Tutti avranno più o meno sperimentato il blackout di
Skype che dal 16 AGOSTO si è protratto anche per 2 giorni (per alcuni utenti).
Skype, una rivoluzione nel mondo delle comunicazioni VOIP, tuttavia non un protocollo Open, nè una connessione P2P diretta ma sempre passante per un server centrale che quindi soffre di tutti i problemi che il modello client server presenta.
Anche se la colpa sembra sia dovuta ad un aggiornamento di Windows che ha comportato il riavvio di milioni di utenti e conseguente ri-login simultaneo.
On Thursday, 16th August 2007, the Skype peer-to-peer network became unstable and suffered a critical disruption. The disruption was triggered by a massive restart of our users’ computers across the globe within a very short timeframe as they re-booted after receiving a routine set of patches through Windows Update.
The high number of restarts affected Skype’s network resources. This caused a flood of log-in requests, which, combined with the lack of peer-to-peer network resources, prompted a chain reaction that had a critical impact.
Normally Skype’s peer-to-peer network has an inbuilt ability to self-heal, however, this event revealed a previously unseen software bug within the network resource allocation algorithm which prevented the self-healing function from working quickly. Regrettably, as a result of this disruption, Skype was unavailable to the majority of its users for approximately two days.
The issue has now been identified explicitly within Skype. We can confirm categorically that no malicious activities were attributed or that our users’ security was not, at any point, at risk.
Internet nasce come rete a prova di attacco nucleare, in grado di sopperire,teoricamente, ad interruzioni di linea e distruzioni grazie alla nidificazione dei collegamenti, ora mi domando come mai un programma rivoluzionario come Skype, vero motore di sviluppo delle comunicazioni "Over IP" non abbia mutuato da Internet questa capacità di sopperire, perchè tutto è caduto e perchè proprio dopo un riavvio, uno come mille nel mondo Microsoft?
1. Are we blaming Microsoft for what happened?
We don’t blame anyone but ourselves. The Microsoft Update patches were merely a catalyst — a trigger — for a series of events that led to the disruption of Skype, not the root cause of it. And Microsoft has been very helpful and supportive throughout.
The high number of post-update reboots affected Skype’s network resources. This caused a flood of log-in requests, which, combined with the lack of peer-to-peer network resources at the time, prompted a chain reaction that had a critical impact. The self-healing mechanisms of the P2P network upon which Skype’s software runs have worked well in the past. Simply put, every single time Skype has needed to recover from reboots that naturally accompany a routine Windows Update, there hasn’t been a problem.
Unfortunately, this time, for the first time, Skype was unable to rise to the challenge and the reasons for this were exceptional. In this instance, the day’s Skype traffic patterns, combined with the large number of reboots, revealed a previously unseen fault in the P2P network resource allocation algorithm Skype used. Consequently, the P2P network’s self-healing function didn’t work quickly enough. Skype’s peer-to-peer core was not properly tuned to cope with the load and core size changes that occurred on August 16. The reboots resulting from software patching merely served as a catalyst. This combination of factors created a situation where the self-healing needed outside intervention and assistance by our engineers.
Da imprenditore ossessionato da bug e imperfezioni software e hardware mi consolo e mi pongo anche un interrogativo, è possibile creare l'applicazione perfetta? Voglio dire ingegneri e programmatori di Skype non sono gli ultimi arrivati eppure non sono riusciti ad analizzare-prevedere questo problema.
L'affidabilità di Internet ne risentirà, bisogna ancora lavorare duro per rendere affidabile il software e l'hardware che lo compongono? Siamo forse in ritardo rispetto al traffico?
