public async Task HandlesDistributedCacheFailuresInTheMiddleOfAnOperationAsync()
{
using (var memoryCache = new MemoryCache(new MemoryCacheOptions()))
{
var distributedCache = new MemoryDistributedCache(Options.Create(new MemoryDistributedCacheOptions()));
var chaosDistributedCache = new ChaosDistributedCache(distributedCache);
using (var fusionCache = new FusionCache(new FusionCacheOptions(), memoryCache).SetupDistributedCache(chaosDistributedCache, new FusionCacheNewtonsoftJsonSerializer()))
{
var task = fusionCache.GetOrSetAsync <int>("foo", async _ => { await Task.Delay(2_000); return(42); }, new FusionCacheEntryOptions(TimeSpan.FromSeconds(10)));
await Task.Delay(500);
chaosDistributedCache.SetAlwaysThrow();
var value = await task;
chaosDistributedCache.SetNeverThrow();
// END RESULT IS WHAT EXPECTED
Assert.Equal(42, value);
// MEMORY CACHE HAS BEEN UPDATED
Assert.Equal(42, memoryCache.Get <FusionCacheEntry <int> >("foo").Value);
// DISTRIBUTED CACHE HAS -NOT- BEEN UPDATED
Assert.Null(distributedCache.GetString("foo"));
}
}
}
public void DistributedCacheCircuitBreakerActuallyWorks()
{
var circuitBreakerDuration = TimeSpan.FromSeconds(2);
var distributedCache = new MemoryDistributedCache(Options.Create(new MemoryDistributedCacheOptions()));
var chaosDistributedCache = new ChaosDistributedCache(distributedCache);
using (var memoryCache = new MemoryCache(new MemoryCacheOptions()))
{
using (var fusionCache = new FusionCache(new FusionCacheOptions()
{
DistributedCacheCircuitBreakerDuration = circuitBreakerDuration
}, memoryCache))
{
fusionCache.DefaultEntryOptions.AllowBackgroundDistributedCacheOperations = false;
fusionCache.SetupDistributedCache(chaosDistributedCache, new FusionCacheNewtonsoftJsonSerializer());
fusionCache.Set <int>("foo", 1, options => options.SetDurationSec(60).SetFailSafe(true));
chaosDistributedCache.SetAlwaysThrow();
fusionCache.Set <int>("foo", 2, options => options.SetDurationSec(60).SetFailSafe(true));
chaosDistributedCache.SetNeverThrow();
fusionCache.Set <int>("foo", 3, options => options.SetDurationSec(60).SetFailSafe(true));
Thread.Sleep(circuitBreakerDuration);
memoryCache.Remove("foo");
var res = fusionCache.GetOrDefault <int>("foo", -1);
Assert.Equal(1, res);
}
}
}
public async Task DistributedCacheCircuitBreakerActuallyWorksAsync(SerializerType serializerType)
{
var circuitBreakerDuration = TimeSpan.FromSeconds(2);
var distributedCache = new MemoryDistributedCache(Options.Create(new MemoryDistributedCacheOptions()));
var chaosDistributedCache = new ChaosDistributedCache(distributedCache);
using (var memoryCache = new MemoryCache(new MemoryCacheOptions()))
{
using (var fusionCache = new FusionCache(new FusionCacheOptions()
{
DistributedCacheCircuitBreakerDuration = circuitBreakerDuration
}, memoryCache))
{
fusionCache.DefaultEntryOptions.AllowBackgroundDistributedCacheOperations = false;
fusionCache.SetupDistributedCache(chaosDistributedCache, GetSerializer(serializerType));
await fusionCache.SetAsync <int>("foo", 1, options => options.SetDurationSec(60).SetFailSafe(true));
chaosDistributedCache.SetAlwaysThrow();
await fusionCache.SetAsync <int>("foo", 2, options => options.SetDurationSec(60).SetFailSafe(true));
chaosDistributedCache.SetNeverThrow();
await fusionCache.SetAsync <int>("foo", 3, options => options.SetDurationSec(60).SetFailSafe(true));
await Task.Delay(circuitBreakerDuration).ConfigureAwait(false);
memoryCache.Remove("foo");
var res = await fusionCache.GetOrDefaultAsync <int>("foo", -1);
Assert.Equal(1, res);
}
}
}
public async Task HandlesDistributedCacheFailuresAsync()
{
var distributedCache = new MemoryDistributedCache(Options.Create(new MemoryDistributedCacheOptions()));
var chaosDistributedCache = new ChaosDistributedCache(distributedCache);
using (var fusionCache = new FusionCache(new FusionCacheOptions()).SetupDistributedCache(chaosDistributedCache, new FusionCacheNewtonsoftJsonSerializer()))
{
var initialValue = await fusionCache.GetOrSetAsync <int>("foo", _ => Task.FromResult(42), new FusionCacheEntryOptions()
{
Duration = TimeSpan.FromSeconds(1), IsFailSafeEnabled = true
});
await Task.Delay(1_500);
chaosDistributedCache.SetAlwaysThrow();
var newValue = await fusionCache.GetOrSetAsync <int>("foo", async _ => throw new Exception("Generic error"), new FusionCacheEntryOptions(TimeSpan.FromSeconds(1)) { IsFailSafeEnabled = true });;
Assert.Equal(initialValue, newValue);
}
}