private void UpdateSubchannelState(Subchannel subchannel, SubchannelState state)
{
var index = FindSubchannel(_addressSubchannels, subchannel);
if (index == null)
{
SubchannelsLoadBalancerLog.IgnoredSubchannelStateChange(_logger, subchannel.Id);
return;
}
SubchannelsLoadBalancerLog.ProcessingSubchannelStateChanged(_logger, subchannel.Id, state.State, state.Status);
UpdateBalancingState(state.Status);
if (state.State == ConnectivityState.TransientFailure || state.State == ConnectivityState.Idle)
{
SubchannelsLoadBalancerLog.RefreshingResolverForSubchannel(_logger, subchannel.Id, state.State);
Controller.RefreshResolver();
}
if (state.State == ConnectivityState.Idle)
{
SubchannelsLoadBalancerLog.RequestingConnectionForSubchannel(_logger, subchannel.Id, state.State);
subchannel.RequestConnection();
}
}
/// <inheritdoc />
public override void UpdateChannelState(ChannelState state)
{
if (state.Status.StatusCode != StatusCode.OK)
{
ResolverError(state.Status);
return;
}
if (state.Addresses == null || state.Addresses.Count == 0)
{
ResolverError(new Status(StatusCode.Unavailable, "Resolver returned no addresses."));
return;
}
var allUpdatedSubchannels = new List <AddressSubchannel>();
var newSubchannels = new List <Subchannel>();
var currentSubchannels = _addressSubchannels.ToList();
// The state's addresses is the new authoritative list of addresses.
// However, we want to keep existing subchannels when possible.
foreach (var address in state.Addresses)
{
// Check existing subchannels for a match.
var i = FindSubchannelByAddress(currentSubchannels, address);
AddressSubchannel newOrCurrentSubConnection;
if (i != null)
{
// There is a match so take current subchannel.
newOrCurrentSubConnection = currentSubchannels[i.GetValueOrDefault()];
// Remove from current collection because any subchannels
// remaining in this collection at the end will be disposed.
currentSubchannels.RemoveAt(i.GetValueOrDefault());
}
else
{
// No match so create a new subchannel.
var c = Controller.CreateSubchannel(new SubchannelOptions(new[] { address }));
c.OnStateChanged(s => UpdateSubchannelState(c, s));
newSubchannels.Add(c);
newOrCurrentSubConnection = new AddressSubchannel(c, address);
}
allUpdatedSubchannels.Add(newOrCurrentSubConnection);
}
// Any sub-connections still in this collection are no longer returned by the resolver.
// This can all be removed.
var removedSubConnections = currentSubchannels;
if (removedSubConnections.Count == 0 && newSubchannels.Count == 0)
{
SubchannelsLoadBalancerLog.ConnectionsUnchanged(_logger);
return;
}
foreach (var removedSubConnection in removedSubConnections)
{
RemoveSubchannel(removedSubConnection.Subchannel);
}
_addressSubchannels.Clear();
_addressSubchannels.AddRange(allUpdatedSubchannels);
// Start new connections after collection on balancer has been updated.
foreach (var c in newSubchannels)
{
c.RequestConnection();
}
UpdateBalancingState(state.Status);
}