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Host your own PancakeSwap Testnet

July 17, 2021July 17, 2021nhancvLeave a Comment

https://github.com/nhancv/pancake-swap-testnet#readme Preparing source Clone pancake-swap-core Clone pancake-swap-periphery Clone pancake-swap-interface-v1 Setup Install contract merger: https://www.npmjs.com/package/sol-merger Prepare PancakeFactory and PancakeRouter01 Deploy PancakeFactory and PancakeRouter01 Access: https://remix.ethereum.org/#optimize=false&runs=200&evmVersion=null&version=soljson-v0.5.16+commit.9c3226ce.js Deploy WBNB New File: WBNB.sol => Copy source from https://gist.github.com/nhancv/b0b35f16472e4998d0fd17b7a1e4f707 Compiler tab => Select compiler: v0.8.3+commit.8d00100c Deploy tab…

Install Zabbix – Server Monitor

July 6, 2021July 6, 2021nhancvLeave a Comment

Config Server Install here: https://www.zabbix.com/download?zabbix=5.4&os_distribution=ubuntu&os_version=20.04_focal&db=postgresql&ws=nginx Config server: Config frontend web Restart server Setup Agent Access to vps agent -> Install zabbix-agent Public agent Restart agent Add host to Server Access…

Smart contract pagination for list

June 28, 2021June 28, 2021nhancvLeave a Comment

A contract has an infinite internal storage There are 2 limits to practicality: gas costs and the block gas limit. Example Create 5k5 players, read one time https://testnet.bscscan.com/address/0x721ff9e58831b698efd26b9ac744cf8f0aaecbc2#readContract Max Gas Limit is 28,500,000 at…

MongoDB Replica Setup

June 28, 2021June 29, 2021nhancvLeave a Comment

Setup MongoDB Controls Config replica Option 1: Use separate 3 vps – 3 instances mongod Option 2: (For test) Use 1 vps and create 3 instances mongod with difference db…

Node App with PM2 Cluster

June 28, 2021June 28, 2021nhancvLeave a Comment

https://pm2.keymetrics.io/docs/usage/cluster-mode/ Make sure your application is stateless: share database/cache, cronjob Create ecosystem.config.js at root

Nginx HTTP load balancer

June 28, 2021June 28, 2021nhancvLeave a Comment

Config Simple config: nginx.conf Health check: https://docs.nginx.com/nginx/admin-guide/load-balancer/http-health-check/ Monitoring: https://docs.nginx.com/nginx/admin-guide/monitoring/live-activity-monitoring/

Web stress test with jmeter

June 28, 2021nhancvLeave a Comment

Download https://jmeter.apache.org/download_jmeter.cgi Get started https://jmeter.apache.org/usermanual/get-started.html INSTRUCTION Download jmeter -> extract PREPARE TEST PLAN open terminal run GUI ./bin/jmeter Create new Test Plan Right click on “Test Plan” -> Add -> Threads -> Thread…

Flutter: Uplifting — Daily Routines, Rituals & Self-Control

June 28, 2021June 28, 2021nhancvLeave a Comment

Store + Android: https://play.google.com/store/apps/details?id=com.app.habitapp + iOS: https://apps.apple.com/us/app/uplifting-routine-rituals-app/id1541317887 Task list with reminders and timer. Develop positive habits, live a happier life. Uplifting keeps you organized by managing your routines and daily habits. We…

SmartContract ICO Crowdsale simple

May 5, 2021May 5, 2021nhancvLeave a Comment

Please read this post first: Issue your ERC20 token with Solidity on Ethereum Blockchain [https://medium.com/p/6e640eb613ff] Similar with ERC20 token, now let create a ICO Crowdsale with simple abstract: Start date…

Voting Application using Smart Contract

May 5, 2021May 5, 2021nhancvLeave a Comment

Please read some useful posts first: Issue your ERC20 token with Solidity on Ethereum Blockchain [https://medium.com/p/6e640eb613ff] SmartContract ICO Crowdsale simple [https://medium.com/p/35dc5ff02459] In this demo, I use web3 version 1.0.0-beta.33, solidity…