PhiAccrualFailureDetector now needs a new param

[aley1]

Hi Sakno,

Before upgrading to version 4.5, I was using the PhiAccrualFailureDetector as the failure detection mechanism
var cluster = new RaftCluster(configuration)
{
FailureDetectorFactory = static member => new PhiAccrualFailureDetector() { Threshold = 3D },
};

Now it doesn't work - it looks a new param (estimatedFirstHeartbeat) is needed.
Could you please kindly explain what are the implications / use of this param?
And I tried initiating it with a new TimeSpan but doesn't work.

[sakno]

estimatedFirstHeartbeat is required to initialize internal reservoir of samples. It is presented in all other implementations. Having this class without estimatedFirstHeartbeat is a result of bad design from my side. This is why it was modified. estimatedFirstHeartbeat represents a guess about response time of the first heartbeat message produced by the leader. You can set it to lower election timeout optimistically.