Storage Data Providers

Relevant source files

• .gitignore
• CODE_COVERAGE.md
• src/Audit.DynamicProxy/Audit.DynamicProxy.csproj
• src/Audit.EntityFramework.Core/Audit.EntityFramework.Core.csproj
• src/Audit.EntityFramework/Audit.EntityFramework.csproj
• src/Audit.Mvc/Audit.Mvc.csproj
• src/Audit.NET.MongoDB/Audit.NET.MongoDB.csproj
• src/Audit.NET.MySql/Audit.NET.MySql.csproj
• src/Audit.NET.RavenDB/Providers/RavenDbDataProvider.cs
• src/Audit.NET.Redis/Audit.NET.Redis.csproj
• src/Audit.NET.SqlServer/Audit.NET.SqlServer.csproj
• src/Audit.NET.Udp/Audit.NET.Udp.csproj
• src/Audit.NET/Audit.NET.csproj
• src/Audit.WCF/Audit.WCF.csproj
• src/Audit.WebApi/Audit.WebApi.csproj
• test/Audit.AzureEventHubs.UnitTest/AzureEventHubsTests.cs
• test/Audit.AzureStorageTables.UnitTest/AzureTableDataProviderIntegrationTests.cs
• test/Audit.RavenDB.UnitTest/RavenDbDataProviderTests.cs
• test/Audit.Redis.UnitTest/RedisTests.cs
• test/AzureSettings.cs

Audit.NET is designed with a pluggable architecture that separates the collection of audit data from its storage. While the core library includes several built-in providers (such as File, EventLog, and InMemory), the majority of storage integrations are provided via external NuGet packages. These providers allow you to persist AuditEvent objects to various relational databases, NoSQL document stores, cloud storage services, and messaging systems.

Common Implementation Pattern

Most external storage providers follow a consistent implementation pattern to ensure ease of use and predictability:

1. Fluent Configuration: Providers extend the IAuditConfigurator to provide a domain-specific fluent API within Configuration.Setup().
2. Core Operations: They implement the AuditDataProvider base class src/Audit.NET/Providers/AuditDataProvider.cs7 or the IAuditDataProvider interface, overriding InsertEvent, ReplaceEvent, and where applicable, GetEvent.
3. Async Support: Providers implement asynchronous versions of the core operations (e.g., InsertEventAsync) to support non-blocking I/O src/Audit.NET.RavenDB/Providers/RavenDbDataProvider.cs112-121
4. JSON Serialization: Most providers serialize the AuditEvent into JSON using the configured IJsonAdapter (System.Text.Json or Newtonsoft.Json) before storage src/Audit.NET.RavenDB/Providers/RavenDbDataProvider.cs87-93

Data Provider Interaction

The following diagram illustrates how the AuditScope interacts with different categories of data providers during the audit lifecycle.

Audit Data Provider Flow

Sources: src/Audit.NET/Audit.NET.csproj1-54 CODE_COVERAGE.md25

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Relational Database Providers

These providers are used for storing audit trails in traditional SQL databases. They typically support a "Hybrid" storage approach: storing the entire audit event as a JSON blob in one column, while extracting specific metadata into dedicated relational columns via CustomColumns.

• SQL Server: Utilizes SqlDataProvider provided by the Audit.NET.SqlServer package src/Audit.NET.SqlServer/Audit.NET.SqlServer.csproj16
• PostgreSQL: Utilizes PostgreSqlDataProvider for flexible JSONB storage.
• MySQL: Utilizes MySqlDataProvider via the Audit.NET.MySql package src/Audit.NET.MySql/Audit.NET.MySql.csproj16

For details on schema setup and column mapping, see Relational Database Providers.

NoSQL & Document Database Providers

NoSQL providers are ideal for audit trails because AuditEvent objects are naturally hierarchical and schema-less.

• MongoDB: Uses MongoDataProvider to store events as BSON documents. It includes logic to handle BSON element naming constraints via FixDocumentElementNames CODE_COVERAGE.md25
• Azure Cosmos DB: The AzureCosmosDataProvider supports the latest Azure Cosmos DB client.
• RavenDB: Uses RavenDbDataProvider which can be configured with a custom IDocumentStore src/Audit.NET.RavenDB/Providers/RavenDbDataProvider.cs33-45
• Elasticsearch & OpenSearch: High-performance providers for indexing audit data.
• Amazon DynamoDB: Provides storage via the DynamoDataProvider.

For details on document mapping and querying, see NoSQL & Document Database Providers.

Azure Cloud Storage Providers

These providers leverage Azure's managed storage services for scalability and durability.

• Azure Blob Storage: Stores events as individual JSON blobs.
• Azure Table Storage: Uses AzureTableDataProvider to translate audit events into TableEntity rows test/Audit.AzureStorageTables.UnitTest/AzureTableDataProviderIntegrationTests.cs23-29
• Azure Event Hubs: A streaming provider for high-volume audit event ingestion using AzureEventHubsDataProvider test/Audit.AzureEventHubs.UnitTest/AzureEventHubsTests.cs119-125

For details on Azure-specific configuration, see Azure Cloud Storage Providers.

Messaging & Streaming Providers

Messaging providers allow for asynchronous, decoupled processing of audit events.

• Redis: Supports multiple storage modes via RedisDataProvider, including AsString, AsList, AsHash, AsSortedSet, AsPubSub, and AsStream test/Audit.Redis.UnitTest/RedisTests.cs28-33
• Apache Kafka: Publishes events to Kafka topics via KafkaDataProvider.
• UDP: Sends events as connectionless datagrams via UdpDataProvider src/Audit.NET.Udp/Audit.NET.Udp.csproj4-6
• System.Threading.Channels: Provides an in-memory producer/consumer buffer using ChannelDataProvider.

For details on transport modes and messaging patterns, see Messaging & Streaming Providers.

Logging Framework Providers

These providers bridge Audit.NET with existing application logging infrastructure.

• Serilog, NLog, and log4net: Standard integrations that map audit events to structured log entries.
• Windows Event Log: Persists events to the OS event log via EventLogDataProvider CODE_COVERAGE.md25

For details on log formatting and deserialization, see Logging Framework Providers.

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Code Entity Mapping

The following diagram maps logical storage categories to the specific primary data provider classes and their respective project namespaces.

Provider Class Mapping

Sources: src/Audit.NET/Audit.NET.csproj26 src/Audit.NET.SqlServer/Audit.NET.SqlServer.csproj26 src/Audit.NET.MongoDB/Audit.NET.MongoDB.csproj22 src/Audit.NET.Redis/Audit.NET.Redis.csproj26 CODE_COVERAGE.md25