`grpc.max_connection_age_grace` requires…

Error message

`grpc.max_connection_age_grace` requires `grpc.max_connection_age` to be set

What it means

The gRPC server config validation requires that `max_connection_age_grace` is only set together with `max_connection_age`: a grace period only makes sense as an extension of a connection's max age. Setting grace without age leaves the setting meaningless, so `GrpcConfig::validate` fails with this message.

Solutions

Add `grpc.max_connection_age` alongside `max_connection_age_grace`
Remove `grpc.max_connection_age_grace` if you don't want connection aging at all
Review the gRPC config section so both values are configured together

Example fix

// before
grpc:
  max_connection_age_grace: 30s
// after
grpc:
  max_connection_age: 60s
  max_connection_age_grace: 30s

Defensive patterns

Strategy: validation

Validate before calling

fn validate_grpc_age_pair(cfg: &GrpcConfig) -> anyhow::Result<()> {
    if cfg.max_connection_age_grace.is_some() && cfg.max_connection_age.is_none() {
        anyhow::bail!("grpc.max_connection_age_grace requires grpc.max_connection_age");
    }
    Ok(())
}

Try / catch

if let Err(e) = node_config.validate() {
    if e.to_string().contains("max_connection_age_grace") {
        eprintln!("Set both grpc.max_connection_age and max_connection_age_grace, or drop the grace value.");
    }
}

Prevention

Always configure connection age and grace as a pair
Comment out both lines together when disabling connection recycling
Diff your gRPC config against the reference example before deploying

When it happens

Trigger: Setting `grpc.max_connection_age_grace` in the node config while leaving `grpc.max_connection_age` unset, then loading/validating the node config.

Common situations: Tuning gRPC connection recycling and only partially copying example settings; a config template where the age line was commented out but the grace line remained.

Understand the failure class

Background: "is required", "must be set", "missing required field": configuration validation errors across open-source libraries — this error's family across 36 libraries.

Related errors

AI-assisted analysis of quickwit-oss/quickwit@a39730c5cd (2026-09-08). Data as JSON: /api/errors/16e7f9b437c317a1. Report an issue: GitHub.

Appendix: source

Thrown at quickwit/quickwit-config/src/node_config/mod.rs:138

    #[serde(default = "default_keep_alive_timeout")]
    pub timeout: HumanDuration,
}

impl GrpcConfig {
    fn default_max_message_size() -> ByteSize {
        ByteSize::mib(20)
    }

    pub fn validate(&self) -> anyhow::Result<()> {
        ensure!(
            self.max_message_size >= ByteSize::mb(1),
            "max gRPC message size (`grpc.max_message_size`) must be at least 1MB, got `{}`",
            self.max_message_size
        );
        if let Some(tls_config) = &self.tls_config {
            tls_config.validate()?;
        }
        ensure!(
            !(self.max_connection_age_grace.is_some() && self.max_connection_age.is_none()),
            "`grpc.max_connection_age_grace` requires `grpc.max_connection_age` to be set"
        );
        Ok(())
    }
}

impl Default for GrpcConfig {
    fn default() -> Self {
        Self {
            max_message_size: Self::default_max_message_size(),
            tls_config: None,
            keep_alive: None,
            max_connection_age: None,
            max_connection_age_grace: None,
        }
    }
}

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