/// <summary>
/// Checks if any of the neighbors expired.
/// If so, it starts the process of their removal.
/// </summary>
public async Task CheckExpiredNeighborsAsync()
{
log.Trace("()");
// If a neighbor server's LastRefreshTime is lower than this limit, it is expired.
DateTime limitLastRefreshTime = DateTime.UtcNow.AddSeconds(-Config.Configuration.NeighborProfilesExpirationTimeSeconds);
using (UnitOfWork unitOfWork = new UnitOfWork())
{
bool success = false;
DatabaseLock[] lockObjects = new DatabaseLock[] { UnitOfWork.NeighborLock, UnitOfWork.NeighborhoodActionLock };
using (IDbContextTransaction transaction = await unitOfWork.BeginTransactionWithLockAsync(lockObjects))
{
try
{
List <Neighbor> expiredNeighbors = (await unitOfWork.NeighborRepository.GetAsync(n => n.LastRefreshTime < limitLastRefreshTime, null, true)).ToList();
if (expiredNeighbors.Count > 0)
{
log.Debug("There are {0} expired neighbors.", expiredNeighbors.Count);
foreach (Neighbor neighbor in expiredNeighbors)
{
// This action will cause our profile server to erase all profiles of the neighbor that has been removed.
NeighborhoodAction action = new NeighborhoodAction()
{
ServerId = neighbor.NeighborId,
Timestamp = DateTime.UtcNow,
Type = NeighborhoodActionType.RemoveNeighbor,
TargetIdentityId = null,
AdditionalData = null
};
await unitOfWork.NeighborhoodActionRepository.InsertAsync(action);
}
await unitOfWork.SaveThrowAsync();
transaction.Commit();
}
else
{
log.Debug("No expired neighbors found.");
}
success = true;
}
catch (Exception e)
{
log.Error("Exception occurred: {0}", e.ToString());
}
if (!success)
{
log.Warn("Rolling back transaction.");
unitOfWork.SafeTransactionRollback(transaction);
}
unitOfWork.ReleaseLock(lockObjects);
}
}
log.Trace("(-)");
}
