Best Practices to Run a Signer

Intended audience: solo Stackers or Stacking pool operators.

The following best practices suggest how to create a resilient setup for running your Signer.

tl;dr: avoid single point of failures, introduce redundancy, monitor things.

Monitor your Signer and collect logs

• See here on how to set up monitoring.

• Retain at least 1 week of logs for both the Signer and the Stacks node.

Downstream components

• Run a dedicated Bitcoin node and Stacks node per Signer.

  • Ensure the nodes are provisioned with the minimum hardware requirements described here.

  • Nodes should be exclusively dedicated to serve the Signer. Avoid re-using them to serve other clients as that may negatively affect performance (no mock-signing, no Stacks API nodes).

• If running dedicated nodes is not possible, then ensure that the Bitcoin / Stacks nodes do not become single points of failure for multiple signers depending on them.

  • Introduce redundancy, load balancing, rely on a robust Bitcoin RPC provider, etc.

Split voting power across multiple Signers

• Distribute your voting power across multiple, distinct Signer public keys to mitigate the risk of loss or downtime from a single compromised key.

• Each Signer should also limit voting power to a maximum amount and invite Stackers to use a different Signer when the limit is reached.

Monitor new software releases

• Stay up-to-date with new releases, patches, and security advisories (e.g., GitHub, mailing lists, Discord).

• Apply updates as quickly as possible, especially those addressing a security vulnerability.

Upgrade procedures

1

Test one instance first

Upgrade one Signer instance at a time. Test the update on a single instance and verify functionality before proceeding to others.

2

Roll out gradually

If the test is successful, proceed to upgrade the remaining instances one-by-one.

3

Minimize downtime

While a Signer is offline for upgrades, it won't sign any blocks. Ensure that the downtime is as short as possible.

Diversified hosting

• Use different provider / configuration where feasible (e.g., a self-hosted instance and one in the cloud, or in two different data center regions, etc.).

• Ensure each host has redundant power supply and network connectivity.

Fall-back deployments

• Deploy additional Stacks nodes and Bitcoin nodes to be used as fall-back.

  • Use the same configuration as your active instances.

  • For the Stacks node, comment out the event_observer section.

• Prepare a backup Signer (same configuration) to be quickly activated, but do not run it.

  • At all times, there should be exactly one Signer instance running for each Signer private key.

• These fall-back instances should be hosted on separate physical hosts (see diversified hosting) from the instances usually active in operations (serving each Signer).

To switch to the fall-back configuration quickly if an active instance fails, follow these steps:

1

Run the backup Signer

Start the prepared backup Signer instance.

2

Enable event observer

Enable the event_observer section of the Stacks node configuration.

3

Restart the node

Restart the Stacks node so it runs with the enabled event_observer.

Redundancy in operations

• Ensure that multiple, trusted users can manage and maintain signer instances.

• Where feasible, users should span different timezones.

Backup signer keys in cold-storage

• Keep an offline, secure backup of all Signer private keys (e.g., hardware security modules or encrypted storage devices).