ACP-267: Uptime Requirement Increase

ACP	267
Title	Increase Validator Uptime Requirement from 80% to 90%
Author(s)	Martin Eckardt (@martineckardt)
Status	Proposed Discussion
Track	Best Practices

Abstract

This proposal increases the minimum uptime requirement for Avalanche Primary Network validators from 80% to 90%. Validators must maintain at least 90% uptime during their staking period to receive their validation rewards. This change aims to enhance overall network health, reliability, and performance by ensuring validators meet a higher standard of availability.

Motivation

Current State

The Avalanche Primary Network currently requires validators to maintain a minimum of 80% uptime during their staking period to be eligible for staking rewards. While this threshold has served the network adequately, there are compelling reasons to raise the bar.

Need for Enhanced Network Reliability

Higher validator uptime is essential for achieving further performance gains across the Avalanche Primary Network. Even a small number of validators operating at 80% uptime can cause substantial network degradation, including increased latency in API endpoints and delayed block finalization.

When the Snowman consensus protocol queries validators about a block, encountering too many non-responsive nodes among the sampled set causes the query to fail. This forces the protocol to issue additional queries, delaying block agreement and reducing overall network throughput. As a result, sustained validator availability is critical to ensure the network consistently processes transactions at optimal speed.

Specification

Technical Changes

Update the validator uptime requirement from 80% to 90% by changing the following in MainnetParams (defined in genesis/genesis_mainnet.go):

StakingConfig: StakingConfig{
	UptimeRequirement: .9, // 90%
}

The same change would be applied to genesis/genesis_fuji.go and genesis/genesis_local.go for consistency across all networks.

Implementation Details

The proposed change only raises the validator uptime requirement to 90%, with the uptime calculation method remaining unchanged. Validators are measured by their observed responsiveness during the staking period. Validators and their delegators will only receive rewards if the validator achieves at least 90% uptime; otherwise, they receive no rewards, maintaining the current all-or-nothing reward model with no partial payouts.

Effective Date

The 90% uptime requirement only applies to validations that meet both of the following conditions:

The validation started on or after April 1, 2026.
The validation has not ended before the activation time of the AvalancheGo release implementing this ACP.

Validations that started before April 1, 2026, or that ended before the activation of this change, continue to be evaluated against the existing 80% uptime threshold.

Backwards Compatibility

Each node continuously tracks its perceived uptime of its peers throughout the peer's validator staking period. At the end of the peer's validator staking period, each node sets its preference of whether or not to reward the peer based on its perceived uptime.

The effective date ensures that validators who began their staking period without knowledge of the increased requirement are not retroactively penalized. This ACP was announced on February 10, 2026, and notifications were added in relevant places including the Core staking UI, block explorers, and validator uptime statistics dashboards. The April 1, 2026 effective date provides sufficient lead time for validators to adjust their infrastructure.