Notre API WebSocket v1 est destinée à fournir une source persistante de nos données de marché (tickers, carnets d'ordres, temps et ventes, etc.), mais parfois les connexions WebSocket sont interrompues de manière inattendue par Cloudflare.
Les déconnexions initiées par Cloudflare entraînent généralement des erreurs réseau, telles que l'erreur 1006 suivante :
Erreur de lecture depuis le websocket : fermeture 1006 (fermeture anormale) : EOF inattendu
ou l'erreur suivante où Python lève une exception en essayant de lire un nouveau message de données de marché à partir d'une connexion déjà fermée :
websocket._exceptions.WebSocketConnectionClosedException: la socket est déjà fermée
Bien qu'il n'existe aucune solution pour empêcher ce type de déconnexions inattendues, il existe des contournements très efficaces. Si vous rencontrez des déconnexions WebSocket fréquentes, nous vous recommandons de mettre en œuvre une ou plusieurs des solutions suivantes :
Les précautions de sécurité de Cloudflare sont souvent appliquées à des adresses IP spécifiques, à des groupes d'adresses IP similaires (comme un bloc de classe C) ou à certaines zones géographiques. Par conséquent, changer votre adresse IP est parfois une solution simple mais efficace.
Par exemple, héberger votre logiciel API dans une région AWS différente ou utiliser un VPN dans une zone géographique différente modifierait considérablement l'adresse IP locale et pourrait potentiellement résoudre le problème de déconnexion inattendue.
L'utilisation d'une seule connexion WebSocket surveillée pour toute déconnexion involontaire, puis reconnectée et réabonnée si nécessaire, est une autre solution simple mais efficace. Voici un exemple de code Python de base montrant comment reconnecter et réabonner une connexion WebSocket chaque fois qu'une exception WebSocketConnectionClosed est levée :
#!/usr/bin/env python3 import sys from websocket import create_connection ws = create_connection('wss://ws.kraken.com/') print(ws.recv()) ws.send('{"event":"subscribe", "subscription":{"name":"ticker"}, "pair":["XBT/USD"]}') print(ws.recv()) for count in range(100): if count == 30 or count == 60: ws.close() try: print(ws.recv()) except: ws = create_connection('wss://ws.kraken.com/') print(ws.recv()) ws.send('{"event":"subscribe", "subscription":{"name":"ticker"}, "pair":["XBT/USD"]}') print(ws.recv()) ws.close() sys.exit(0)
Comme le montre l'exemple de sortie suivant, la connexion et l'abonnement WebSocket sont renouvelés chaque fois que la connexion est interrompue de manière inattendue (à 30 et 60 itérations de la boucle) :
{"connectionID":8986307948074364287,"event":"systemStatus","status":"online","version":"1.0.1"} {"channelID":274,"channelName":"ticker","event":"subscriptionStatus","pair":"XBT/USD","status":"subscribed","subscription":{"name":"ticker"}} [274,{"a":["9766.00000",16,"16.15314657"],"b":["9765.90000",16,"16.06793017"],"c":["9766.00000","0.15407543"],"v":["934.89117067","6431.35804307"],"p":["9793.82728","9736.03263"],"t":[3442,18738],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.80000"]},"ticker","XBT/USD"] {"event":"heartbeat"} ... [274,{"a":["9766.00000",15,"15.80052495"],"b":["9765.90000",15,"15.09399036"],"c":["9766.00000","0.18958527"],"v":["935.24379229","6430.73154248"],"p":["9793.81679","9736.04572"],"t":[3444,18738],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] [274,{"a":["9766.00000",15,"15.59644495"],"b":["9765.90000",15,"15.09399036"],"c":["9766.00000","0.20408000"],"v":["935.44787229","6430.93562248"],"p":["9793.81072","9736.04667"],"t":[3445,18739],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] {"event":"heartbeat"} [274,{"a":["9766.00000",11,"11.59644495"],"b":["9765.90000",20,"20.24943617"],"c":["9766.00000","4.00000000"],"v":["939.44787229","6434.93562248"],"p":["9793.69231","9736.06529"],"t":[3446,18740],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] {"connectionID":14767302623274336124,"event":"systemStatus","status":"online","version