For instance, to establish a retry policy for a RavenDB data provider,
ensuring that insert/replace operations are retried no more than twice in the event of a RavenException:
var ravenDbProvider = new RavenDbDataProvider(r => r
.WithSettings(s => s
.Urls("http://127.0.0.1:8080")
.Database(_ => "Audit")));
Audit.Core.Configuration.Setup()
.UsePolly(p => p
.DataProvider(ravenDbProvider)
.WithResilience(resilience => resilience
.AddRetry(new()
{
ShouldHandle = new PredicateBuilder().Handle<RavenException>(),
Delay = TimeSpan.FromSeconds(1),
MaxRetryAttempts = 2
})));
Extension for Fallback
To facilitate the fallback to a different Data Provider you can use the FallbackToDataProvider() extension method in the FallbackAction.
For instance, to establish a fallback policy for a RavenDB data provider,
ensuring that in the event of a RavenException, the Audit Events will be written to a file using a File data provider as a fallback:
using Audit.Polly;
var ravenDbProvider = new RavenDbDataProvider(...);
var fallbakDbProvider = new FileDataProvider(...);
Audit.Core.Configuration.Setup()
.UsePolly(p => p
.DataProvider(ravenDbProvider)
.WithResilience(resilience => resilience
.AddFallback(new()
{
ShouldHandle = new PredicateBuilder().Handle<RavenException>(),
FallbackAction = args => args.FallbackToDataProvider(fallbakDbProvider)
})));
Extension for hedging
To facilitate the hedging strategy you can use the FallbackToDataProvider() extension method in the ActionGenerator.
For instance, to establish a hedging policy for a data provider so in case of exceptions, the Audit Events will be written to a different data provider using a hedging strategy:
using Audit.Polly;
var primaryDataProvider = new SqlDataProvider(...);
var secondaryDataProvider = new FileDataProvider(...);
Audit.Core.Configuration.Setup()
.UsePolly(p => p
.DataProvider(primaryDataProvider)
.WithResilience(r => r
.AddHedging(new()
{
ShouldHandle = new PredicateBuilder().Handle<SqlException>(),
MaxHedgedAttempts = 2,
Delay = TimeSpan.Zero,
ActionGenerator = args => args.FallbackToDataProvider(secondaryDataProvider)
}));
Settings
DataProvider: The primary data provider to use.
WithResilience: The resilience strategy to apply to the primary data provider. It can be a single policy or a collection of policies.
Resilience Strategies
The following are some of the available resilience policies to apply to the primary data provider.
AddRetry: Adds a retry policy to the primary data provider.
AddFallback: Adds a fallback policy to the primary data provider.
AddCircuitBreaker: Adds a circuit breaker policy to the primary data provider.
AddTimeout: Adds a timeout policy to the primary data provider.
AddHedging: Adds a hedging policy to the primary data provider.
