View Source AntikytheraCore.Alert.Handler behaviour (antikythera v0.5.1)

Behaviour module for alert handlers.

Implementations must be prefixed with AntikytheraCore.Alert.Handler, e.g. AntikytheraCore.Alert.Handler.Email. This module also implements :gen_event behaviour and installed as handlers for AntikytheraCore.Alert.Manager processes. Each installed handlers will call callbacks of their corresponding implementation modules (references to those modules are held in handler states).

A simple buffering/throttling mechanism is built in.

  • Messages received by handlers will be sent out in "fast-then-delayed" pattern:
    • Occasional messages will be flushed from the buffer and sent out in fast_interval.
    • Messages arriving too frequently will be buffered for delayed_interval until they are sent out.
  • By default, fast_interval is 60 seconds and delayed_interval is 1800 seconds.
    • They can be customized via core/gear configs. Specify fast_interval or delayed_interval for the handler.

Customization and installation of handlers

Through validate_config/1 callback, handler_config will be validated whether it includes sufficient information required for the implementation. If the validation passed, a handler, with a reference to the implementation module, will be installed for that OTP application. If the validation failed, the handler will not be installed, and will be uninstalled if it is installed already.

This means, customization and installation are purely done via core/gear config.

Summary

Callbacks

send_alerts(messages, handler_config, otp_app_name)

Send alert(s) for messages in the buffer, using handler_config. Summarize messages if needed. Must return messages which could not be sent for whatever reason for retry. Oldest message comes first in messages, same goes for returned messages.

validate_config(handler_config)

Validate handler_config whether it includes sufficient configurations for the handler. Return true when it is valid.

Callbacks

Link to this callback

send_alerts(messages, handler_config, otp_app_name)

View Source 
@callback send_alerts(
  messages :: [AntikytheraCore.Alert.Message.t()],
  handler_config :: AntikytheraCore.Alert.HandlerConfig.t(),
  otp_app_name :: :antikythera | Antikythera.GearName.t()
) :: [AntikytheraCore.Alert.Message.t()]

Send alert(s) for messages in the buffer, using handler_config. Summarize messages if needed. Must return messages which could not be sent for whatever reason for retry. Oldest message comes first in messages, same goes for returned messages.

Note: If the handler is trying to perform alerts which can take some time to finish (e.g. send email), consider dispatching them to a temporary process. In that case though, results of alerts cannot be received ([] should always be returned).

Link to this callback

validate_config(handler_config)

View Source 
@callback validate_config(handler_config :: AntikytheraCore.Alert.HandlerConfig.t()) ::
  boolean()

Validate handler_config whether it includes sufficient configurations for the handler. Return true when it is valid.