feat: Support export metric in remote write format

config/standalone.example.toml

@@ -177,3 +177,15 @@ parallel_scan_channel_size = 32
 # otlp_endpoint = "localhost:4317"
 # The percentage of tracing will be sampled and exported. Valid range `[0, 1]`, 1 means all traces are sampled, 0 means all traces are not sampled, the default value is 1. ratio > 1 are treated as 1. Fractions < 0 are treated as 0
 # tracing_sample_ratio = 1.0
+
+# standalone/frontend/datanode/metasrv export the metrics generated by itself
+# send metrics to Prometheus remote-write compatible receiver (e.g. `greptimedb`)
+# [remote_write]
+# whether enable export remote_write, default is false
+# enable = false
+# The url of remote write endpoint.
+# Taking greptimedb as an example, for `standalone` deployed under the default configuration.
+# The user can create a database called `system` in the db and export the metric to `http://127.0.0.1:4000/v1/prometheus/write?db=system`
+# endpoint = "http://127.0.0.1:4000/v1/prometheus/write?db=system"
+# The interval of export metric, 
+# write_interval = "30s"

src/cmd/src/frontend.rs

@@ -249,6 +249,10 @@ impl StartCommand {
         .await
         .context(StartFrontendSnafu)?;
 
+        instance
+            .build_remote_write_metric_task(&opts.remote_write)
+            .context(StartFrontendSnafu)?;
+
         instance
             .build_servers(opts)
             .await

src/cmd/src/standalone.rs

@@ -45,6 +45,7 @@ use frontend::service_config::{
 use mito2::config::MitoConfig;
 use serde::{Deserialize, Serialize};
 use servers::http::HttpOptions;
+use servers::remote_writer::RemoteWriteOptions;
 use servers::tls::{TlsMode, TlsOption};
 use servers::Mode;
 use snafu::ResultExt;
@@ -112,6 +113,7 @@ pub struct StandaloneOptions {
     pub user_provider: Option<String>,
     /// Options for different store engines.
     pub region_engine: Vec<RegionEngineConfig>,
+    pub remote_write: RemoteWriteOptions,
 }
 
 impl Default for StandaloneOptions {
@@ -131,6 +133,7 @@ impl Default for StandaloneOptions {
             metadata_store: KvBackendConfig::default(),
             procedure: ProcedureConfig::default(),
             logging: LoggingOptions::default(),
+            remote_write: RemoteWriteOptions::default(),
             user_provider: None,
             region_engine: vec![
                 RegionEngineConfig::Mito(MitoConfig::default()),
@@ -154,6 +157,8 @@ impl StandaloneOptions {
             meta_client: None,
             logging: self.logging,
             user_provider: self.user_provider,
+            // Handle the remote write metric task run by standalone to frontend for execution
+            remote_write: self.remote_write,
             ..Default::default()
         }
     }
@@ -399,6 +404,10 @@ impl StartCommand {
             .await
             .context(StartFrontendSnafu)?;
 
+        frontend
+            .build_remote_write_metric_task(&opts.frontend.remote_write)
+            .context(StartFrontendSnafu)?;
+
         frontend
             .build_servers(opts)
             .await

src/common/telemetry/Cargo.toml

@@ -12,6 +12,7 @@ deadlock_detection = ["parking_lot/deadlock_detection"]
 backtrace = "0.3"
 common-error.workspace = true
 console-subscriber = { version = "0.1", optional = true }
+greptime-proto.workspace = true
 lazy_static.workspace = true
 once_cell.workspace = true
 opentelemetry = { version = "0.21.0", default-features = false, features = [