Redis connection in node js

 import redis from 'redis';

// Create a Redis client with retry strategy const client = redis.createClient({ host: 'localhost', // Replace with your Redis server host port: 6379, // Replace with your Redis server port retry_strategy: function (options) { if (options.error && options.error.code === 'ECONNREFUSED') { // End reconnecting on a specific error and flush all commands with a individual error console.error('The server refused the connection'); return new Error('The server refused the connection'); } if (options.total_retry_time > 1000 * 60 * 60) { // End reconnecting after a specific timeout and flush all commands with a individual error console.error('Retry time exhausted'); return new Error('Retry time exhausted'); } if (options.attempt > 10) { // End reconnecting with built in error console.error('Too many retry attempts'); return undefined; } // Reconnect after a specific time return Math.min(options.attempt * 100, 3000); } }); client.on('connect', function() { console.log('Redis client connected'); }); client.on('error', function (err) { console.error('Something went wrong ' + err); }); export default client;

Clear cache || FlushDB || Clear Redis Cache ||Node js ||aws

Clear cache || FlushDB || Clear Redis Cache ||Node js ||aws 

const express = require('express');

const redis = require('redis'); const app = express(); const port = 3000; // Replace with your actual hostname and port const client = redis.createClient({ host: 'your-elasticache-hostname', port: your-elasticache-port }); client.on('error', (err) => { console.log("Error " + err); }); app.get('/flushall', (req, res) => { client.flushdb((err, succeeded) => { if (err) { res.status(500).send({ error: 'Failed to flush Redis cache' }); } else { res.send({ message: 'Redis cache successfully flushed' }); } }); }); app.listen(port, () => { console.log(`App running on port ${port}`); });

===============================

Method 2: with lamda 

const Redis = require('ioredis'); exports.handler = async (event, context) => { const redis = new Redis({ host: 'YOUR_REDIS_HOST', // replace with your host port: YOUR_REDIS_PORT, // replace with your port password: 'YOUR_REDIS_PASSWORD', // replace with your password (if any) db: 0, }); try { // Ping Redis to check connection const ping = await redis.ping(); console.log('Ping:', ping); // Clear all keys await redis.flushdb(); console.log('Cache cleared'); return { statusCode: 200, body: 'Cache cleared' }; } catch (error) { console.log('Error:', error); return { statusCode: 500, body: 'Error clearing cache' }; } finally { // Disconnect from Redis await redis.quit(); } };

=============================================

Methos 3: with redis dependency: const redis = require('redis'); exports.handler = async (event, context) => { return new Promise((resolve, reject) => { const client = redis.createClient({ host: 'YOUR_REDIS_HOST', // replace with your host port: YOUR_REDIS_PORT, // replace with your port password: 'YOUR_REDIS_PASSWORD', // replace with your password (if any) db: 0, }); client.on('connect', function() { console.log('Connected to Redis'); client.flushdb(function (err, succeeded) { if (err) { console.error('Error:', err); reject({ statusCode: 500, body: 'Error clearing cache' }); } else { console.log('Cache cleared'); resolve({ statusCode: 200, body: 'Cache cleared' }); } // Disconnect from Redis client.quit(); }); }); client.on('error', function (err) { console.error('Error:', err); reject({ statusCode: 500, body: 'Error clearing cache' }); }); }); };

Calculate your Age

Calculate Age

Age Calculator

Enter your Date of Birth(mm/dd/yyyy) :

what is meant by --max-request-journal-entries and --no-request-journal in wiremock configuration

max-request-journal-entries and no-request-journal in wiremock configuration

In WireMock, the request journal is a built-in feature that keeps a record of incoming requests and their corresponding responses. It can be helpful for debugging and analysis purposes.

--max-request-journal-entries is an option that allows you to set a limit on the number of requests that the request journal stores. When this limit is reached, older requests will be removed from the journal to make room for new ones. By setting this option, you can control the memory usage of the request journal.

