Usage of pgpool-II and AGE at PostgeSQL
Tags: apacheage, postgres, database, webdev
Published: 2023-03-31 12:43:52


![fight](https://dev-to-uploads.s3.amazonaws.com/uploads/articles/nc2qdfm9pz7wx2e4qhsn.png)


## Why performance is danger?
ALL are seeking for getting their software to be on of the best solutions and making their code's performance as best as possible but you must make sure of what you are using not to lead to be in danger of performance

## Lets learn about pg-pool

## What is it exactly?

**pgpool-II** is a **middleware** that sits between PostgreSQL servers and a PostgreSQL client to increase **scalability** and **availability**.

pgpool-II acts as a proxy for frontend PostgreSQL client applications and distributes incoming client connections among a pool of PostgreSQL database servers. The pool of servers can be composed of Postgres nodes (master and slaves) and/or Postgres partitioned tables (PGPOOL-II 4.1 and up).

## Features
pgpool-II provides the following features:

-    Connection Pooling: This feature enables pgpool-II to reuse existing connections to the PostgreSQL servers, reducing the overhead of creating and deleting connections for every client request.

-    Load Balancing: pgpool-II distributes client connections across the pool of database servers based on predefined load-balancing policies, such as round-robin, least connections, and weighted least connections.

-    Query Caching: pgpool-II can cache frequently executed SELECT queries to reduce the load on the database servers and improve query performance.

-    Database Replication: pgpool-II supports synchronous and asynchronous replication of PostgreSQL servers, enabling the creation of active-active and active-passive clusters.

-    Watchdog: pgpool-II implements a watchdog process that monitors the pool of database servers and automatically promotes a standby server to a new active server in case of failure.

-    Parallel Query: pgpool-II can optimize parallel query execution on the backend servers for SELECT statements that retrieve a large amount of data.

## What is the relation between using AGE and having to take a look at pg-pool?

**Apache AGE** is an **extension** to **PostgreSQL** database that allows you to use graph database functionality with SQL. It is essentially a wrapper around **Postgres** that introduces new data types and functions to allow you to process **graph-like data**.

**pgpool-II**, on the other hand, is a middleware that sits between PostgreSQL servers and a PostgreSQL client to increase **scalability** and **availability**. Its main goal is to provide load balancing and high-availability for your **PostgreSQL cluster**.

While both Apache AGE and pgpool-II have some relation with PostgreSQL, they are quite different in what they do. **Apache AGE adds functionality to PostgreSQL to enable graph database operations**, while **pgpool-II adds load balancing and high-availability features**.

That being said, you can certainly use Apache AGE and pgpool-II together with PostgreSQL **to improve the performance, scalability, and availability of your graph database system**. When working with Apache AGE and pgpool-II together, pgpool-II can help balance the load between the Apache AGE servers to ensure high performance, and also provide high-availability by redirecting queries from failing servers to healthy ones.


## Is it safe to use pg-pool with AGE?
```While pg-pool is caching the select queries and AGE's queries is always executed at the form of select statement will be any conflict here or not?```

pgpool-II does cache SELECT queries to improve performance, but it does not cache other types of queries. Since Apache AGE's queries are executed as SELECT statements, they can be cached by pgpool-II along with other SELECT queries.

However, you should be careful when using both pgpool-II and Apache AGE together, as the caching behavior of pgpool-II may interfere with Apache AGE's query execution.

If Apache AGE's queries are frequently changing, it may not be a good idea to use pgpool-II's caching feature, as it may serve stale data. In this case, it would be better to configure pgpool-II to disable caching for Apache AGE's queries.

On the other hand, if Apache AGE's queries are stable and not changing frequently, you can take advantage of pgpool-II's caching feature to improve performance.

In summary, while pgpool-II can improve performance when used with Apache AGE, you need to be careful when using caching features to avoid conflicts with Apache AGE's query execution.


**Fortunately** Returning to AGE it seems it became compatible 2 weeks ago 
**https://github.com/apache/age/pull/743**

## Who is working on that?
pgpool-II is an open source project that is actively maintained and supported by a community of developers. It is written in C and released under the PostgreSQL License, which is a liberal open source license that permits free use, modification, and distribution of the software.

## References & Resources

- https://github.com/apache/age
- https://age.apache.org/
- https://github.com/apache/age/pull/743
- https://pgpool.net/mediawiki/index.php/Main_Page