":"1.0.1"} {"channelID":274,"channelName":"ticker","event":"subscriptionStatus","pair":"XBT/USD","status":"subscribed","subscription":{"name":"ticker"}} [274,{"a":["9766.00000",11,"11.59644495"],"b":["9765.90000",20,"20.24943617"],"c":["9766.00000","4.00000000"],"v":["939.44787229","6434.93562248"],"p":["9793.69231","9736.06529"],"t":[3446,18740],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] [274,{"a":["9766.00000",8,"8.49644495"],"b":["9765.90000",21,"21.50083276"],"c":["9766.00000","1.50355505"],"v":["942.54787229","6438.03562248"],"p":["9793.60123","9736.07971"],"t":[3448,18742],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] {"event":"heartbeat"} {"event":"heartbeat"} [274,{"a":["9766.00000",4,"4.19644495"],"b":["9765.90000",22,"22.67116661"],"c":["9766.00000","4.30000000"],"v":["946.84787229","6442.33562248"],"p":["9793.47588","9736.09968"],"t":[3449,18743],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] ... {"event":"heartbeat"} {"connectionID":11355575731659611126,"event":"systemStatus","status":"online","version":"1.0.1"} {"channelID":274,"channelName":"ticker","event":"subscriptionStatus","pair":"XBT/USD","status":"subscribed","subscription":{"name":"ticker"}} [274,{"a":["9766.00000",4,"4.00000071"],"b":["9765.90000",21,"21.97845481"],"c":["9766.00000","0.19644424"],"v":["947.04431653","6442.53206672"],"p":["9793.47018","9736.10059"],"t":[3450,18744],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] [274,{"a":["9766.00000",3,"3.85443405"],"b":["9765.90000",19,"19.69673762"],"c":["9766.00000","0.14556666"],"v":["947.18988319","6442.67763338"],"p":["9793.46596","9736.10127"],"t":[3451,18745],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] {"event":"heartbeat"} {"event":"heartbeat"} [274,{"a":["9766.00000",3,"3.51109438"],"b":["9765.90000",19,"19.69673762"],"c":["9766.00000","0.16647855"],"v":["947.53322286","6443.02097305"],"p":["9793.45601","9736.10286"],"t":[3453,18747],"l":["9731.30000","9465.00000"],"h":["9845.00000","9884.70000"],"o":["9792.10000","9660.70000"]},"ticker","XBT/USD"] ...
L'utilisation de plusieurs (deux ou plus) connexions WebSocket redondantes est généralement la solution la plus efficace aux déconnexions WebSocket inattendues, car elle permet aux flux de données de marché de continuer sans interruption, quelle que soit la fréquence à laquelle les connexions sous-jacentes sont terminées.
L'exemple de code Python de base suivant montre comment implémenter plusieurs connexions WebSocket avec basculement automatique :
#!/usr/bin/env python3 import sys from websocket import create_connection ws = [ None, None ] data = [ "", "" ] ws[0] = create_connection("wss://ws.kraken.com/") print("WebSocket (Primary): %s" % ws[0].recv()) ws[1] = create_connection("wss://ws.kraken.com/") print("WebSocket (Backup): %s" % ws[1].recv()) ws[0].send('{"event":"subscribe", "subscription":{"name":"spread"}, "pair":["XBT/USD"]}') print("WebSocket (Primary): %s" % ws[0].recv()) ws[1].send('{"event":"subscribe", "subscription":{"name":"spread"}, "pair":["XBT/USD"]}') print("WebSocket (Backup): %s" % ws[1].recv()) source = 0 for count in range(100): try: try: data[0] = ws[0].recv() except Exception: source = 1 try: data[1] = ws[1].recv() except Exception: source = 0 except KeyboardInterrupt: ws[0].close() print("WebSocket (%(source)s): %(data)s" % {"source":"Primary" if source == 0 else "Backup", "data":data[source]}) ws[source].close() sys.exit(1)
Le code ci-dessus crée deux connexions WebSocket et abonne les deux connexions au même flux de données de marché. La connexion principale est utilisée pour afficher les données de marché, jusqu'à ce qu'une interruption clavier soit générée (via Ctrl+C, par exemple), ce qui ferme la connexion principale. Les lectures ultérieures de la connexion principale lèvent une exception, qui est interceptée et utilisée pour changer la source des données de marché vers la connexion de secours, qui est ensuite utilisée pour afficher les données de marché.
