# Chain Upgrade Guide to v0.44
This document provides guidelines for a chain upgrade from v0.42 to v0.44 and an example of the upgrade process using
You must upgrade to Stargate v0.42 before upgrading to v0.44. If you have not done so, please see Chain Upgrade Guide to v0.42. Please note, v0.43 was discontinued shortly after being released and all chains should upgrade directly to v0.44 from v0.42.
# Prerequisite Readings
Cosmos SDK v0.44 introduces a new way of handling chain upgrades that no longer requires exporting state to JSON, making the necesssary changes, and then creating a new chain with the modified JSON as the new genesis file.
Instead of starting a new chain, the upgrade binary will read the existing database and perform in-place store migrations. This new way of handling chain upgrades can be used alongside Cosmovisor to make the upgrade process seamless.
# In-Place Store Migrations
We recommend using In-Place Store Migrations to upgrade your chain from v0.42 to v0.44. The first step is to make sure all your modules follow the Module Upgrade Guide. The second step is to add an upgrade handler to
In this document, we'll provide an example of what the upgrade handler looks like for a chain upgrading module versions for the first time. It's critical to note that the initial consensus version of each module must be set to
1 rather than
0 or else the upgrade handler will re-initialize each module.
In addition to migrating existing modules, the upgrade handler also performs store upgrades for new modules. In the example below, we'll be adding store migrations for two new modules made available in v0.44:
# Using Cosmovisor
We recommend validators use Cosmovisor, which is a process manager for running application binaries. For security reasons, we recommend validators build their own upgrade binaries rather than enabling the auto-download option. Validators may still choose to use the auto-download option if the necessary security guarantees are in place (i.e. the URL provided in the upgrade proposal for the downloadable upgrade binary includes a proper checksum).
If validators would like to enable the auto-download option, and they are currently running an application using Cosmos SDK
v0.42, they will need to use Cosmovisor
v0.1 (opens new window). Later versions of Cosmovisor do not support Cosmos SDK
v0.42 or earlier if the auto-download option is enabled.
Validators can use the auto-restart option to prevent unnecessary downtime during the upgrade process. The auto-restart option will automatically restart the chain with the upgrade binary once the chain has halted at the proposed upgrade height. With the auto-restart option, validators can prepare the upgrade binary in advance and then relax at the time of the upgrade.
# Migrating app.toml
With the update to
v0.44, new server configuration options have been added to
app.toml. The updates include new configuration sections for Rosetta and gRPC Web as well as a new configuration option for State Sync. Check out the default
app.toml (opens new window) file in the latest version of
v0.44 for more information.
# Example: Simapp Upgrade
The following example will walk through the upgrade process using
simapp as our blockchain application. We will be upgrading
simapp from v0.42 to v0.44. We will be building the upgrade binary ourselves and enabling the auto-restart option.
In the following example, we start a new chain from
v0.42. The binary for this version will be the genesis binary. For validators using Cosmovisor for the first time on an existing chain, either the binary for the current version of the chain should be used as the genesis binary (i.e. the starting binary) or validators should update the
current symbolic link to point to the upgrade directory. For more information, see Cosmovisor.
# Initial Setup
From within the
cosmos-sdk repository, check out the latest
simd binary for the latest
v0.42.x release (the genesis binary):
~/.simapp (never do this in a production environment):
simd binary for testing:
Initialize the node and overwrite any previous genesis file (never do this in a production environment):
Set the minimum gas price to
For the purpose of this demonstration, change
genesis.json to a reduced time of 20 seconds (
Create a new key for the validator, then add a genesis account and transaction:
Now that our node is initialized and we are ready to start a new
simapp chain, let's set up
cosmovisor and the genesis binary.
# Cosmovisor Setup
If you are using go
v1.15 or earlier, you will need to change out of the
cosmos-sdk directory, run
go get instead of
go install, and then change back into the
Set the required environment variables:
Set the optional environment variable to trigger an automatic restart:
Create the folder for the genesis binary and copy the
cosmovisor is installed and the genesis binary has been added, let's add the upgrade handler to
simapp/app.go and prepare the upgrade binary.
# Chain Upgrade
Add the following to
NewSimApp and after
Add the following to
NewSimApp (to learn more about the upgrade handler, see the In-Place Store Migrations):
storetypes to imports:
simd binary for
v0.44.x (the upgrade binary):
Create the folder for the upgrade binary and copy the
Now that we have added the upgrade handler and prepared the upgrade binary, we are ready to start
cosmovisor and simulate the upgrade proposal process.
# Upgrade Proposal
Start the node using
Open a new terminal window and submit an upgrade proposal along with a deposit and a vote (these commands must be run within 20 seconds of each other):
Confirm the chain automatically upgrades at height 20.