/// <summary>
/// This method allows CASaaS to replace the host's logger for our own logger.
/// </summary>
/// <remarks>
/// Since we don't perform any kind of stats aggregation on our side (i.e. statsd, MDM, etc), we rely on
/// the host to do it. This is done through <see cref="MetricsAdapter"/>.
///
/// The situation with respect to shutdown is a little bit odd: we create a custom target, which holds some
/// managed resources that need to be released (because this release ensures any remaining logs will be
/// sent to Kusto).
/// NLog will make sure to dispose those resources when we shut it down, but we may actually return the
/// host's logger, in which case we don't consider that we own it, because clean up may happen on whatever
/// code is actually using us, so we don't want to dispose in that case.
/// </remarks>
public static (ILogger Logger, IDisposable DisposableToken) CreateReplacementLogger(LoggerFactoryArguments arguments)
{
var logger = arguments.Logger;
var loggingSettings = arguments.LoggingSettings;
if (string.IsNullOrEmpty(loggingSettings?.NLogConfigurationPath))
{
return(logger, null);
}
// This context is associated to the host's logger. In this way, we can make sure that if we have any
// issues with our logging, we can always go and read the host's logs to figure out what's going on.
var context = new Context(logger);
var operationContext = new OperationContext(context);
Tracer.Info(context, $"Replacing cache logger for NLog-based implementation using configuration file at `{loggingSettings.NLogConfigurationPath}`");
try
{
var nLogAdapter = CreateNLogAdapter(operationContext, arguments);
context = new Context(nLogAdapter);
if (arguments.Logger is IOperationLogger operationLogger)
{
// NOTE(jubayard): the MetricsAdapter doesn't own the loggers, and hence won't dispose them. This
// means we don't change the disposableToken.
Tracer.Debug(context, "Creating MetricsAdapter with an existing 'operationLogger'.");
var wrapper = new MetricsAdapter(nLogAdapter, operationLogger);
return(wrapper, nLogAdapter);
}
// The current implementation now supports the mdm metrics as well.
if (!string.IsNullOrEmpty(arguments.LoggingSettings.MdmAccountName))
{
Tracer.Debug(context, "Creating MetricsLogger with an in-proc MdmOperationLogger.");
operationLogger = MdmOperationLogger.Create(context, arguments.LoggingSettings.MdmAccountName, GetDefaultDimensions(arguments));
var wrapper = new MetricsAdapter(nLogAdapter, operationLogger);
return(wrapper, nLogAdapter);
}
return(nLogAdapter, nLogAdapter);
}
catch (Exception e)
{
Tracer.Error(context, $"Failed to instantiate NLog-based logger with error: {e}");
return(logger, null);
}
}
/// <summary>
/// This method allows CASaaS to replace the host's logger for our own logger.
/// </summary>
/// <remarks>
/// Since we don't perform any kind of stats aggregation on our side (i.e. statsd, MDM, etc), we rely on
/// the host to do it. This is done through <see cref="MetricsAdapter"/>.
///
/// The situation with respect to shutdown is a little bit odd: we create a custom target, which holds some
/// managed resources that need to be released (because this release ensures any remaining logs will be
/// sent to Kusto).
/// NLog will make sure to dispose those resources when we shut it down, but we may actually return the
/// host's logger, in which case we don't consider that we own it, because clean up may happen on whatever
/// code is actually using us, so we don't want to dispose in that case.
/// </remarks>
public static (ILogger Logger, IDisposable DisposableToken) CreateReplacementLogger(LoggerFactoryArguments arguments)
{
Contract.RequiresNotNull(arguments.TelemetryFieldsProvider);
var logger = arguments.Logger;
var loggingSettings = arguments.LoggingSettings;
if (string.IsNullOrEmpty(loggingSettings?.NLogConfigurationPath))
{
return(logger, null);
}
// This context is associated to the host's logger. In this way, we can make sure that if we have any
// issues with our logging, we can always go and read the host's logs to figure out what's going on.
var context = new Context(logger);
var operationContext = new OperationContext(context);
context.Info($"Replacing cache logger for NLog-based implementation using configuration file at `{loggingSettings.NLogConfigurationPath}`");
try
{
var nLogAdapter = CreateNLogAdapter(operationContext, arguments);
if (arguments.Logger is IOperationLogger operationLogger)
{
// NOTE(jubayard): the MetricsAdapter doesn't own the loggers, and hence won't dispose them. This
// means we don't change the disposableToken.
var wrapper = new MetricsAdapter(nLogAdapter, operationLogger);
return(wrapper, nLogAdapter);
}
return(nLogAdapter, nLogAdapter);
}
catch (Exception e)
{
context.Error($"Failed to instantiate NLog-based logger with error: {e}");
return(logger, null);
}
}
