# Cloud Challenge- Using Redis and RDS. ### Improve perfomance using redis https://acloudguru.com/blog/engineering/cloudguruchallenge-improve-application-performance-using-amazon-elasticache ### For accomplish this issue I required: - a valid AWS profile - a valid KeyPair to be used in the EC2. ### Steps #### Implement RDS,VPC,EC2,REDIS using cdk ``` let vpc = new ec2.Vpc(this,'ChallengeVPC',{ cidr:'10.0.0.0/16', natGateways:1, maxAzs:2, subnetConfiguration: [ { cidrMask:24, name:'App', subnetType:ec2.SubnetType.PUBLIC }, { cidrMask:24, name:'Rds', subnetType:ec2.SubnetType.PRIVATE }, { cidrMask:24, name:'Cache', subnetType:ec2.SubnetType.PRIVATE } ] }); let subnetsForCluster = vpc.selectSubnets({ subnetGroupName:'Cache'}); let subnetsForRds = vpc.selectSubnets({subnetGroupName:'Rds'}); let ec2SG= new ec2.SecurityGroup(this,'ec2SG',{ vpc:vpc, allowAllOutbound:true }); const bastion = new BastionHostLinux(this,'bastion-id', { vpc: vpc, securityGroup: ec2SG, instanceName: 'instance-bastion', machineImage: new AmazonLinuxImage(), instanceType: InstanceType.of(InstanceClass.T3, InstanceSize.MICRO), subnetSelection: vpc.selectSubnets({subnetType: ec2.SubnetType.PUBLIC}) }); bastion.instance.instance.addPropertyOverride('KeyName', 'for-bastion'); let clusterSG= new ec2.SecurityGroup(this,'redisSG',{ vpc:vpc, securityGroupName:"Security group for REDIS" }); let rdsSG = new ec2.SecurityGroup(this,'rdsSG',{ vpc:vpc }); clusterSG.addIngressRule(ec2SG,ec2.Port.tcp(6579),'allow from ec2'); rdsSG.addIngressRule(ec2SG,ec2.Port.tcp(5432),'allow from ec2'); ec2SG.addIngressRule(Peer.anyIpv4(),ec2.Port.tcp(8080),'allow 8080 for public'); ec2SG.addIngressRule(Peer.anyIpv4(),ec2.Port.tcp(80),'allow 8080 for public'); ec2SG.addIngressRule(Peer.anyIpv4(),ec2.Port.tcp(22),'allow ssh from the world'); let subnetRDS = new rds.SubnetGroup(this,'subnet for rds',{ vpc: vpc, description:'rds for data', subnetGroupName:"subnet for rds", vpcSubnets: { subnets:subnetsForRds.subnets } }); let db = new rds.DatabaseInstance(this,'db-instance',{ vpc, engine:rds.DatabaseInstanceEngine.postgres({ version:rds.PostgresEngineVersion.VER_11 }), securityGroups:[rdsSG], subnetGroup:subnetRDS, instanceType: ec2.InstanceType.of(ec2.InstanceClass.BURSTABLE3, ec2.InstanceSize.MICRO), multiAz:false, databaseName:'dbname', //@ts-ignore credentials:rds.Credentials.fromPassword('administrator',SecretValue.plainText("paraguay")) }); let subnetGroupRedis: CfnSubnetGroup; // @ts-ignore subnetGroupRedis = new elastic.CfnSubnetGroup(this, "Redis subnetGroup", { cacheSubnetGroupName: "redis-private", subnetIds: subnetsForCluster.subnetIds, description: "Subnet para el redis" }); // @ts-ignore let redis = new elastic.CfnCacheCluster(this, 'Redis Cluster',{ engine:'redis', cacheNodeType:"cache.t2.micro", numCacheNodes:1, clusterName:"cluster-redis", vpcSecurityGroupIds:[clusterSG.securityGroupId], cacheSubnetGroupName:subnetGroupRedis.cacheSubnetGroupName, }); redis.addDependsOn(subnetGroupRedis); ``` #### Log by ssh Inside the public ec2: ssh ec2-user@34.xxx.xxx.xxx -i keys/for-bastion.pem install psycopg2,postgres,flask,parserconfig,redis #### Modifications to file [app.py] ``` # /usr/bin/python2.7 import psycopg2 from configparser import ConfigParser from flask import Flask, request, render_template, g, abort import time import redis def config(filename='config/database.ini', section='postgresql'): # create a parser parser = ConfigParser() # read config file parser.read(filename) # get section, default to postgresql db = {} if parser.has_section(section): params = parser.items(section) for param in params: db[param[0]] = param[1] else: raise Exception('Section {0} not found in the {1} file'.format(section, filename)) return db def fetch(sql): # connect to database listed in database.ini ttl = 10 # Time to live in seconds try: params = config(filename='config/database.ini',section='redis') cache = redis.Redis.from_url(params['redis_url']) result = cache.get(sql) if result: return result else: # connect to database listed in database.ini conn = connect() cur = conn.cursor() cur.execute(sql) # fetch one row result = cur.fetchone() print('Closing connection to database...') cur.close() conn.close() # cache result cache.setex(sql, ttl, ''.join(result)) return result except (Exception, psycopg2.DatabaseError) as error: print(error) def connect(): """ Connect to the PostgreSQL database server and return a cursor """ conn = None try: # read connection parameters params = config() # connect to the PostgreSQL server print('Connecting to the PostgreSQL database...') conn = psycopg2.connect(**params) except (Exception, psycopg2.DatabaseError) as error: print("Error:", error) conn = None else: # return a conn return conn app = Flask(__name__) @app.before_request def before_request(): g.request_start_time = time.time() g.request_time = lambda: "%.5fs" % (time.time() - g.request_start_time) @app.route("/") def index(): sql = 'SELECT slow_version();' db_result = fetch(sql) if(db_result): db_version = "".join([str(i) for i in db_result]) else: abort(500) params = config() return render_template('index.html', db_version = db_version, db_host = params['host']) if __name__ == "__main__": # on running python app.py app.run() # run the flask app ![FromFlask.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1627570193391/gtexPxq-_.png) ``` #### Modifications to config/database.ini ``` [postgresql] host=database-1.covqqx1gffj6.us-east-1.rds.amazonaws.com database=challenge user=challenge password=ACGChall3ng3 [redis] redis_url=redis://cluster-redis.6ddjjb.0001.use1.cache.amazonaws.com:6379 ``` We can see the response using the RDS response ![CallWebServerFlask.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1627570503194/f3OZ1yfcI.png) From the log of EC2 ![FromFlask.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1627570451586/Tzb8QLgzG.png) Response using redis ![Redis.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1627570539620/Mny8OQUXH.png) From the log,we can see that is not requesting the RDS ![RedisResponse.png](https://cdn.hashnode.com/res/hashnode/image/upload/v1627570563353/aHPjQo_J-.png)