public LocalShardCheckHeartbeatTask(IShard shard, NodeContext context, MembershipManager membershipManager, ClusterConfigurationManager clusterConfigMgr)
{
this._shard = shard;
this._context = context;
this._clusterConfigMgr = clusterConfigMgr;
_localShardHeartbeatReporter = new LocalShardHeartbeatReporting(_context.LocalAddress);
this._membershipManager = membershipManager;
this._membershipManager.HeartbeatReport = _localShardHeartbeatReporter;
ShardConfiguration sConfig = null;
if (_clusterConfigMgr != null)
{
sConfig = _clusterConfigMgr.GetShardConfiguration(context.LocalShardName);
}
if (sConfig != null && sConfig.NodeHeartbeatInterval > 0)
{
this._poolingThreshold = (sConfig.NodeHeartbeatInterval * 2) * 1000;
}
_running = false;
_startSignal = new ManualResetEvent(false);
//with the initialization of the heartbeat receiver, we start the send heart beat task.
_sendHearbeatTask = new LocalShardSendHeartbeatTask(context, shard, _membershipManager, clusterConfigMgr);
}
//RTD: revisit this logic
public object Clone()
{
LocalShardHeartbeatReporting clone = new LocalShardHeartbeatReporting(_minReplicatedOperation.Key);
clone._heartbeatReporter = new Dictionary <Address, HeartbeatInfo>();
IList <Address> nodes = this._heartbeatReporter.Keys.ToList();
foreach (var node in nodes)
{
HeartbeatInfo info = _heartbeatReporter[node];
lock (info)
{
clone._heartbeatReporter.Add(node, (HeartbeatInfo)info.Clone());
}
}
return(clone);
}
/// <summary>
/// function needs to be shifted from here.
/// this function provides a mini election feasibility check to avoid continuous triggering of the
/// election mechanism.
/// Steps:
/// 1. Does the node possess a majority of the connections.
/// 2. If yes, proceed to the next step where the primary is hunted for in the existing heartbeat report table.
/// </summary>
/// <param name="report"></param>
/// <returns></returns>
private bool AreElectionsFeasible(LocalShardHeartbeatReporting report, ShardConfiguration sConfig)
{
IList <Address> activeServers = report.GetReportTable.Keys.ToList();
if (activeServers.Count < (int)Math.Ceiling((double)sConfig.Servers.Nodes.Count / 2))
{
return(false);
}
else
{
if (report.PrimaryExists())
{
// We verify if a primary exists on any of the nodes at any given point in time and if a channel exists
// because there is a possibility that the primary is not stepping down and is not a valid primary either
// (catering for split - brain scenarios)
return(!ChannelExists(report.GetCurrentPrimary()));
}
}
return(true);
}