L'exemple de sortie suivant montre comment la source des données de marché passe de la connexion principale à la connexion de secours sans interrompre le flux de données de marché :
WebSocket (Primary): {"connectionID":6894434610526943167,"event":"systemStatus","status":"online","version":"1.0.1"} WebSocket (Backup): {"connectionID":11520162761468018366,"event":"systemStatus","status":"online","version":"1.0.1"} WebSocket (Primary): {"channelID":275,"channelName":"spread","event":"subscriptionStatus","pair":"XBT/USD","status":"subscribed","subscription":{"name":"spread"}} WebSocket (Backup): {"channelID":275,"channelName":"spread","event":"subscriptionStatus","pair":"XBT/USD","status":"subscribed","subscription":{"name":"spread"}} WebSocket (Primary): [275,["9674.90000","9675.00000","1591440118.120752","10.88476562","3.47935600"],"spread","XBT/USD"] WebSocket (Primary): {"event":"heartbeat"} WebSocket (Primary): {"event":"heartbeat"} WebSocket (Primary): [275,["9674.90000","9675.00000","1591440127.108830","10.98812533","3.47935600"],"spread","XBT/USD"] WebSocket (Primary): {"event":"heartbeat"} WebSocket (Primary): [275,["9674.90000","9675.00000","1591440129.406073","1.87412533","7.47935600"],"spread","XBT/USD"] WebSocket (Primary): [275,["9674.90000","9675.00000","1591440129.505372","0.77412533","7.47935600"],"spread","XBT/USD"] WebSocket (Primary): [275,["9674.90000","9675.00000","1591440129.572658","0.10335971","7.47935600"],"spread","XBT/USD"] WebSocket (Primary): [275,["9674.90000","9675.00000","1591440129.572658","0.10335971","7.47935600"],"spread","XBT/USD"] ^C WebSocket (Backup): [275,["9674.90000","9675.00000","1591440130.156840","0.10335971","8.27935600"],"spread","XBT/USD"] WebSocket (Backup): [275,["9674.90000","9675.00000","1591440130.195899","0.10335971","8.47435600"],"spread","XBT/USD"] WebSocket (Backup): [275,["9673.80000","9675.00000","1591440130.459388","0.10335971","8.47435600"],"spread","XBT/USD"] WebSocket (Backup): [275,["9672.60000","9675.00000","1591440130.195899","0.00516924","8.47435600"],"spread","XBT/USD"] WebSocket (Backup): [275,["9673.80000","9675.00000","1591440130.764856","0.00400000","8.47435600"],"spread","XBT/USD"] WebSocket (Backup): [275,["9673.80000","9674.90000","1591440130.780514","0.00400000","0.25000000"],"spread","XBT/USD"] WebSocket (Backup): {"event":"heartbeat"} WebSocket (Backup): [275,["9673.80000","9674.90000","1591440132.433940","4.00400000","0.25000000"],"spread","XBT/USD"] WebSocket (Backup): [275,["9673.80000","9674.90000","1591440132.519509","4.00000000","0.25000000"],"spread","XBT/USD"] WebSocket (Backup): [275,["9673.90000","9674.90000","1591440132.527887","0.10336612","0.25000000"],"spread","XBT/USD"] WebSocket (Backup): [275,["9673.90000","9675.00000","1591440132.527887","0.10336612","4.27935600"],"spread","XBT/USD"]
Notez que les connexions WebSocket redondantes sont la plus complexe des trois solutions, mais c'est la solution optimale en termes de fiabilité.