WebSocket API v1 - बाज़ार डेटा फ़ीड से अप्रत्याशित डिस्कनेक्शन

क्लाउडफ्लेयर की सुरक्षा सावधानियां अक्सर विशिष्ट IP पतों, समान IP पतों के समूहों (जैसे क्लास C ब्लॉक) या कुछ भौगोलिक स्थानों पर लागू होती हैं, इसलिए अपना IP पता बदलना कभी-कभी एक सरल लेकिन प्रभावी समाधान होता है।

उदाहरण के लिए, अपने API सॉफ़्टवेयर को किसी भिन्न AWS क्षेत्र में होस्ट करना या किसी भिन्न भौगोलिक स्थान पर VPN का उपयोग करना, दोनों ही स्थानीय IP पते को महत्वपूर्ण रूप से बदल देंगे और संभावित रूप से अप्रत्याशित डिस्कनेक्शन समस्या को हल कर देंगे।

एकल वेबसॉकेट कनेक्शन का उपयोग करना, जिसकी किसी भी अनपेक्षित डिस्कनेक्शन के लिए निगरानी की जाती है और आवश्यकतानुसार फिर से कनेक्ट और पुनः सब्सक्राइब किया जाता है, एक और सरल लेकिन प्रभावी समाधान है। निम्नलिखित एक बुनियादी उदाहरण Python कोड है जो दिखाता है कि जब भी एक WebSocketConnectionClosed अपवाद फेंका जाता है तो वेबसॉकेट कनेक्शन को कैसे फिर से कनेक्ट और पुनः सब्सक्राइब किया जाए:

#!/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)

जैसा कि निम्नलिखित नमूना आउटपुट में दिखाया गया है, वेबसॉकेट कनेक्शन और सदस्यता तब नवीनीकृत हो जाती है जब कनेक्शन अप्रत्याशित रूप से समाप्त हो जाता है (लूप के 30 और 60 पुनरावृत्तियों पर):

{"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"] ...

कई (दो या अधिक) अनावश्यक वेबसॉकेट कनेक्शन का उपयोग करना अप्रत्याशित वेबसॉकेट डिस्कनेक्शन का सबसे प्रभावी समाधान है, क्योंकि यह बाज़ार डेटा फ़ीड को बिना किसी रुकावट के जारी रखने की अनुमति देता है, भले ही अंतर्निहित कनेक्शन कितनी बार समाप्त हो जाएं।

निम्नलिखित बुनियादी उदाहरण Python कोड दिखाता है कि स्वचालित फ़ेलओवर के साथ कई वेबसॉकेट कनेक्शन कैसे लागू करें:

#!/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)

उपरोक्त कोड दो वेबसॉकेट कनेक्शन बनाता है और दोनों कनेक्शनों को एक ही बाज़ार डेटा फ़ीड की सदस्यता देता है। प्राथमिक कनेक्शन का उपयोग बाज़ार डेटा आउटपुट करने के लिए किया जाता है, जब तक कि कीबोर्ड इंटरप्ट (उदाहरण के लिए, Ctrl+C के माध्यम से) उत्पन्न नहीं होता है, जो प्राथमिक कनेक्शन को बंद कर देता है। प्राथमिक कनेक्शन से बाद के रीड एक अपवाद फेंकते हैं, जिसे पकड़ा जाता है और बाज़ार डेटा स्रोत को बैकअप कनेक्शन में बदलने के लिए उपयोग किया जाता है, जिसका उपयोग तब बाज़ार डेटा आउटपुट करने के लिए किया जाता है।

निम्नलिखित नमूना आउटपुट दिखाता है कि बाज़ार डेटा फ़ीड को बाधित किए बिना प्राथमिक कनेक्शन से बैकअप कनेक्शन में बाज़ार डेटा स्रोत कैसे बदलता है:

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"]

ध्यान दें कि अनावश्यक वेबसॉकेट कनेक्शन तीनों समाधानों में सबसे जटिल है, लेकिन विश्वसनीयता के संबंध में यह इष्टतम समाधान है।