From dc5fab93a887e5d99b3711e1886184777cdb3002 Mon Sep 17 00:00:00 2001
From: June <kimjune01@gmail.com>
Date: Mon, 11 May 2026 01:34:51 -0700
Subject: [PATCH] fix: remove unparsed [heartbeat] sections from node example
 configs (#8092)

Fixes #8087

FrontendOptions, DatanodeOptions, and FlownodeOptions do not define
a heartbeat field, so the [heartbeat] sections in their example TOML
files were never parsed.

Heartbeat intervals are actually negotiated from metasrv during the
heartbeat handshake:
- Datanode/Flownode: interval = metasrv.heartbeat_interval
- Frontend: interval = metasrv.heartbeat_interval * 6

This mislead operators into thinking they could tune heartbeat timing
locally. Remove the sections to eliminate confusion.

Metasrv's heartbeat_interval remains documented and functional.
---
 config/datanode.example.toml | 8 --------
 config/flownode.example.toml | 8 --------
 config/frontend.example.toml | 8 --------
 config/metasrv.example.toml  | 2 +-
 4 files changed, 1 insertion(+), 25 deletions(-)

diff --git a/config/datanode.example.toml b/config/datanode.example.toml
index 6effec4c87..fbe205c17a 100644
--- a/config/datanode.example.toml
+++ b/config/datanode.example.toml
@@ -80,14 +80,6 @@ watch = false
 ## The number of threads to execute the runtime for global write operations.
 #+ compact_rt_size = 4
 
-## The heartbeat options.
-[heartbeat]
-## Interval for sending heartbeat messages to the metasrv.
-interval = "3s"
-
-## Interval for retrying to send heartbeat messages to the metasrv.
-retry_interval = "3s"
-
 ## The metasrv client options.
 [meta_client]
 ## The addresses of the metasrv.
diff --git a/config/flownode.example.toml b/config/flownode.example.toml
index 8a819d562e..2c053e6e8c 100644
--- a/config/flownode.example.toml
+++ b/config/flownode.example.toml
@@ -97,14 +97,6 @@ metadata_cache_ttl = "10m"
 # TTI of the metadata cache.
 metadata_cache_tti = "5m"
 
-## The heartbeat options.
-[heartbeat]
-## Interval for sending heartbeat messages to the metasrv.
-interval = "3s"
-
-## Interval for retrying to send heartbeat messages to the metasrv.
-retry_interval = "3s"
-
 ## The logging options.
 [logging]
 ## The directory to store the log files. If set to empty, logs will not be written to files.
diff --git a/config/frontend.example.toml b/config/frontend.example.toml
index dfa0990cca..60115e93bb 100644
--- a/config/frontend.example.toml
+++ b/config/frontend.example.toml
@@ -28,14 +28,6 @@ default_column_prefix = "greptime"
 ## The number of threads to execute the runtime for global write operations.
 #+ compact_rt_size = 4
 
-## The heartbeat options.
-[heartbeat]
-## Interval for sending heartbeat messages to the metasrv.
-interval = "18s"
-
-## Interval for retrying to send heartbeat messages to the metasrv.
-retry_interval = "3s"
-
 ## The HTTP server options.
 [http]
 ## The address to bind the HTTP server.
diff --git a/config/metasrv.example.toml b/config/metasrv.example.toml
index 63235e56f1..8e27e5be26 100644
--- a/config/metasrv.example.toml
+++ b/config/metasrv.example.toml
@@ -79,7 +79,7 @@ node_max_idle_time = "24hours"
 ## The frontend heartbeat interval is 6 times of the base heartbeat interval.
 ## The flownode/datanode heartbeat interval is 1 times of the base heartbeat interval.
 ## e.g., If the base heartbeat interval is 3s, the frontend heartbeat interval is 18s, the flownode/datanode heartbeat interval is 3s.
-## If you change this value, you need to change the heartbeat interval of the flownode/frontend/datanode accordingly.
+## Heartbeat intervals are negotiated from metasrv during handshake; local node configs do not override this.
 #+ heartbeat_interval = "3s"
 
 ## Whether to enable greptimedb telemetry. Enabled by default.