WarmUpActivity.md

riak-lab

This activity assumes the driver being used is python, but there are drivers for many languages and instructions found here

Connecting to Riak

Basho's reference

import riak
my_client = riak.RiakClient(pb_port=8087)

Short Example

Suppose we want to mimic craigslist. There are a list of ads. Each ad has a description, date, author. Each author has a username, and name.

Consider how we would model that in Riak. We could think about this similarly to redis and make several maps.

author: {
  "username": username,
  "name": name
}

Then we simply need a reference to the author map in our ad map which gives us this sort of structure

ad: {
  "description": desc,
  "date": date,
  "author": author
}

Let's see what this would look like:

First create a bucket, we'll use this to store all of our ad objects

ads_bucket = my_client.bucket('ads')

We can then represent a single ad the following way

ad1 = ads_bucket.new('ad1')
ad1.registers['description'].assign('some description')
ad1.registers['data'].assign('some data')
ad1.registers['author'].assign('some author')
ad1.store()

Then you can do a loop and go through all the ads in a given list. Now that the database has a list of all the ads, Consider setting a flag if the ad was answered.

For instance let's say ad1 has been answered we could just do

ad.flags['answered'].enable()
ad.store()

Then, if we wanted to count how many times someone has requested an ad we could store a counter

ad.counters['viewed'].increment()
ad.store()

We can mirror all of these activities for sets. We would just have to change the bucket type.

To store the user's info, we can do

user_bucket = my_client.bucket('users')

users = users_bucket.new('user')
users.add('user1') # Now we have a set containing a user1

userinfo_bucket = my_client.bucket('user_info')
user1 = userinfo_bucket.new('user1')
user1.register['name'].assign('some name')
user1.register['username'].assign('some username')

Now we have a map containing a user's info that is stored in the user's set.

Next, we will query on user to find all ads this user created.

The first thing you need to do is create a detail bucket to store the relation between user and ads.

user1 = userinfo_bucket.get('user1').data # Get all info about user1
ad1 = ads_bucket.get('ad1').data # Get all info about ad1
username = user1['username']

ads_detail_bucket = my_client.bucket('adsDetail') # Create a new bucket to store ads detail

detail1 = ads_detail.new(username)
detail1.registers['ads'].assign(ad1)
detail1.store()

Then to query for the ads created by user1, we can do:

result = ads_detail_bucket.get('user1').data

print(result['ads'])