Manage Vertices (Optional)

Vertices are the two end points of an edge, and logically stored in columns of a service. If your use case requires storing metadata corresponding to vertices rather than edges, there are operations available on vertices as well.

Vertex Fields

Unlike edges and their labels, properties of a vertex are not indexed nor require a predefined schema. The following fields are used when operating on vertices.

Option

Field Name	Definition	Data Type	Example	Note
timestamp	Issue time of request	Long	1430116731156	Required. Unix Epoch time in milliseconds
operation	One of insert, delete, update, increment	String	i, insert	Required only for bulk operations. Alias are also available: i (insert), d (delete), u (update), in (increment). Default is insert.
serviceName	Corresponding service name	String	kakaotalk/kakaogroup	Required
columnName	Corresponding column name	String	user_id	Required
id	Unique identifier of vertex	Long/String	101	Required. Use Long if possible
props	Additional properties of vertex	JSON (dictionary)	{“is_active_user”: true, “age”:10, “gender”: “F”, “country_iso”: “kr”}	Required

Basic Vertex Operations

Insert - POST /mutate/vertex/insert/:serviceName/:columnName

curl -XPOST localhost:9000/mutate/vertex/insert/s2graph/account_id -H 'Content-Type: Application/json' -d '
[
  {"id":1,"props":{"is_active":true, "talk_user_id":10},"timestamp":1417616431000},
  {"id":2,"props":{"is_active":true, "talk_user_id":12},"timestamp":1417616431000},
  {"id":3,"props":{"is_active":false, "talk_user_id":13},"timestamp":1417616431000},
  {"id":4,"props":{"is_active":true, "talk_user_id":14},"timestamp":1417616431000},
  {"id":5,"props":{"is_active":true, "talk_user_id":15},"timestamp":1417616431000}
]'

Delete - POST /mutate/vertex/delete/:serviceName/:columnName

curl -XPOST localhost:9000/mutate/vertex/delete/s2graph/account_id -H 'Content-Type: Application/json' -d '
[
  {"id":1,"timestamp":1417616431001},
  {"id":2,"timestamp":1417616431002}
]'

This operation will delete only the vertex data of a specified column and will not delete any edges connected to those vertices. Also important thing is timestamp. vertex will be deleted only if delete requests timestamp is larger than all of vertexs property`s timestamp.

following example shows the difference.

curl -XPOST localhost:9000/mutate/vertex/insert/s2graph_test/account_id -H 'Content-Type: Application/json' -d '
[
  {"id":1,"props":{"is_active":true, "talk_user_id":10},"timestamp":1417616431000},
  {"id":1,"props":{"talk_user_id":20},"timestamp":1417616431002}
]'

if user request delete(ts) on vertex like below then vertex would not be deleted, but only properties on this vertex that is updated before ts will be deleted.

curl -XPOST localhost:9000/mutate/vertex/delete/s2graph_test/account_id -H 'Content-Type: Application/json' -d '
[
  {"id":1,"timestamp":1417616431001}
]'

then result still have vertex with property that is updated with larger timestamp.

curl -XPOST localhost:9000/graphs/getVertices -H 'Content-Type: Application/json' -d '
[
   {"serviceName": "s2graph_test", "columnName": "account_id", "ids": [1]}
]'


# result
{
  "serviceName": "s2graph_test",
  "columnName": "account_id",
  "id": 1,
  "props": {
    "talk_user_id": 20
  },
  "timestamp": 1417616431002
}

Important notes

Note

This means that edges returned by a query can contain deleted vertices. Clients are responsible for checking validity of the vertices.

Delete All - POST /mutate/vertex/deleteAll/:serviceName/:columnName

This is a very expensive operation. If you’re interested in what goes on under the hood, please refer to the following pseudocode:

vertices = vertex list to delete
  for vertex in vertices
      labels = fetch all labels that this vertex is included.
      for label in labels
          for index in label.indices
              edges = G.read with limit 50K
              for edge in edges
                  edge.delete

The total complexity is O(L L.I) reads + O(L L.I 50K) writes, worst case. If the vertex you’re trying to delete has more than 50K edges, the deletion will not be consistent.

Update - POST /mutate/vertex/insert/:serviceName/:columnName

Basically update on Vertex is same with insert overwrite so use insert for update.

Increment

Not yet implemented; stay tuned.