Hands-on Lab: Amazon ElastiCache

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Getting Started with ElastiCache for Redis
Hands-on Lab
1. Create an Amazon EC2 t2.micro instance with Amazon Linux
 See documentation at
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EC2_GetStarted.html
 Create and use a securitygroup that allows inboundTCP access
using SSH (port 22) and MYSQL (port 3306) plus a custom rule
to allow access from Redis (port 6379)
You might get an automated warningthat your EC2 instance is
“open to the world”, because we’re not limiting the source
range for SSH. This is expected. In a production system, you’ll
want to provide a limited IP range for allowedSSH access. For
this lab, disregardthe warning.
 We’ll be accessingboth MySQL and Redis from this EC2
instance. Once the instance is created, go back to the security
group and update the “Source” for both services to use the IP
address of your EC2 instance.
2. Access the linux console. See documentation at
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/AccessingInstances.html
Use ssh for Linux or Mac; use PuTTY for Windows
Example:
ssh –i ~/Downloads/key.pem ec2-user@ec2-01-02-03-99.us-west-2.compute.amazonaws.com
[ec2-user@ip-192-168-0-1 ~]$
 Install MySql and Redis developmentclients
$ sudo yum install mysql-devel
$ sudo yum install gcc
$ sudo pip install MySQL-python
$ sudo pip install redis

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 Install Redis command line interface
$ sudo yum --enablerepo=epel install redis
3. Create an Amazon RDS MySQL db.t2.micro instance
http://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/CHAP_GettingStarted
.CreatingConnecting.MySQL.html
 Name the instance sql-lab. Be sure to choose MySQL (not
Aurora and not MariaDB) and the db.t2.micro instance size
 Choose a username and a password(and don’t forget them!)
 Do not create a database (we will do that later)e
 Once the instance is created, find your mysql node name
i. On the AWS Console, choose Services, then RDS

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ii. On the RDS dashboard, choose DB Instances

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iii. Select the ▶ next to your DB Instance
iv. Note your endpoint name. You will need it later!
When using the endpoint name, you usuallyshould not
use the port extension (:3306), just the name.
 Verifyyou can access the mysql> console from your EC2
instance
$ mysql –h <mysql node name> -u <user name> -p
Example:
$ mysql -h sql-lab.cxpjiluqq0c9.us-west-2.rds.amazonaws.com -u awsuser -p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or g.
Your MySQL connection id is 9999
Server version: 5.6.27-log MySQL Community Server (GPL)
Type 'help;' or 'h' for help. Type 'c' to clear the current input statement.
mysql>
To exit from the mysql> prompt, use CTRL-D
4. Create an Amazon ElastiCache cache.t2.micro instance with Redis

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http://docs.aws.amazon.com/AmazonElastiCache/latest/UserGuide/GettingStarte
d.html
 Name the instance redis-lab. Be sure to choose the
cache.t2.microinstance size
 Disable replication (justa single node)
 Once the instance is created, find your ElastiCache for Redis
node name
i. On the AWS Console, choose Services, then ElastiCache
ii. On the ElastiCache dashboard, choose Cache Clusters

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iii. Select the ▶ next to your Cache Cluster name, then click
on the Nodes
iv. Note your endpointname. You will need it later!
 Verifyyou can access the redis> console from your EC2 instance
$ redis-cli –h <redis node name>
Example:
$ $ redis-cli -h redis-lab.qwe34ytz.0001.usw2.cache.amazonaws.com
redis-lab.sjyq2g.0001.usw2.cache.amazonaws.com:6379>
To exit from the redis> prompt, use CTRL-D

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5. Downloadand Prepare Landsat scenes
https://aws.amazon.com/public-data-sets/landsat/
 From your EC2 instance, downloadthe Landsat scenes
$ wget http://landsat-pds.s3.amazonaws.com/scene_list.gz
 Unzipthe scene list
$ gunzip scene_list.gz
 Trim the list to the last 250,000 scenes
$ cp scene_list scene_list.orig
$ tail -n 250000 scene_list.orig > scene_list
6. Load to MySQL
 Log into the mysql> console
 Create a landsat database
mysql> CREATE DATABASE landsat;
mysql> USE landsat;
 Create the scene_listtable
mysql> CREATE TABLE scene_list (entityId VARCHAR(64), acquisitionDate
DATETIME,cloudCover DECIMAL(5,2),processingLevel VARCHAR(8),path
INT,row INT,min_lat DECIMAL(8,5),min_lon DECIMAL(8,5),max_lat
DECIMAL(8,5),max_lon DECIMAL(8,5),download_url VARCHAR(128));
 Load the landsat data
mysql> LOAD DATA LOCAL INFILE 'scene_list' INTO TABLE scene_list FIELDS
TERMINATED BY ',';

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7. Load to Redis
 Create the file sql2redis.py, containing the followingcode. Be sure
to replace items in red with your own endpoints, user name and
password.
#!/usr/bin/python
import redis
import MySQLdb
from collections import Counter
r = redis.StrictRedis('<your redis node>',port=6379,db=0)
database = MySQLdb.connect("<your MySQL node>","<your username>","<your
password>","landsat")
cursor = database.cursor()
select = 'SELECT entityId, UNIX_TIMESTAMP(acquisitionDate), cloudCover,
processingLevel, path, row, min_lat, min_lon, max_lat, max_lon, download_url FROM
scene_list'
cursor.execute(select)
data = cursor.fetchall()
for row in data:
r.hmset(row[0],{'acquisitionDate':row[1],'cloudCover':row[2],'processingLevel':row[
3],'path':row[4],'row':row[5],'min_lat':row[6],'min_lon':row[7],'max_lat':row[8],'max_
lon':row[9],'download_url':row[10]})
r.zadd('cCov',row[2],row[0])
r.zadd('acqDate',row[1],row[0])
cursor.close()
database.close()
 From the linux console, run the python script to cache data in
Redis
$ python sql2redis.py
o this will take a few minutes to run. To check progress, log
into your Redis node and run
redis> DBSIZE

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8. Run SQL query
 Log in to your MySQL node and run a query
mysql> SELECT DISTINCT(a.entityId) AS Id, a.cloudCover
FROM scene_list a
INNER JOIN (
SELECT entityId, acquisitionDate
FROM scene_list
WHERE acquisitionDate > (
SELECT MAX(acquisitionDate)
FROM scene_list
WHERE acquisitionDate < CURDATE() - INTERVAL 1 YEAR
)
) b ON a.entityId = b.entityId AND a.acquisitionDate = b.acquisitionDate
WHERE cloudCover < 50
ORDER BY Id;
 This generates a list of all the satellite images duringthe last year
which have less than 50% cloudcover
 Note how long it takes to get an answer
9. Run Redis query
 Log in to your Redis node and run
redis> zunionstore temp:cCov 1 cCov
redis> zremrangebyscore temp:cCov 50 inf
redis> zunionstore temp:acqDate 1 acqDate
redis> zremrangebyscore temp:acqDate 0 1465862400
redis> zinterstore out 2 temp:cCov temp:acqDate WEIGHTS 1 0
 Again, this generates a list of all the satellite images duringthe last
year which have less than 50% cloudcover
 Note how long it takes to get an answer

Hands-on Lab: Amazon ElastiCache

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