/// <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.NeighborExpirationTimeSeconds);
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 proximity server to erase all activities of the neighbor that has been removed.
NeighborhoodAction action = new NeighborhoodAction()
{
ServerId = neighbor.NeighborId,
Timestamp = DateTime.UtcNow,
Type = NeighborhoodActionType.RemoveNeighbor,
TargetActivityId = null,
TargetActivityOwnerId = 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("(-)");
}
/// <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.NeighborExpirationTimeSeconds);
List <byte[]> neighborsToDeleteIds = new List <byte[]>();
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)
{
bool saveDb = false;
log.Debug("There are {0} expired neighbors.", expiredNeighbors.Count);
foreach (Neighbor neighbor in expiredNeighbors)
{
int unprocessedRemoveNeighborActions = await unitOfWork.NeighborhoodActionRepository.CountAsync(a => (a.ServerId == neighbor.NetworkId) && (a.Type == NeighborhoodActionType.RemoveNeighbor));
if (unprocessedRemoveNeighborActions == 0)
{
// This action will cause our proximity server to erase all profiles of the neighbor that has been removed.
NeighborhoodAction action = new NeighborhoodAction()
{
ServerId = neighbor.NetworkId,
Timestamp = DateTime.UtcNow,
Type = NeighborhoodActionType.RemoveNeighbor,
TargetActivityId = 0,
TargetActivityOwnerId = null,
AdditionalData = null
};
await unitOfWork.NeighborhoodActionRepository.InsertAsync(action);
saveDb = true;
}
else
{
log.Debug("There is an unprocessed RemoveNeighbor neighborhood action for neighbor ID '{0}'. Neighbor will be deleted.", neighbor.NetworkId.ToHex());
neighborsToDeleteIds.Add(neighbor.NetworkId);
}
}
if (saveDb)
{
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);
}
if (neighborsToDeleteIds.Count > 0)
{
log.Debug("There are {0} neighbors to be deleted.", neighborsToDeleteIds.Count);
foreach (byte[] neighborToDeleteId in neighborsToDeleteIds)
{
if (await unitOfWork.NeighborRepository.DeleteNeighborAsync(neighborToDeleteId))
{
log.Debug("Neighbor ID '{0}' deleted.", neighborToDeleteId.ToHex());
}
else
{
log.Warn("Unable to delete neighbor ID '{0}'.", neighborToDeleteId.ToHex());
}
}
}
else
{
log.Debug("No neighbors to delete now.");
}
}
log.Trace("(-)");
}
