLE replicator WITH REPLICATION LOGIN PASSWORD 'replicator_password'; 

4. Restart the PostgreSQL service.

Step 2: Take a Backup of the Primary Server

Use the pg_basebackup tool to copy data from the primary server:

css
pg_basebackup -h <primary_ip> -D /var/lib/postgresql/standby_data -U replicator -Fp -Xs -P 

Step 3: Set Up the Standby Server

1. Copy the postgresql.conf and pg_hba.conf files from the primary server to the standby server.

2. Create a recovery.conf file (or standby.signal for PostgreSQL 12+):

arduino
primary_conninfo = 'host=<primary_ip> port=5432 user=replicator password=replicator_password' 

3. Start the PostgreSQL service on the standby server.

Step 4: Test the Replication

1. Verify replication status on the primary server:

sql  
SELECT * FROM pg_stat_replication;

2. Simulate a failover: Stop the primary and promote the standby:

 pg_ctl promote

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So, guys! This is it🧐!

Streaming replication is one of the most valuable tools in a DBA’s arsenal. It ensures high availability, keeps your data safe, and builds confidence in your system’s reliability.

If you’re a PostgreSQL DBA or aspiring to become one, mastering this concept is a must. So, why wait? Roll up your sleeves, start setting it up, and enjoy the peace of mind that comes with a reliable database system. Your clients (and your boss!) will thank you.

Let me know your thoughts, and feel free to share your own experiences with replication! 😊

Conclusion

At Learnomate Technologies, we specialize in delivering the best training for PostgreSQL and other database technologies. Whether you’re a beginner or looking to advance your skills, our expert-led programs are designed to make you industry-ready.

Want to dive deeper into topics like streaming replication and other PostgreSQL features? Check out our YouTube channel for insightful tutorials: www.youtube.com/@learnomate.

Explore more about our PostgreSQL training program on our website here: https://learnomate.org/training/postgresql-training/.

Don’t forget to connect with me on LinkedIn for regular updates and discussions on trending tech topics: https://www.linkedin.com/in/ankushthavali/.

If reading blogs is your thing, we’ve got you covered. From PostgreSQL to other trending technologies, our blog page is packed with helpful content. Start exploring here: https://learnomate.org/blogs/.

Let’s keep learning and growing together!

Happy Reading!

ANKUSH😎