Broker of messages (broker)

Table of Contents

Description
Limitations
Parameters
Configuration example
See also

Description

System Message Broker.
Ensures data is received and retained without disrupting enrollment.

Guarantees delivery of received messages to consumers. When a message is taken by a consumer, the message is automatically deleted (unlike the well-known brokers that save messages for some time). +

Temporarily and limitedly stores event data from various processes generated at the current site.
Used as a job queue for post-processing processes (cdr aggregator, mixer, packager, stenographer, etc.).

Reserved in mode Active-Passive.
Scalable by partitioning into groups by domain. Potentially, in case of performance shortage it can be divided into groups by queue names. Principle: one queue - one group.

Table 1. System Characteristics

Code	`broker`
Mode of operation	`Service, storage`
Backup mode	`Active-Passive`
Types of sites	`Any`
Layer	`Business logic`
Placement	`Internal`
Saving and restoring state on reboot	`Yes`
appendix	`era_broker`
Own storage	`ODB Mnesia`

Limitations

The maximum number of items in one queue is 2 million. When the limit is reached, the oldest messages are automatically deleted.
The maximum message broker throughput for receiving and issuing messages is about 40 thousand messages per second.

Parameters

Description of columns in the table

Table 2. Parameters
Name	Type	Default	Description
`name`	`str`	required	Name. May consist of Latin letters and numbers, must begin with a letter.
`roletype`	`str`	required	Role Type. Possible values: `"broker"`.
`iface`	`str`	required	The alias of the server network interface on which the roles will interact internally with each other.
`ext`	`json`	empty	Additional role options. Contains a json object or list.
`enabled`	`bool`	empty	Role activity flag. When set to false, the role does not participate in validation and is not started.
`group`	`int`	required	Group Number. As part of horizontal scaling, a role can be divided into multiple groups on a site, with only one instance active in each group and the rest reserved. Responsibility between groups is divided by queue type (or event class). Integer from `1` to `9999999`.
`order`	`int`	required	The order of a role instance within a group. Defines in what order the flow in the mode will take place Active-Passive.
`mnesia_storage_mode`	`str`	`disc` "Mode of operation of object storage.	Possible options:
`* disc - full mode`	`in RAM with saving to disk on all instances of the group.`	ram - only in RAM (with support for distributed	transactional). If all instances of the group are rebooted/shut down simultaneously

Configuration example

The configuration is managed in an application available to master domain administrators. The application hides the full content of the configuration, but it is nevertheless accessible via the API.

The configuration contains a section to describe all instances of all roles. Parameters are defined for each specific role instance.

Example node

{
  "name": "broker1",
  "roletype": "broker",
  "iface": "eth0",

  "group": 11400,
  "order": 1
}

Broker of messages (broker)

Description

Limitations

Parameters

Configuration example

See also