public async Task <bool> AttemptToScaleAsync(RuleContext context, RedisInstance redisInstance, CancellationToken cancellationToken)
{
Contract.Requires(redisInstance == _primaryRedisInstance || redisInstance == _secondaryRedisInstance);
Contract.Requires(redisInstance.IsReadyToScale);
// Fetch which cluster size we want, and start scaling operation if needed.
var currentClusterSize = redisInstance.ClusterSize;
var targetClusterSizeResult = await _redisAutoscalingAgent.EstimateBestClusterSizeAsync(redisInstance, cancellationToken);
if (!targetClusterSizeResult.Succeeded)
{
Emit(context, "Autoscale", Severity.Error, $"Failed to find best plan for instance `{redisInstance.Name}` in plan `{currentClusterSize}`. Result=[{targetClusterSizeResult}]");
return(false);
}
var modelOutput = targetClusterSizeResult.Value;
Contract.AssertNotNull(modelOutput);
var targetClusterSize = modelOutput.TargetClusterSize;
if (targetClusterSize.Equals(redisInstance.ClusterSize) || modelOutput.ScalePath.Count == 0)
{
// No autoscale required
return(false);
}
Emit(context, "Autoscale", Severity.Warning, $"Autoscaling from `{currentClusterSize}` to `{targetClusterSize}` via scale path `{currentClusterSize} -> {string.Join(" -> ", modelOutput.ScalePath)}` for instance `{redisInstance.Name}`. Solution cost is `{modelOutput.Cost}`");
await redisInstance.ScaleAsync(modelOutput.ScalePath, cancellationToken).ThrowIfFailureAsync();
return(true);
}
public async Task <Result <ModelOutput> > EstimateBestClusterSizeAsync(RedisInstance redisInstance, CancellationToken cancellationToken = default)
{
var now = DateTime.UtcNow;
var redisAzureId = redisInstance.RedisCache.Id;
var currentClusterSize = redisInstance.ClusterSize;
var modelContext = await ComputeFeaturesAsync(now, redisAzureId, currentClusterSize, cancellationToken);
return(Predict(currentClusterSize, modelContext));
}
public RedisAutoscalingRule(Configuration configuration, RedisAutoscalingAgent redisAutoscalingAgent, RedisInstance primaryRedisInstance, RedisInstance secondaryRedisInstance)
: base(configuration)
{
Contract.Assert(primaryRedisInstance != secondaryRedisInstance);
_configuration = configuration;
_redisAutoscalingAgent = redisAutoscalingAgent;
_primaryRedisInstance = primaryRedisInstance;
_secondaryRedisInstance = secondaryRedisInstance;
}
