Merge pull request #31 from gofynd/enhancement/detail-api-retry-mechanism

Add retry mechanism in case of timeout has occurred when new cluster …

Author: brijeshgajjarfynd

CHANGELOG.md

@@ -5,6 +5,10 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
 
+---
+## [v0.6.0] - 2024-01-09
+### Added
+- Added retry mechanism for APIs getting used inside extension library if Fynd Platform server is down.
 ---
 ## [v0.5.4] - 2023-03-03
 ### Changed

express/constants.js

@@ -6,4 +6,7 @@ exports.ASSOCIATION_CRITERIA = {
     ALL: "ALL",
     SPECIFIC: "SPECIFIC-EVENTS", // to be set when saleschannel specific events are subscribed and sales channel present
     EMPTY: "EMPTY" // to be set when saleschannel specific events are subscribed but not sales channel present
-}
+}
+exports.TIMEOUT_STATUS = 504;
+exports.SERVICE_UNAVAILABLE = 503;
+exports.BAD_GATEWAY = 502;

express/extension.js

@@ -7,6 +7,7 @@ const { WebhookRegistry } = require('./webhook');
 const logger = require('./logger');
 const { fdkAxios } = require('@gofynd/fdk-client-javascript/sdk/common/AxiosHelper');
 const { version } = require('./../package.json');
+const { RetryManger } = require("./retry_manager")
 
 class Extension {
     constructor() {
@@ -19,11 +20,17 @@ class Extension {
         this.cluster = "https://api.fynd.com";
         this.webhookRegistry = null;
         this._isInitialized = false;
+        this._retryManager = new RetryManger();
     }
 
     async initialize(data) {
 
+        if (this._isInitialized) {
+            return;
+        }
+
         this._isInitialized = false;
+        this.configData = data;
 
         this.storage = data.storage;
 
@@ -50,22 +57,22 @@ class Extension {
             }
             this.cluster = data.cluster;
         }
-        this.webhookRegistry = new WebhookRegistry();
+        this.webhookRegistry = new WebhookRegistry(this._retryManager);
 
-        let extensionData = await this.getExtensionDetails();
+        await this.getExtensionDetails();
 
         if (data.base_url && !validator.isURL(data.base_url)) {
             throw new FdkInvalidExtensionConfig("Invalid base_url value. Invalid value: " + data.base_url);
         }
         else if (!data.base_url) {
-            data.base_url = extensionData.base_url;
+            data.base_url = this.extensionData.base_url;
         }
         this.base_url = data.base_url;
 
         if (data.scopes) {
-            data.scopes = this.verifyScopes(data.scopes, extensionData);
+            data.scopes = this.verifyScopes(data.scopes, this.extensionData);
         }
-        this.scopes = data.scopes || extensionData.scope;
+        this.scopes = data.scopes || this.extensionData.scope;
 
         logger.debug(`Extension initialized`);
 
@@ -96,9 +103,9 @@ class Extension {
         return this.access_mode === 'online';
     }
 
-    getPlatformConfig(companyId) {
+    async getPlatformConfig(companyId) {
         if (!this._isInitialized){
-            throw new FdkInvalidExtensionConfig('Extension not initialized due to invalid data')    
+            await this.initialize(this.configData);
         }
         let platformConfig = new PlatformConfig({
             companyId: parseInt(companyId),
@@ -113,11 +120,11 @@ class Extension {
 
     async getPlatformClient(companyId, session) {
         if (!this._isInitialized){
-            throw new FdkInvalidExtensionConfig('Extension not initialized due to invalid data')    
+            await this.initialize(this.configData);
         }
         const SessionStorage = require('./session/session_storage');
 
-        let platformConfig = this.getPlatformConfig(companyId);
+        let platformConfig = await this.getPlatformConfig(companyId);
         platformConfig.oauthClient.setToken(session);
         platformConfig.oauthClient.token_expires_at = session.access_token_validity;
 
@@ -140,14 +147,22 @@ class Extension {
     }
 
     async getExtensionDetails() {
+
+        let url = `${this.cluster}/service/panel/partners/v1.0/extensions/details/${this.api_key}`;
+        const uniqueKey = `${url}`;
+
+        const retryInfo = this._retryManager.retryInfoMap.get(uniqueKey);
+        if (retryInfo && !retryInfo.isRetry) {
+            this._retryManager.resetRetryState(uniqueKey);
+        }
+
         try {
-            let url = `${this.cluster}/service/panel/partners/v1.0/extensions/details/${this.api_key}`;
             const token = Buffer.from(
                 `${this.api_key}:${this.api_secret}`,
                 "utf8"
             ).toString("base64");
             const rawRequest = {
-                method: "get",
+                method: "GET",
                 url: url,
                 headers: {
                     Authorization: `Basic ${token}`,
@@ -157,8 +172,17 @@ class Extension {
             };
             let extensionData = await fdkAxios.request(rawRequest);
             logger.debug(`Extension details received: ${logger.safeStringify(extensionData)}`);
-            return extensionData;
+            this.extensionData = extensionData;
         } catch (err) {
+
+            if (
+                RetryManger.shouldRetryOnError(err) 
+                && !this._retryManager.isRetryInProgress(uniqueKey)
+            ) { 
+                logger.debug(`API call failed. Starting retry for ${uniqueKey}`)
+                return await this._retryManager.retry(uniqueKey, this.getExtensionDetails.bind(this));
+            }
+
             throw new FdkInvalidExtensionConfig("Invalid api_key or api_secret. Reason:" + err.message);
         }
     }

