# Which Problems Are Solved
The current handling of notification follows the same pattern as all
other projections:
Created events are handled sequentially (based on "position") by a
handler. During the process, a lot of information is aggregated (user,
texts, templates, ...).
This leads to back pressure on the projection since the handling of
events might take longer than the time before a new event (to be
handled) is created.
# How the Problems Are Solved
- The current user notification handler creates separate notification
events based on the user / session events.
- These events contain all the present and required information
including the userID.
- These notification events get processed by notification workers, which
gather the necessary information (recipient address, texts, templates)
to send out these notifications.
- If a notification fails, a retry event is created based on the current
notification request including the current state of the user (this
prevents race conditions, where a user is changed in the meantime and
the notification already gets the new state).
- The retry event will be handled after a backoff delay. This delay
increases with every attempt.
- If the configured amount of attempts is reached or the message expired
(based on config), a cancel event is created, letting the workers know,
the notification must no longer be handled.
- In case of successful send, a sent event is created for the
notification aggregate and the existing "sent" events for the user /
session object is stored.
- The following is added to the defaults.yaml to allow configuration of
the notification workers:
```yaml
Notifications:
# The amount of workers processing the notification request events.
# If set to 0, no notification request events will be handled. This can be useful when running in
# multi binary / pod setup and allowing only certain executables to process the events.
Workers: 1 # ZITADEL_NOTIFIACATIONS_WORKERS
# The amount of events a single worker will process in a run.
BulkLimit: 10 # ZITADEL_NOTIFIACATIONS_BULKLIMIT
# Time interval between scheduled notifications for request events
RequeueEvery: 2s # ZITADEL_NOTIFIACATIONS_REQUEUEEVERY
# The amount of workers processing the notification retry events.
# If set to 0, no notification retry events will be handled. This can be useful when running in
# multi binary / pod setup and allowing only certain executables to process the events.
RetryWorkers: 1 # ZITADEL_NOTIFIACATIONS_RETRYWORKERS
# Time interval between scheduled notifications for retry events
RetryRequeueEvery: 2s # ZITADEL_NOTIFIACATIONS_RETRYREQUEUEEVERY
# Only instances are projected, for which at least a projection-relevant event exists within the timeframe
# from HandleActiveInstances duration in the past until the projection's current time
# If set to 0 (default), every instance is always considered active
HandleActiveInstances: 0s # ZITADEL_NOTIFIACATIONS_HANDLEACTIVEINSTANCES
# The maximum duration a transaction remains open
# before it spots left folding additional events
# and updates the table.
TransactionDuration: 1m # ZITADEL_NOTIFIACATIONS_TRANSACTIONDURATION
# Automatically cancel the notification after the amount of failed attempts
MaxAttempts: 3 # ZITADEL_NOTIFIACATIONS_MAXATTEMPTS
# Automatically cancel the notification if it cannot be handled within a specific time
MaxTtl: 5m # ZITADEL_NOTIFIACATIONS_MAXTTL
# Failed attempts are retried after a confogired delay (with exponential backoff).
# Set a minimum and maximum delay and a factor for the backoff
MinRetryDelay: 1s # ZITADEL_NOTIFIACATIONS_MINRETRYDELAY
MaxRetryDelay: 20s # ZITADEL_NOTIFIACATIONS_MAXRETRYDELAY
# Any factor below 1 will be set to 1
RetryDelayFactor: 1.5 # ZITADEL_NOTIFIACATIONS_RETRYDELAYFACTOR
```
# Additional Changes
None
# Additional Context
- closes#8931
# Which Problems Are Solved
Twilio supports a robust, multi-channel verification service that
notably supports multi-region SMS sender numbers required for our use
case. Currently, Zitadel does much of the work of the Twilio Verify (eg.
localization, code generation, messaging) but doesn't support the pool
of sender numbers that Twilio Verify does.
# How the Problems Are Solved
To support this API, we need to be able to store the Twilio Service ID
and send that in a verification request where appropriate: phone number
verification and SMS 2FA code paths.
This PR does the following:
- Adds the ability to use Twilio Verify of standard messaging through
Twilio
- Adds support for international numbers and more reliable verification
messages sent from multiple numbers
- Adds a new Twilio configuration option to support Twilio Verify in the
admin console
- Sends verification SMS messages through Twilio Verify
- Implements Twilio Verification Checks for codes generated through the
same
# Additional Changes
# Additional Context
- base was implemented by @zhirschtritt in
https://github.com/zitadel/zitadel/pull/8268❤️
- closes https://github.com/zitadel/zitadel/issues/8581
---------
Co-authored-by: Zachary Hirschtritt <zachary.hirschtritt@klaviyo.com>
Co-authored-by: Joey Biscoglia <joey.biscoglia@klaviyo.com>
