In this chapter, we describe the basic matters required when to use the Servwatch API.

Glossary

Device

Device means the barematal server or cloud instances.
The device basically manually activated, but it is also possible to activate automatically.
Requires there to map the device to the channel in any case.

Manual create
Case:Create from Management Console.
Automatically create
Case:When you connect the device for the first time in Servwatch.

The contents of the device can be obtained by the device service

Channel

Channel is a logical channel that stores the data transmitted from the device.
It is not to specify the channel directly from the device, you will be distributed from the device_id(device's serial).
Channel is a timeseries database with schema less JSON objects, each stream can be specified labels and units.

The contents of the device can be obtained by the channel service

Metrics

Metrics are various performance data sent by the device (server). (Example: CPU idle)

The data format must be written in JSON object format.

Metrics are stored for each channel ID mapped to the device.

The metrics can be obtained by the Stream service

Using API

The device (server) and Servmetry communicate using the MQTT protocol, and the application and Servmetry use the HTTP (S) protocol.

The REST API (HTTP / HTTPS protocol) is called by the application to manage devices and read metrics.

The following APIs are available depending on the application.

Device service:manage devices,channel assign,activate
Channel service:manage channel
Stream service:Retrieve metrics
Event service:manage threshold and notification
User service:manage user profile

API versioning

API version is specified in endpoint URI.(e.g. https://m.thingscale.io/v2/<SERVICE_NAME>)

Current API version and release note are here: Release Note

Security

All communication with ThingScale is performed over https(HTTP over TLS).
This ensures that all communication between ThingScale and device is over an encrypted communication.
HTTP/MQTT device connector can use plain-http and non-encrypted TCP communication for small memory footprint MCUs.(MCU:Micro Control Unit)
HTTP/HTTPS both protocols have pros and cons, choosing the right one depend on your environment and security trade-off.

We STRONGLY RECOMMENDED HTTPS/MQTTS for secure connection.

Protocol	Security	Resource requirement for devices
HTTP/MQTT	Poor(Non-encryption)	Low
HTTPS/MQTTS	Excellent(Avoid men-in-middle attack)	High(Use more memory and CPU cycles..)

Token

Tokens are per-user unique authorize key for API/Device connector.
In all cases you want to use the API token, it is strongly recommended that you use the HTTPS(TLS) connection.

API Token
All RESTful API operation use API token.
Device Token
For use only data sending from device to ThingScale with HTTP/MQTT connector.

NOTE

Device token is not per-device, per-user. Reason as in order to reduce the configuration task at the time of device distribution.

fig.2 Token overview

トークンの役割：

Token type:	REST API	HTTP/MQTT connector
API Token	Can use	-
Device Token	-	Can use

Data-format and timestamps

All API requests and responses use the JSON payloads only.
HTTP and MQTT device connector use the URL Encodeded payloads.
All timestamps are relative to UTC.Timestamps format is ISO8601:2004 standard.

NOTE

when stream retrieve,time range specified local timezone.(e.g. 'YYYY-MM-DD hh:mm')

Sample

e.g. Stream response(TZ="Asia/Tokyo")

{"_id":"54d3fc256807f4a616acbb33","value":11.1,"value2":47.9,"value3":null,"value4":null,"at":"2015-02-06T08:26:29+0900"}

e.g. Device list response(TZ="Asia/Tokyo")

{
  "device_id": "1085266243",
  "description": "sensirion sht-25",
  "enable": "true",
  "mapped_ch": 0,
  "device_type": "Xbee Pro2",
  "location": "Niigata,Japan",
  "manufacturer": "Sensincs,llc",
  "activate_at": "2015-01-13T16:58:00+09:00"
}

API rate limit

API usage is rate limited by per-second API request numbers.
The device connector rate limit by per-minutes request numbers.

Current rate limit settings as follows:

REST API
3 requests/sec.
Device Connector(HTTP ONLY)
1 connection/sec.

Servwatch Portal

API Reference (V2.0.0)