1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
|
==========================
Messaging service overview
==========================
The Message service is multi-tenant, fast, reliable, and scalable. It allows
developers to share data between distributed application components performing
different tasks, without losing messages or requiring each component to be
always available.
The service features a RESTful API and a Websocket API, which developers can
use to send messages between various components of their SaaS and mobile
applications, by using a variety of communication patterns.
Key features
~~~~~~~~~~~~
The Messaging service provides the following key features:
* Choice between two communication transports. Both with Identity service
support:
* Firewall-friendly, **HTTP-based RESTful API**. Many of today's developers
prefer a more web-friendly HTTP API. They value the simplicity and
transparency of the protocol, its firewall-friendly nature, and its huge
ecosystem of tools, load balancers and proxies. In addition, cloud
operators appreciate the scalability aspects of the REST architectural
style.
* **Websocket-based API** for persistent connections. Websocket protocol
provides communication over persistent connections. Unlike HTTP, where
new connections are opened for each request/response pair, Websocket can
transfer multiple requests/responses over single TCP connection. It saves
much network traffic and minimizes delays.
* Multi-tenant queues based on Identity service IDs.
* Support for several common patterns including event broadcasting, task
distribution, and point-to-point messaging.
* Component-based architecture with support for custom back ends and message
filters.
* Efficient reference implementation with an eye toward low latency and high
throughput (dependent on back end).
* Highly-available and horizontally scalable.
* Support for subscriptions to queues. Several notification types are
available:
* Email notifications
* Webhook notifications
* Websocket notifications
Layers of the Messaging service
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The Messaging service has following layers:
* The transport layer (Messaging application) which can provide these APIs:
* HTTP RESTful API (via ``wsgi`` driver).
* Websocket API (via ``websocket`` driver).
* The storage layer which keeps all the data and metadata about queues and
messages. It has two sub-layers:
* The management store database (Catalog). Can be ``MongoDB`` database (or
``MongoDB`` replica-set) or SQL database.
* The message store databases (Pools). Can be ``MongoDB`` database (or
``MongoDB`` replica-set) or ``Redis`` database.
|
