public IMetricsCollector Build(ActorSystem system)
{
var log = Logging.GetLogger(system, GetType());
var settings = ClusterMetricsSettings.Create(system.Settings.Config);
var collectorCustom = settings.CollectorProvider;
var defaultCollector = typeof(DefaultCollector).AssemblyQualifiedName;
var useCustom = !settings.CollectorFallback;
var useInternal = settings.CollectorFallback && string.IsNullOrEmpty(settings.CollectorProvider);
Try <IMetricsCollector> Create(string provider)
{
log.Debug("Trying {0}", provider);
return(DynamicAccess.CreateInstanceFor <IMetricsCollector>(provider, system));
}
Try <IMetricsCollector> collector;
if (useCustom)
{
collector = Create(collectorCustom);
}
else if (useInternal)
{
collector = Create(defaultCollector);
}
else // Use complete fall back chain.
{
collector = Create(collectorCustom).OrElse(Create(defaultCollector));
}
return(collector.Recover(ex => throw new ConfigurationException($"Could not create metrics collector: {ex}")).Get());
}
private ServiceDiscovery CreateServiceDiscovery(string method)
{
var config = _system.Settings.Config;
string ClassNameFromConfig(string path) => config.HasPath(path)
? config.GetString(path)
: throw new ArgumentException($"{path} must contain field `class` that is a FQN of an `Akka.Discovery.ServiceDiscovery` implementation");
Try <ServiceDiscovery> Create(string typeName)
{
var dynamic = DynamicAccess.CreateInstanceFor <ServiceDiscovery>(typeName, _system);
return(dynamic.RecoverWith(ex => ex is TypeLoadException || ex is MissingMethodException
? DynamicAccess.CreateInstanceFor <ServiceDiscovery>(typeName)
: dynamic));
}
var configName = $"akka.discovery.{method}.class";
var instanceTry = Create(ClassNameFromConfig(configName));
return(instanceTry.IsSuccess switch
{
true => instanceTry.Get(),
false when instanceTry.Failure.Value is TypeLoadException || instanceTry.Failure.Value is MissingMethodException =>
throw new ArgumentException(nameof(method), $"Illegal {configName} value or incompatible class! \n" +
"The implementation class MUST extend Akka.Discovery.ServiceDiscovery and take an \n" +
"ExtendedActorSystem as constructor argument."),
_ => throw instanceTry.Failure.Value
});
/// <summary>
/// Builds <see cref="IMetricsSelector"/> defined in configuration
/// </summary>
/// <returns></returns>
public static IMetricsSelector BuildFromConfig(Config config)
{
if (config.IsNullOrEmpty())
{
throw ConfigurationException.NullOrEmptyConfig <IMetricsSelector>();
}
var selectorTypeName = config.GetString("metrics-selector");
switch (selectorTypeName)
{
case "mix": return(MixMetricsSelector.Instance);
case "memory": return(MemoryMetricsSelector.Instance);
case "cpu": return(CpuMetricsSelector.Instance);
default:
return(DynamicAccess.CreateInstanceFor <IMetricsSelector>(selectorTypeName, config)
.Recover(ex => throw new ArgumentException($"Cannot instantiate metrics-selector [{selectorTypeName}]," +
$"make sure it extends [Akka.Cluster.Metrics.MetricsSelector] and " +
$"has constructor with [Akka.Configuration.Config] parameter", ex))
.Get());
}
}
private ServiceDiscovery CreateServiceDiscovery(string method)
{
var config = _system.Settings.Config.GetConfig($"akka.discovery.{method}");
if (config is null)
{
throw new ArgumentException($"Could not load discovery config from path [akka.discovery.{method}]");
}
if (!config.HasPath("class"))
{
throw new ArgumentException($"akka.discovery.{method} must contain field `class` that is a FQN of an `Akka.Discovery.ServiceDiscovery` implementation");
}
Try <ServiceDiscovery> Create(string typeName)
{
var dynamic = DynamicAccess.CreateInstanceFor <ServiceDiscovery>(typeName, _system);
return(dynamic.RecoverWith(ex => ex is TypeLoadException || ex is MissingMethodException
? DynamicAccess.CreateInstanceFor <ServiceDiscovery>(typeName)
: dynamic));
}
var className = config.GetString("class");
_log.Info($"Starting Discovery service using [{method}] method, class: [{className}]");
var instanceTry = Create(className);
return(instanceTry.IsSuccess switch
{
true => instanceTry.Get(),
false when instanceTry.Failure.Value is TypeLoadException || instanceTry.Failure.Value is MissingMethodException =>
throw new ArgumentException(nameof(method), $"Illegal akka.discovery.{method}.class value or incompatible class! \n" +
"The implementation class MUST extend Akka.Discovery.ServiceDiscovery and take an \n" +
"ExtendedActorSystem as constructor argument."),
_ => throw instanceTry.Failure.Value
});
