feat: support reporting env vars in heartbeat messages to metasrv by v0y4g3r · Pull Request #8084 · GreptimeTeam/greptimedb

v0y4g3r · 2026-05-08T08:58:11Z

Summary

Add heartbeat_env_vars config option for datanode and frontend to specify environment variable keys whose values should be reported to metasrv in heartbeat messages
Metasrv extracts and stores these values in NodeInfo, enabling routing decisions like AZ-aware region placement
Implementation follows the existing GcStat extension pattern using the HeartbeatRequest.extensions map with key __env_vars

Changes

Config: Add heartbeat_env_vars: Vec<String> to DatanodeOptions, FrontendOptions, and StandaloneOptions
Serialization: Add EnvVars helper in common/meta/src/datanode.rs with from_config/into_extensions/from_extensions
Storage: Add env_vars: HashMap<String, String> field to NodeInfo in common/meta/src/cluster.rs with #[serde(default)] for backward compat
Datanode heartbeat: Read env vars once at startup, inject into extensions on each heartbeat
Frontend heartbeat: Same pattern, extensions are now populated for frontend heartbeats
Metasrv handlers: All three CollectXxxClusterInfoHandlers extract env vars from req.extensions and store in NodeInfo

Test plan

Unit tests for EnvVars round-trip serialization
Unit tests for NodeInfo backward compat (deserialize without env_vars field)
Integration test test_config_api updated for new config field
Manual test: configure heartbeat_env_vars, verify metasrv stores values in NodeInfo

Add `heartbeat_env_vars` config option for datanode and frontend. When configured, the specified environment variable values are read at startup and sent to metasrv in every heartbeat via the `extensions` map. Metasrv extracts and stores them in `NodeInfo` for use in routing decisions (e.g. AZ-aware region placement). - Add `EnvVars` helper in `common/meta/src/datanode.rs` following the existing `GcStat` extension pattern with `into_extensions`/`from_extensions` - Add `env_vars: HashMap<String, String>` field to `NodeInfo` in `common/meta/src/cluster.rs` with `#[serde(default)]` for backward compat - Add `heartbeat_env_vars: Vec<String>` config field to `DatanodeOptions`, `FrontendOptions`, and `StandaloneOptions` - Inject env vars into heartbeat `extensions` in both datanode and frontend heartbeat tasks (`datanode/src/heartbeat.rs`, `frontend/src/heartbeat.rs`) - Extract env vars from `req.extensions` in all three metasrv `CollectXxxClusterInfoHandler`s - Update `NodeInfo` construction sites in `meta-client`, `discovery/lease.rs`, and `standalone/information_extension.rs` - Update expected TOML output in `tests-integration/tests/http.rs` - Add unit tests for `EnvVars` round-trip and `NodeInfo` backward compat Signed-off-by: Lei, HUANG <leih@nvidia.com> Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

gemini-code-assist

Code Review

This pull request implements a mechanism for nodes to report specific environment variables to the meta service via heartbeat messages. It adds a heartbeat_env_vars configuration to Datanode, Frontend, and Standalone components, updates the NodeInfo structure to include an env_vars field, and modifies heartbeat handlers to propagate this data through request extensions. Feedback highlights an opportunity to refactor duplicated mapping logic in the meta-client and notes that environment variables are currently not populated in standalone mode, which affects the consistency of the information_schema.nodes table.

gemini-code-assist · 2026-05-08T09:01:49Z

                            cpu_usage_millicores: node_info.cpu_usage_millicores,
                            memory_usage_bytes: node_info.memory_usage_bytes,
                            hostname: node_info.hostname,
+                            env_vars: Default::default(),


The mapping logic from the Protobuf NodeInfo to the internal NodeInfo struct is duplicated multiple times in this file (e.g., lines 460-463, 476-480, 494-498, 510-514). This violates the general rule of refactoring duplicated logic into shared helper functions to improve maintainability. Consider creating a helper method to handle this conversion, which would also make it easier to propagate env_vars if they are added to the Protobuf definition in the future.

References

Refactor duplicated logic (like environment variable extraction) into shared helper functions to improve maintainability and reduce code duplication.

gemini-code-assist · 2026-05-08T09:01:49Z

                .unwrap_or_default()
                .to_string_lossy()
                .to_string(),
+            env_vars: Default::default(),


In standalone mode, the env_vars field is hardcoded to Default::default(). This means that environment variables configured via heartbeat_env_vars will not be visible in the information_schema.nodes table when running in standalone mode. To ensure consistency across deployment modes and provide a complete view of node metadata, this extension should be updated to populate env_vars from the process environment based on the configured keys.

