Your First S2Graph

Once the S2Graph server has been set up, you can now start to send HTTP queries to the server to create a graph and pour data in it. This tutorial goes over a simple toy problem to get a sense of how S2Graph’s API looks like. For the exact definitions of the terminology used here, refer to The Data Model document. The toy problem is to create a timeline feature for a simple social media, like a simplified version of Facebook’s timeline. Using simple S2Graph queries it is possible to keep track of each user’s friends and their posts.

First, we need a name for the new service.

The following POST query will create a service named KakaoFavorites

curl -XPOST localhost:9000/admin/createService -H 'Content-Type: Application/json' -d '
{
  "serviceName": "KakaoFavorites",
  "compressionAlgorithm" : "gz"
}'

To make sure the service is created correctly, check out the following

curl -XGET localhost:9000/admin/getService/KakaoFavorites

Next, we will need some friends.

In S2Graph, relationships are organized as labels. Create a friends label with the following createLabel API call:

curl -XPOST localhost:9000/admin/createLabel -H 'Content-Type: Application/json' -d '
{
  "label": "friends",
  "srcServiceName": "KakaoFavorites",
  "srcColumnName": "userName",
  "srcColumnType": "string",
  "tgtServiceName": "KakaoFavorites",
  "tgtColumnName": "userName",
  "tgtColumnType": "string",
  "isDirected": "false",
  "indices": [],
  "props": [],
  "consistencyLevel": "strong"
}'

Check if the label has been created correctly:

curl -XGET localhost:9000/admin/getLabel/friends

Now that the label friends is ready, we can store the friendship data. Entries of a label are called edges, and you can add edges with edges/insert API:

curl -XPOST localhost:9000/mutate/edge/insert -H 'Content-Type: Application/json' -d '
[
   {"from":"Elmo","to":"Big Bird","label":"friends","props":{},"timestamp":1444360152477},
   {"from":"Elmo","to":"Ernie","label":"friends","props":{},"timestamp":1444360152478},
   {"from":"Elmo","to":"Bert","label":"friends","props":{},"timestamp":1444360152479},
   {"from":"Cookie Monster","to":"Grover","label":"friends","props":{},"timestamp":1444360152480},
   {"from":"Cookie Monster","to":"Kermit","label":"friends","props":{},"timestamp":1444360152481},
   {"from":"Cookie Monster","to":"Oscar","label":"friends","props":{},"timestamp":1444360152482}
]'

Query friends of Elmo with getEdges API:

curl -XPOST localhost:9000/graphs/getEdges -H 'Content-Type: Application/json' -d '
{
  "srcVertices": [{"serviceName": "KakaoFavorites", "columnName": "userName", "id":"Elmo"}],
  "steps": [
    {"step": [{"label": "friends", "direction": "out", "offset": 0, "limit": 10}]}
  ]
}'

Now query friends of Cookie Monster:

curl -XPOST localhost:9000/graphs/getEdges -H 'Content-Type: Application/json' -d '
{
  "srcVertices": [{"serviceName": "KakaoFavorites", "columnName": "userName", "id":"Cookie Monster"}],
  "steps": [
    {"step": [{"label": "friends", "direction": "out", "offset": 0, "limit": 10}]}
  ]
}'

Users of Kakao Favorites will be able to post URLs of their favorite websites.

We will need a new label post for this data:

curl -XPOST localhost:9000/admin/createLabel -H 'Content-Type: Application/json' -d '
{
  "label": "post",
  "srcServiceName": "KakaoFavorites",
  "srcColumnName": "userName",
  "srcColumnType": "string",
  "tgtServiceName": "KakaoFavorites",
  "tgtColumnName": "url",
  "tgtColumnType": "string",
  "isDirected": "true",
  "indices": [],
  "props": [],
  "consistencyLevel": "strong"
}'

Now, insert some posts of the users:

curl -XPOST localhost:9000/mutate/edge/insert -H 'Content-Type: Application/json' -d '
[
  {"from":"Big Bird","to":"www.kakaocorp.com/en/main","label":"post","props":{},"timestamp":1444360152477},
  {"from":"Big Bird","to":"github.com/kakao/s2graph","label":"post","props":{},"timestamp":1444360152478},
  {"from":"Ernie","to":"groups.google.com/forum/#!forum/s2graph","label":"post","props":{},"timestamp":1444360152479},
  {"from":"Grover","to":"hbase.apache.org/forum/#!forum/s2graph","label":"post","props":{},"timestamp":1444360152480},
  {"from":"Kermit","to":"www.playframework.com","label":"post","props":{},"timestamp":1444360152481},
  {"from":"Oscar","to":"www.scala-lang.org","label":"post","props":{},"timestamp":1444360152482}
]'

Query posts of Big Bird:

curl -XPOST localhost:9000/graphs/getEdges -H 'Content-Type: Application/json' -d '
{
  "srcVertices": [{"serviceName": "KakaoFavorites", "columnName": "userName", "id":"Big Bird"}],
  "steps": [
    {"step": [{"label": "post", "direction": "out", "offset": 0, "limit": 10}]}
  ]
}'

So far, we have designed a label schema for the labels friends and post, and stored some edges to them.

This should be enough for creating the timeline feature! The following two-step query will return the URLs for Elmo’s timeline, which are the posts of Elmo’s friends:

curl -XPOST localhost:9000/graphs/getEdges -H 'Content-Type: Application/json' -d '
{
  "srcVertices": [{"serviceName": "KakaoFavorites", "columnName": "userName", "id":"Elmo"}],
  "steps": [
    {"step": [{"label": "friends", "direction": "out", "offset": 0, "limit": 10}]},
    {"step": [{"label": "post", "direction": "out", "offset": 0, "limit": 10}]}
  ]
}'

Also try Cookie Monster’s timeline:

curl -XPOST localhost:9000/graphs/getEdges -H 'Content-Type: Application/json' -d '
{
  "srcVertices": [{"serviceName": "KakaoFavorites", "columnName": "userName", "id":"Cookie Monster"}],
  "steps": [
    {"step": [{"label": "friends", "direction": "out", "offset": 0, "limit": 10}]},
    {"step": [{"label": "post", "direction": "out", "offset": 0, "limit": 10}]}
  ]
}'

The example above is by no means a full blown social network timeline, but it gives you an idea of how to represent, store and query graph data with S2Graph.

We also provide a simple script under script/test.sh so that you can see if everything is setup correctly.

sh script/test.sh