States & Subscriptions Storage (sts)

Table of Contents

Description
Limitations
Parameters
Configuration example
See also

Description

Store states and subscriptions to state changes of users of the system and SIP users.
Notifies subscribers when the integral states of accounts change. Each entry is recorded for a period of time and renewed periodically.

Divided into microservices by domain. Data is automatically synchronized between sites serving the domain.
Reserved in Active-Passive mode. Scaled by domain tree partitioning.

Table 1. System Characteristics

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

Limitations

State change events generated by the role for message brokers duplicate data across all sites where the domain is served. At the moment when sites are inaccessible to each other, the domain data in different sites' repositories may differ. This also leads to duplicates in the database, where events are stacked by recipients of messages from different sites, provided they have the same connection settings.
Sending state change events to the subscriber is done by the instance of the site that accepted and processed the subscription.

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: `"sts"`.
`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. Responsibilities between groups are shared across domain sets. Together, all groups maintain a complete domain set. All roles in the same group must have the same responsibility. 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.
`include_domains`	`array<str>`	empty	A list of domain names served by this group. Any domain of any level can be specified. Specifying a domain causes its subdomain tree to be served on this group and not on other role groups, excluding only those branches mentioned in other groups. Collectively, all role groups on a site serve a complete domain tree.
`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": "statestore1",
  "roletype": "sts",
  "iface": "eth0",

  "group": 11070,
  "order": 2,

  "include_domains": [
    "dev.rootdomain.ru"
  ]
}

States & Subscriptions Storage (sts)

Description

Limitations

Parameters

Configuration example

See also