Performance: "Eventorderer" messages in logs

Answer: The "Eventorderer" is part of a system in TOPdesk which ensures that user actions in TOPdesk are performed in the right order. Every action or key press of a user is immediately sent to TOPdesk. It is important that these actions are performed in the right order. These actions travel to TOPdesk via a network. These networks, however, do not give any guarantees about delivery other than a ‘best-effort’ attempt at delivery. Not regarding speed, order, or the question of whether the actions are delivered at all. To help manage this situation, TOPdesk has the Eventorderer (among other processes). Every action in TOPdesk is sent to TOPdesk accompanied by a sequence number. TOPdesk will check, based on the sequence number, whether actions are received in the right order. If not, it will detect this based on this sequence number. If a user sends actions ‘12345’ but TOPdesk receives ‘124’, TOPdesk will notice (and log) this and wait for a short while to see if action ‘3’ is still received. If so, TOPdesk will place action ‘3’ in the right location based on the sequence number and continue normal operations. It may occur that the action is never received, or at least not in the desired time frame. As TOPdesk does not know what the contents of action ‘3’ are, TOPdesk cannot correct the sequence at the side of TOPdesk. To ensure the situation at the side of TOPdesk and the browser is in sync, TOPdesk will correct the browser-side. At this moment a user might notice reduced performance of TOPdesk and more noticeably the fact that texts ‘disappear’ or ‘jump back’. In the log files of TOPdesk these events can be seen as notifications of the Eventorderer that are ‘dropped’ or ‘timeout’. These notifications of the Eventorderer usually occur when there is something (negatively) influencing the connection between browser and TOPdesk server. This could be the network itself, although often this is caused by an intermediate service such as a firewall, proxy or gateway which might be too busy to handle all the traffic from TOPdesk. Note: certain virus scanners have a built-in proxy to scan certain types of network traffic and can also cause this problem. If an intermediate service is too busy to handle the traffic, quite likely the service will ‘drop’ the network traffic. Because TOPdesk keeps (and expects) a continuous connection between browser and TOPdesk, and because of the fact that every action is sent to TOPdesk individually, TOPdesk is very sensitive to disruptions such as dropped packets. The advice would be to, if possible, exclude TOPdesk from intermediate proxies, virus scanners or other services. It may also help to add the TOPdesk URL to your ‘local intranet’-zone or try to reach TOPdesk via another browser. Firefox is often less affected by intermediate services because Firefox has its own settings for proxies and is often not affected by a virus scanner.