Copilot

Pull request overview

Adds a configurable mechanism for datanode/frontend (and standalone via option propagation) to report selected environment variable values to metasrv via heartbeat extensions, and persists them into NodeInfo for later routing/placement decisions (e.g., AZ-aware logic).

Changes:

Introduces heartbeat_env_vars: Vec<String> in datanode/frontend/standalone options and wires it into env-based config loading.
Implements EnvVars (serialize into / deserialize from heartbeat extensions under __env_vars) and stores extracted values in common_meta::cluster::NodeInfo.
Updates heartbeat senders (datanode/frontend) and metasrv heartbeat handlers to populate/extract the env-var extension; expands tests for config loading and serialization/backward-compat.

Reviewed changes

Copilot reviewed 14 out of 14 changed files in this pull request and generated 3 comments.

Show a summary per file

File	Description
tests-integration/tests/http.rs	Updates `/config` expected output to include `heartbeat_env_vars = []`.
src/standalone/src/options.rs	Adds `heartbeat_env_vars` to standalone config and propagates into frontend/datanode options.
src/standalone/src/information_extension.rs	Updates standalone `NodeInfo` construction for the new `env_vars` field.
src/meta-srv/src/handler/collect_cluster_info_handler.rs	Extracts `__env_vars` from heartbeat extensions and stores into `NodeInfo`.
src/meta-srv/src/discovery/lease.rs	Updates metasrv discovery tests to populate `NodeInfo.env_vars`.
src/meta-client/src/client/util.rs	Updates meta-client test helpers for the new `NodeInfo.env_vars` field.
src/meta-client/src/client.rs	Ensures metasrv node info construction populates `env_vars` (default).
src/frontend/src/heartbeat.rs	Reads configured env vars once at startup and injects into heartbeat extensions.
src/frontend/src/frontend.rs	Adds `heartbeat_env_vars` to frontend options and env list parsing keys.
src/datanode/src/heartbeat.rs	Reads configured env vars once at startup and injects into heartbeat extensions (alongside existing GC stat extension).
src/datanode/src/config.rs	Adds `heartbeat_env_vars` to datanode options and env list parsing keys.
src/common/meta/src/datanode.rs	Adds `EnvVars` helper + unit tests for extension round-trip behavior.
src/common/meta/src/cluster.rs	Adds `NodeInfo.env_vars` with serde default + tests for backward compatibility and round-trip.
src/cmd/tests/load_config_test.rs	Adds env-based config loading test for `heartbeat_env_vars` across components.

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    pub memory: MemoryOptions,
    /// The event recorder options.
    pub event_recorder: EventRecorderOptions,
+    /// Environment variable keys to read and report in heartbeat messages.


    pub slow_query: SlowQueryOptions,
    pub query: QueryOptions,
    pub memory: MemoryOptions,
+    /// Environment variable keys to read and report in heartbeat messages.


+    let env_vars = EnvVars::from_extensions(&request.extensions)
+        .inspect_err(|e| {
+            warn!(e;
+                "Failed to deserialize __env_vars from heartbeat extensions, peer: {}", peer


v0y4g3r added 6 commits May 5, 2026 23:14

refactor: address heartbeat env review feedback

36c7281

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

chore: log error on deserialization failure

b9e3669

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

refactor: send heartbeat env vars once

d8e87e7

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

fix: resend heartbeat env vars after reconnect

229f920

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

revert: keep env vars in every heartbeat

a87502e

Signed-off-by: Lei, HUANG <mrsatangel@gmail.com>

Copilot AI review requested due to automatic review settings May 8, 2026 08:58

v0y4g3r requested review from a team, MichaelScofield and WenyXu as code owners May 8, 2026 08:58

github-actions Bot added docs-not-required This change does not impact docs. size/S labels May 8, 2026

gemini-code-assist Bot reviewed May 8, 2026

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feat: support reporting env vars in heartbeat messages to metasrv#8084

feat: support reporting env vars in heartbeat messages to metasrv#8084
v0y4g3r wants to merge 6 commits intoGreptimeTeam:mainfrom
v0y4g3r:feat/env-in-heartbeat

v0y4g3r commented May 8, 2026

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v0y4g3r commented May 8, 2026

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