This application is built using -- Aerospike + Express + Angular + Node -- ASEAN (/a-shawn/) Stack.
The purpose of this sample application is to show that Aerospike data structures on top of a key-value store are an effective way to write applications with Aerospike as the only database. To demonstrate, this sample describes the design and implementation of a twitter-like application.
The code is easy to follow and substantial enough to be a foundation in learning how to leverage Aerospike's technology and it can also be used as a "seed" application that you can expand.
- Register | Login | Logout
- Post — similar to tweets, only better since there's no character limit :)
- Follow — follow other users
- Unfollow — unfollow users you are following
- Following — list of users you follow including their posts
- Followers — list of users that follow you including their posts
- Alerts — real-time alerts when users you are following add new posts
- Aerospike Server
- Aerospike Node.js Client
- Aerospike Server – The server should be running and accessible from this app.
To build the application and resolve dependencies, run command: npm install
In aerospike_config.js, update aerospikeCluster and aerospikeClusterPort such that it points to your instance running Aerospike Server.
To run the application, run command: node server
You should see message Connection to Aerospike cluster succeeded!
If you see Connection to Aerospike cluster failed!, please make sure your instance of Aerospike Server is running and available. Also confirm that aerospikeCluster and aerospikeClusterPort are set correctly as described above in the Config section.
If all is well, open web browser and point it to: http://localhost:9000
Key: uid
Bins:
- uid - String
- username - String
- password - String
- auth - String
Sample Record:
{ ns: 'test', set: 'users', key: 'dash' }
{ uid: 'dash',
username: 'dash',
password: 'dash',
auth: 'c18d1b9a-19fb-4b2b-b4d3-560c8af07ef6' }
Note: For simplicity password is stored in plain-text
Key: "uid:<uid>:tweets"
Bin:
- tweets - Array of Objects
Sample Record:
{ ns: 'test', set: 'tweets', key: 'uid:dash:tweets' }
{ tweets:
[ { tweet: 'Hello Portland!', ts: '2014-07-01T05:49:47.367Z' },
{ tweet: 'So hot today!', ts: '2014-07-01T05:39:38.136Z' },
{ tweet: 'Hi', ts: '2014-07-01T05:36:04.055Z' } ] }
Key: "uid:<uid>:followers"
Bin:
- followers - Array of Strings (usernames)
Sample Record:
{ ns: 'test', set: 'followers', key: 'uid:dash:followers’ }
{ followers:
[ 'joe',
'jane',
'moe',
'homer',
'peter'] }
Key: "uid:<uid>:following"
Bin:
- following - Array of Objects
Sample Record:
{ ns: 'test', set: 'following', key: 'uid:dash:following' }
{ following:
[ { tweets: [], handle: 'claire' },
{ tweets: [], handle: 'brandon' },
{ tweets: [], handle: 'donovan' },
{ tweets: [], handle: 'mary' },
{ tweets: [], handle: 'mike' },
{ tweets: [], handle: 'eva' },
{ tweets: [], handle: 'mark' }] }
Note: The empty tweets array gets populated on-demand in the client when user clicks / wants to see the tweets for a given user.
Enforces unique usernames
- Requires username and password
- Adds key-value to look up uid based on username:<username> as key
- Adds key-value to look up password based on uid:<username>:password as key
- Adds key-value to look up auth based on uid:<username>:auth as key
- Check for username:<username> key
* If it does not exist, username entered is invalid
* If it exists, check for uid:<username>:password key
- If it does not exist, password entered is invalid
- If it exists, compare password entered with password value stored in the bin accessed via uid:<username>:password key
- If passwords match:
- Look up auth based on uid:<username>:auth as key
- Store auth in HTML5 Web/Local Storage
- This value is used to check if user is logged in when browsing to various pages within the app. If this value is not found, user is routed back to Login
- This value is cleared when user Logs out
- Log user in
- Adds new object (tweet/post and timestamp) to array of objects stored and accessed via uid:<uid>:tweets key
- Adds new object (tweets/posts array and handle of user-to-follow) to array of objects stored and accessed via uid:<uid-of-current-user>:following key for the current user
- Retrieves followers (array accessed via uid:<uid-of-user-to-follow>:followers key) of user-to-follow user and adds current user as a follower
- Removes object (tweets/posts array and handle of user-to-unfollow) from array of objects stored and accessed via uid:<uid-of-current-user>:following key for the current user
- Retrieves followers (array accessed via uid:<uid-of-user-to-unfollow>:followers key) of user-to-unfollow user and removes current user as a follower
- Shows a list of users that current user is following
- On initial load, only the list of
followingusers is retrieved using uid:<uid-of-current-user>:following key - The tweets/posts of
followingusers are retrieved on-demand when user clicks on their row
- Shows a list of users that are following current user
- On initial load, only the list of
followersusers is retrieved using uid:<uid-of-current-user>:followers key - The tweets/posts of
followersusers are retrieved on-demand when user clicks on their row
- The technology used in this app to deliver real-time alerts is Socket.io
- The app is setup to listen for
tweetevent -- which is triggered when a new tweet/post gets added by a user. The object sent as a message to Socket.io client emit API looks like{uid: uid, tweet: tweetText} - Upon receiving a
tweetevent it then gets emitted out (in our case as abroadcastevent) to the connected clients along with data object{uid: uid, tweet: tweetText}it received - Individual clients are setup to listen on
socket:broadcastevent emitted as described above -- here the listener loops through users that the current user is following and if one of the users’ uid matches that of the data object it received{uid: uid, tweet: tweetText}, an alert is displayed
- Clears out auth stored in HTML5 Web/Local Storage and routes the user back to Login