Primary purpose of the IConnectionPool is to manage RabbitMQ Connections that are each wrapped inside a class called IConnectionHost. This is just to track the Connection and it's various states. This is primarily achieved by subscribing to the EventHandlers. You would want to use these yourself in your own integration very similarly to the IConnectionHost.

Json -> RabbitOptions -> ConnectionPool  
ConnectionPool .ctor -> ConnectionFactory -> Create RabbitMQ Connections

The ConnectionPool is pretty bare bones. The reason for that is, that RabbitMQ does most of it's heavy lifting with a RabbitMQ channel. This is called a IModel. We will cover that in the ChannelPool guide. For now, we need a connection to build a channel.

For now here is the IConnectionPool interface:

public interface IConnectionPool
{
    RabbitOptions Options { get; }

    IConnection CreateConnection(string connectionName);
    ValueTask<IConnectionHost> GetConnectionAsync();
    ValueTask ReturnConnectionAsync(IConnectionHost connHost);

    Task ShutdownAsync();
}

Here is some a simple ConnectionPool setup and basic usage.

It really helps to have RabbitOptions already setup and ready to go. I will use this as a file named SampleRabbitOptions.json:

{
  "PoolOptions": {
    "Uri": "amqp://guest:guest@localhost:5672/",
    "MaxChannelsPerConnection": 2000,
    "HeartbeatInterval": 6,
    "AutoRecovery": true,
    "TopologyRecovery": true,
    "NetRecoveryTimeout": 5,
    "ContinuationTimeout": 10,
    "EnableDispatchConsumersAsync": true
    "ServiceName": "HoC.RabbitMQ",
    "Connections": 2,
    "Channels": 0,
    "AckableChannels": 0,
    "SleepOnErrorInterval": 1000,
    "TansientChannelStartRange": 10000,
    "UseTransientChannels": false
  }
}

I generally always have AutoRecovery and TopologyRecovery set to true.

The factory options are to assist with setting up the RabbitMQ.Client and the IConnectionFactory. You can find additional details on IConnectionFactory here.

I will use a helper method to load the RabbitOptions from the file.

using HouseofCat.RabbitMQ.Pools;
using HouseofCat.Utilities;

var rabbitOptions = await JsonFileReader.ReadFileAsync<RabbitOptions>("SampleRabbitOptions.json");
var pool = new ConnectionPool(rabbitOptions);

Per the config above you will see that we should have 2 connections. Here's how you get one!

using HouseofCat.RabbitMQ;
using HouseofCat.RabbitMQ.Pools;
using HouseofCat.Utilities;

var rabbitOptions = await JsonFileReader.ReadFileAsync<RabbitOptions>("SampleRabbitOptions.json");
var pool = new ConnectionPool(rabbitOptions);

var connectionHost = await pool.GetConnectionAsync();

// Create a Channel for communication using a RabbitMQ Connection.
var channel = connectionHost.Connection.CreateModel();

// When you are done with the `Connection` you can return it to the pool.
await pool.ReturnConnectionAsync(connectionHost);

If you prefer to use the ConnectionPool directly just to create Connections on demand you can do this manually.

CreateConnection example:

var connectionHost = pool.CreateConnection();