# Manage Your Deprecations

Libraries or applications may have specific features who are strongly related to Eventlet, like the `heartbeat_in_pthread` feature in the Opentack oslo.messaging deliverable.

Migrating off of Eventlet would make these features obsolete. As this kind of feature expose configuration endpoints people would have to deprecate them to allow your users to update their config files accordingly. However, the deprecation process would take several months or even numerous versions before hoping to see these features removed. Hence blocking the migration.

The proposed solution is to mock these features with empty entrypoints who will only raise deprecation warnings to inform your users that they have to update their config files. After 1 or 2 new versions these empty mocks could be safely removed without impacting anybody.

In other words, these feature will remain in the code, but they will do nothing. They will be empty feature allowing us to migrate properly.

Example with the `heartbeat_in_pthread` feature, by using Asyncio we wouldn’t have to run heartbeats in a separated threads. This feature, the RabbitMQ heartbeat, would be run in a coroutine. A coroutine who is ran in the main native thread. The config option will remain available but it will only show a deprecation warning like the following one:

    __main__:1: DeprecationWarning: Using heartbeat_in_pthread is
    deprecated and will be removed in {SERIES}. Enabling that feature
    have no functional effects due to recent changes applied in the
    networking model used by oslo.messaging. Please plan an update of your
    configuration.