Kafka- Using Avro as serialization format in C#

To help you with using Avro as the serialization format for your Kafka messages, a .NET core global tool avrogen is available.

• First install the tool using dotnet tool install:

dotnet tool install -g Confluent.Apache.Avro.AvroGen

view raw avrogeninstall.cmd hosted with ❤ by GitHub
• Next step is to specify your message schema. Therefore you need to create an .avsc file and add your message specification:

	{
	"namespace": "MessageTypes",
	"type": "record",
	"doc": "A simple message type.",
	"name": "PageViewEvent",
	"fields": [
	{
	"name": "timestamp",
	"type": ["null","string"]
	},
	{
	"name": "ipAddress",
	"type": ["null","string"]
	},
	{
	"name": "sessionId",
	"type": ["null","string"]
	},
	{
	"name": "pageUrl",
	"type": "string"
	},
	{
	"name": "referrer",
	"type": ["null","string"]
	},
	{
	"name": "browser",
	"type": ["null","string"]
	}
	]
	}

view raw PageViewEvent.avsc hosted with ❤ by GitHub
• Now it’s time to generate the necessary code:

avrogen -s PageViewEvent.avsc .

view raw avrogen.cmd hosted with ❤ by GitHub
• This will generate the following:

	// ------------------------------------------------------------------------------
	// <auto-generated>
	// Generated by avrogen, version 1.7.7.5
	// Changes to this file may cause incorrect behavior and will be lost if code
	// is regenerated
	// </auto-generated>
	// ------------------------------------------------------------------------------
	namespace MessageTypes
	{
	using System;
	using System.Collections.Generic;
	using System.Text;
	using global::Avro;
	using global::Avro.Specific;
	public partial class PageViewEvent : ISpecificRecord
	{
	public static Schema _SCHEMA = Schema.Parse(@"{""type"":""record"",""name"":""PageViewEvent"",""namespace"":""MessageTypes"",""fields"":[{""name"":""timestamp"",""type"":[""null"",""string""]},{""name"":""ipAddress"",""type"":[""null"",""string""]},{""name"":""sessionId"",""type"":[""null"",""string""]},{""name"":""pageUrl"",""type"":""string""},{""name"":""referrer"",""type"":[""null"",""string""]},{""name"":""browser"",""type"":[""null"",""string""]}]}");
	private string _timestamp;
	private string _ipAddress;
	private string _sessionId;
	private string _pageUrl;
	private string _referrer;
	private string _browser;
	public virtual Schema Schema
	{
	get
	{
	return PageViewEvent._SCHEMA;
	}
	}
	public string timestamp
	{
	get
	{
	return this._timestamp;
	}
	set
	{
	this._timestamp = value;
	}
	}
	public string ipAddress
	{
	get
	{
	return this._ipAddress;
	}
	set
	{
	this._ipAddress = value;
	}
	}
	public string sessionId
	{
	get
	{
	return this._sessionId;
	}
	set
	{
	this._sessionId = value;
	}
	}
	public string pageUrl
	{
	get
	{
	return this._pageUrl;
	}
	set
	{
	this._pageUrl = value;
	}
	}
	public string referrer
	{
	get
	{
	return this._referrer;
	}
	set
	{
	this._referrer = value;
	}
	}
	public string browser
	{
	get
	{
	return this._browser;
	}
	set
	{
	this._browser = value;
	}
	}
	public virtual object Get(int fieldPos)
	{
	switch (fieldPos)
	{
	case 0: return this.timestamp;
	case 1: return this.ipAddress;
	case 2: return this.sessionId;
	case 3: return this.pageUrl;
	case 4: return this.referrer;
	case 5: return this.browser;
	default: throw new AvroRuntimeException("Bad index " + fieldPos + " in Get()");
	};
	}
	public virtual void Put(int fieldPos, object fieldValue)
	{
	switch (fieldPos)
	{
	case 0: this.timestamp = (System.String)fieldValue; break;
	case 1: this.ipAddress = (System.String)fieldValue; break;
	case 2: this.sessionId = (System.String)fieldValue; break;
	case 3: this.pageUrl = (System.String)fieldValue; break;
	case 4: this.referrer = (System.String)fieldValue; break;
	case 5: this.browser = (System.String)fieldValue; break;
	default: throw new AvroRuntimeException("Bad index " + fieldPos + " in Put()");
	};
	}
	}
	}

view raw PageViewEvent.cs hosted with ❤ by GitHub

The generated type can than be used by your Producer and Consumer logic.

More information: https://www.confluent.io/blog/avro-kafka-data/