For example, using --max-request-journal-entries=10000 will limit the request journal to store a maximum of 10,000 requests.

--no-request-journal is an option that disables the request journal entirely. When this option is used, WireMock will not store any requests or responses in the request journal. Disabling the request journal can help reduce memory consumption and improve performance, especially during load testing or in production environments where request logging is not necessary.

In summary:

--max-request-journal-entries: Sets a limit on the number of requests stored in the request journal.

--no-request-journal: Disables the request journal completely.

Sort an array of 0s, 1s and 2s | Dutch National Flag problem

Sort an array of 0s, 1s and 2s |

Dutch National Flag problem

👀👀👀👀👀

/*

* This program defines a sortArray() method that sorts

* an array of 0s, 1s, and 2s using

* the Dutch National Flag algorithm.

*/

public class Sort012 {

public static void swap(int[] arr,int i,int j) {

int temp;

temp=arr[i];

arr[i]=arr[j];

arr[j]=temp;

}

public static void sortArray(int[] arr) {

int low =0;

int mid =0;

int high =arr.length-1;

while(mid<=high) {

switch (arr[mid]) {

case 0:

swap(arr,low,mid);

low++;

mid++;

break;

case 1:

mid++;

break;

case 2:

swap(arr,mid,high);

high--;

break;

default:

break;

}

}

}

public static void main(String... aa) {

int arr[]= {2,0,1,0,2,1,2,0,1,0,2,1};

sortArray(arr);

for(int i:arr) {

System.out.print(i+" ");

}

}

}

Output:

0 0 0 0 1 1 1 1 2 2 2 2

Merge two sorted linked lists

public class MergeLinkedLists {

static class ListNode {

int val;

ListNode next;

public ListNode() {}

public ListNode(int val) {

this.val = val;

}

public ListNode(int val, ListNode next) {

this.val = val;

this.next = next;

}

}

public static ListNode mergeTwoLists(ListNode list1, ListNode list2) {

ListNode mergedList = new ListNode();

ListNode current = mergedList;

while (list1 != null && list2 != null) {

if (list1.val <= list2.val) {

current.next = list1;

list1 = list1.next;

} else {

current.next = list2;

list2 = list2.next;

}

current = current.next;

}

if (list1 != null) {

current.next = list1;

} else {

current.next = list2;

}

return mergedList.next;

}

public static void main(String[] args) {

// Example usage:

ListNode list1 = new ListNode(1, new ListNode(2, new ListNode(4)));

ListNode list2 = new ListNode(1, new ListNode(3, new ListNode(4)));

ListNode mergedList = mergeTwoLists(list1, list2);

while (mergedList != null) {

System.out.print(mergedList.val + " ");

mergedList = mergedList.next;

}

}

}

Time Complexity: O(M + N), Where M and N are the size of the list1 and list2 respectively.
Auxiliary Space: O(M+N), Function call stack space

Output:

1 1 2 3 4 4

Geeks link:

    Merge To Linked List

Python script to automate login and extract cookie

 pip install requests

*****************create file*****************

import requests

url_login = "https://example.com/login" # Replace with the actual login URL url_after_login = "https://example.com/next" # Replace with the actual URL after login # Replace with your actual username and password payload = { "username": "your_username", "password": "your_password" } # Create a session to persist cookies session = requests.Session() # Perform the login response_login = session.post(url_login, data=payload) # Check if login was successful (replace '200' with the appropriate success status code) if response_login.status_code == 200: print("Login successful") # Perform the action after login (e.g., skip OTP) response_after_login = session.get(url_after_login) # Get the value of the desired cookie (replace 'cookie_name' with the actual cookie name) cookie_value = session.cookies.get("cookie_name") if cookie_value: print(f"The value of the cookie is: {cookie_value}") else: print("The desired cookie was not found.") else: print("Login failed.")

**********************************************

save login_script.py

python login_script.py