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Logging

StackExchange.Redis.Extensions uses source-generated logging via [LoggerMessage] attributes for zero-allocation, high-performance log output. All logs are emitted through Microsoft.Extensions.Logging.ILogger.

Setup

Logging is automatic when using ASP.NET Core DI — just ensure your RedisConfiguration.LoggerFactory is set (done automatically by AddStackExchangeRedisExtensions).

For manual setup:

var config = new RedisConfiguration
{
    LoggerFactory = LoggerFactory.Create(builder => builder.AddConsole()),
    // ... other config
};

Log Events Reference

All log messages have a stable EventId for filtering and alerting.

Connection Pool (1xxx)

EventId Level Message When
1001 Information Redis connection pool initialized: {PoolSize} connections to {Endpoint} in {ElapsedMs}ms Pool created successfully at startup
1002 Debug Using connection {ConnectionHash} with {Outstanding} outstanding commands Every GetConnection() call
1003 Warning All Redis connections are disconnected. Using connection {ConnectionHash} in degraded mode All pool connections are down
1004 Debug Disposing Redis connection pool ({PoolSize} connections) Pool is being disposed
1005 Information Using async ConfigurationOptions handler for pool initialization Azure Managed Identity or custom handler active
1006 Error Redis pool initialization failed at connection {Index} of {PoolSize}. Cleaning up {CreatedConnections} previously created connections Connection fails during pool creation

Connection State (2xxx)

EventId Level Message When
2001 Error Redis connection failed: {FailureType} StackExchange.Redis ConnectionFailed event
2002 Warning Redis connection restored to {Endpoint} StackExchange.Redis ConnectionRestored event
2003 Error Redis internal error from {Origin} StackExchange.Redis InternalError event
2004 Error Redis server error: {ErrorMessage} StackExchange.Redis ErrorMessage event

Client Factory (3xxx)

EventId Level Message When
3001 Information Redis client created: {ClientName} (database: {Database}) Each named client registered

Pub/Sub (4xxx)

EventId Level Message When
4001 Error Error processing subscription message on channel {Channel} Subscription handler throws an exception

Recommended Log Levels

Environment Minimum Level What you see
Production Warning Disconnections, degraded mode, handler errors
Staging Information Pool init, client creation, Azure handler usage
Development Debug Every connection selection, pool disposal

Filtering

Use the StackExchange.Redis.Extensions.Core category to control log output:

{
  "Logging": {
    "LogLevel": {
      "Default": "Warning",
      "StackExchange.Redis.Extensions.Core": "Information"
    }
  }
}

Interpreting Common Log Patterns

Healthy startup

info: StackExchange.Redis.Extensions.Core[1001] Redis connection pool initialized: 5 connections to localhost:6379 in 234ms
info: StackExchange.Redis.Extensions.Core[3001] Redis client created: Default (database: 0)

Connection flap (reconnecting)

fail: StackExchange.Redis.Extensions.Core[2001] Redis connection failed: SocketFailure
warn: StackExchange.Redis.Extensions.Core[2002] Redis connection restored to localhost:6379

All connections down

warn: StackExchange.Redis.Extensions.Core[1003] All Redis connections are disconnected. Using connection 12345678 in degraded mode

This means SE.Redis is attempting reconnection. Operations will fail until at least one connection is restored. No action is needed — the pool automatically recovers.

Subscription handler failure

fail: StackExchange.Redis.Extensions.Core[4001] Error processing subscription message on channel orders:new
      System.InvalidOperationException: Failed to process order

The subscription is still active. The failed message was logged but the handler continues processing subsequent messages.

Pool initialization failure (e.g., Azure token expired)

fail: StackExchange.Redis.Extensions.Core[1006] Redis pool initialization failed at connection 2 of 5. Cleaning up 2 previously created connections

The 2 successfully created connections are properly disposed. The original exception will propagate to DI, failing the application startup.

Performance

All log messages use compile-time source generation ([LoggerMessage] attribute), which means:

  • Zero boxing of value-type parameters (int, long, double)
  • Zero string interpolation when the log level is disabled
  • No temporary allocations for message formatting
  • The IsEnabled() check is built into the generated code