express/retry_manager.js

@@ -0,0 +1,116 @@
+const { BAD_GATEWAY, SERVICE_UNAVAILABLE, TIMEOUT_STATUS } = require("./constants");
+const logger = require('./logger');
+
+
+/**
+ * @typedef {Object} RetryInfo
+ * @property {boolean} isRetryInProgress
+ * @property {boolean} isRetry
+ * @property {number} retryCount
+ * @property {NodeJS.Timeout | null} retryTimer
+ * @property {function} fn
+ * @property {any[]} args
+ */
+
+/**
+ * @typedef {Map<string, RetryInfo>} RetryInfoMap
+ */
+
+class RetryManger {
+
+  constructor() {
+    /**
+     * @type {RetryInfoMap}
+     */
+    this.retryInfoMap = new Map();
+  }
+
+  static shouldRetryOnError(err) {
+    const statusCode = (err.response && err.response.status) || err.code; 
+    return [BAD_GATEWAY, SERVICE_UNAVAILABLE, TIMEOUT_STATUS].includes(statusCode)
+  }
+
+
+  async retry(uniqueKey, fn, ...args) {
+
+    if (!this.retryInfoMap.has(uniqueKey)) {
+      this.retryInfoMap.set(uniqueKey, {
+        fn: fn,
+        args: args,
+        retryCount: 0,
+        retryTimer: null,
+        isRetryInProgress: false
+      })
+    }
+
+    const retryInfo = this.retryInfoMap.get(uniqueKey);
+
+    retryInfo.isRetryInProgress = true;
+    retryInfo.retryCount++;
+
+    await (new Promise((resolve, reject) => {
+      retryInfo.retryTimer = setTimeout(resolve, this._getNextRetrySeconds(retryInfo.retryCount));
+    }))
+
+    return await this._makeRetry(uniqueKey);
+  }
+
+
+  _getNextRetrySeconds(retryCount) {
+    let nextRetrySeconds = 30 * 1000; // 30 seconds
+
+    if (retryCount > 3) {
+      const MAX_MINUTES_TO_WAIT = 3;
+      const MINUTES_TO_WAIT = Math.min((retryCount - 3), MAX_MINUTES_TO_WAIT);
+      nextRetrySeconds = 1000 * 60 * MINUTES_TO_WAIT;
+    }
+
+    return nextRetrySeconds;
+  }
+
+
+
+  async _makeRetry(uniqueKey) {
+
+    const retryInfo = this.retryInfoMap.get(uniqueKey);
+
+    clearTimeout(retryInfo.retryTimer);
+
+    try {
+      logger.debug(`Retrying api call for ${uniqueKey}. count: ${retryInfo.retryCount}`);
+      retryInfo.isRetry = true;
+      const data = await retryInfo.fn(...retryInfo.args);
+      logger.debug(`api call succeeded. stopping retry for ${uniqueKey}`);
+      this.resetRetryState(uniqueKey);
+      return data;
+
+    } catch(error) {
+      retryInfo.isRetry = false;
+      logger.debug(`API call failed on retry ${retryInfo.retryCount}: ${error.message}`);
+      return await this.retry(uniqueKey, retryInfo.fn, ...retryInfo.args);
+
+    }
+  }
+
+
+  resetRetryState(uniqueKey) {
+
+    const retryInfo = this.retryInfoMap.get(uniqueKey);
+
+    if (retryInfo.retryTimer) {
+      clearTimeout(retryInfo.retryTimer);
+    }
+
+    retryInfo.isRetry = false;
+    retryInfo.isRetryInProgress = false;
+    retryInfo.retryCount = 0;
+  }
+
+  isRetryInProgress(uniqueKey) {
+    return this.retryInfoMap.get(uniqueKey)? this.retryInfoMap.get(uniqueKey).isRetryInProgress: false;
+  }
+}
+
+module.exports = {
+  RetryManger
+}

express/routes.js

@@ -19,7 +19,7 @@ function setupRoutes(ext) {
         // ?company_id=1&client_id=123313112122
         try {
             let companyId = parseInt(req.query.company_id);
-            let platformConfig = ext.getPlatformConfig(companyId);
+            let platformConfig = await ext.getPlatformConfig(companyId);
             let session;
 
             session = new Session(Session.generateSessionId(true));
@@ -88,7 +88,7 @@ function setupRoutes(ext) {
             }
             const companyId = req.fdkSession.company_id
 
-            const platformConfig = ext.getPlatformConfig(req.fdkSession.company_id);
+            const platformConfig = await ext.getPlatformConfig(req.fdkSession.company_id);
             await platformConfig.oauthClient.verifyCallback(req.query);
 
             let token = platformConfig.oauthClient.raw_token;
@@ -161,7 +161,7 @@ function setupRoutes(ext) {
 
             logger.debug(`Extension auto install started for company: ${company_id} on company creation.`);
 
-            let platformConfig = ext.getPlatformConfig(company_id);
+            let platformConfig = await ext.getPlatformConfig(company_id);
             let sid = Session.generateSessionId(false, {
                 cluster: ext.cluster,
                 companyId: company_id