How to Freeze Protocols

After each protocol activation, old protocols are kept in the codebase. However large parts of the code developed for the previous protocol can now be removed to avoid accumulating dead code in the repository. All daemons, tests associated to old protocols, and RW (read-write) commands available to the client can be removed.

In this document, “protocol” refers to the protocol that we want to freeze, N, and “current protocol” refers to its successor, N+1. For instance, if “protocol” refers to 008, “current protocol” refers to 009.

The various pieces of code to be removed are within directory src/proto_<N>_<Hash>/, unless indicated otherwise.

Update Manifest

In manifest/, look for let alpha = active Name.alpha. In one of the lines above it is the declaration of the protocol you are freezing. Replace active by frozen for this protocol. Run the manifest with make -C manifest.

Remove Accuser, Baker

These daemons are no longer needed. Thus, the code in bin_{accuser,baker}/ can be safely removed and script-inputs/active_testing_protocol_versions should be modified accordingly.

Remove Protocol Tests

All tests developed for the protocol can be removed.

These are defined in

  • lib_client/test

  • lib_protocol/test

  • tests_python/tests_XXX

Remove lib_delegate

This code is no longer needed and can be safely removed.

Remove Protocol Tests From Tezt

The code of Tezt must be updated manually removing the protocol from the type Protocol.t and adapting the tests accordingly.

Remove Testnet From bin_node

Mentions of the protocol’s testnets should be removed from the node executable. In particular the file src/lib_node_config/ should be amended.

The protocol plugin registration module should be removed from src/bin_node/dune and opam/octez-node.opam.

Remove Protocol From Python Tests of Current Protocol

Tests and from the current protocol should be removed. Any mention of the protocol in tests_python/tests_XXX/ should also be removed.

These changes remove the migration testing code of the current protocol that is no longer necessary to test.

Remove RW Commands From lib_client_commands

The client commands at proto_XXX/lib_client_commands/ define both read-only and read-write commands, where reads and writes refer to accesses to and modifications of the state of the chain. The RW commands can now be safely removed as they are no longer needed.

Remove Mempool Protocol Plugins

The Mempool protocol plugin located in proto_XXX/lib_plugin/ can be removed. This implies removing the plugin code, and remove the registration of the plugin in the file proto_XXX/lib_plugin/

Other plugins should be evaluated case-by-case. At the moment of writing, the Mempool plugin is the only one that can be safely removed.

Remove Old Docker-Compose Files

The docker-compose file with the corresponding protocol name can be removed from the scripts/docker directory.

Add an Entry in CHANGES.rst

Add an entry in CHANGES.rst to summarize all changes for the user.

In particular it should mention:

  • that the protocol’s daemons were removed;

  • that the corresponding --network alias was removed.