add hadron-specific metrics (#12686)

compute_tools/src/hadron_metrics.rs

@@ -0,0 +1,60 @@
+use metrics::{
+    IntCounter, IntGaugeVec, core::Collector, proto::MetricFamily, register_int_counter,
+    register_int_gauge_vec,
+};
+use once_cell::sync::Lazy;
+
+// Counter keeping track of the number of PageStream request errors reported by Postgres.
+// An error is registered every time Postgres calls compute_ctl's /refresh_configuration API.
+// Postgres will invoke this API if it detected trouble with PageStream requests (get_page@lsn,
+// get_base_backup, etc.) it sends to any pageserver. An increase in this counter value typically
+// indicates Postgres downtime, as PageStream requests are critical for Postgres to function.
+pub static POSTGRES_PAGESTREAM_REQUEST_ERRORS: Lazy<IntCounter> = Lazy::new(|| {
+    register_int_counter!(
+        "pg_cctl_pagestream_request_errors_total",
+        "Number of PageStream request errors reported by the postgres process"
+    )
+    .expect("failed to define a metric")
+});
+
+// Counter keeping track of the number of compute configuration errors due to Postgres statement
+// timeouts. An error is registered every time `ComputeNode::reconfigure()` fails due to Postgres
+// error code 57014 (query cancelled). This statement timeout typically occurs when postgres is
+// stuck in a problematic retry loop when the PS is reject its connection requests (usually due
+// to PG pointing at the wrong PS). We should investigate the root cause when this counter value
+// increases by checking PG and PS logs.
+pub static COMPUTE_CONFIGURE_STATEMENT_TIMEOUT_ERRORS: Lazy<IntCounter> = Lazy::new(|| {
+    register_int_counter!(
+        "pg_cctl_configure_statement_timeout_errors_total",
+        "Number of compute configuration errors due to Postgres statement timeouts."
+    )
+    .expect("failed to define a metric")
+});
+
+pub static COMPUTE_ATTACHED: Lazy<IntGaugeVec> = Lazy::new(|| {
+    register_int_gauge_vec!(
+        "pg_cctl_attached",
+        "Compute node attached status (1 if attached)",
+        &[
+            "pg_compute_id",
+            "pg_instance_id",
+            "tenant_id",
+            "timeline_id"
+        ]
+    )
+    .expect("failed to define a metric")
+});
+
+pub fn collect() -> Vec<MetricFamily> {
+    let mut metrics = Vec::new();
+    metrics.extend(POSTGRES_PAGESTREAM_REQUEST_ERRORS.collect());
+    metrics.extend(COMPUTE_CONFIGURE_STATEMENT_TIMEOUT_ERRORS.collect());
+    metrics.extend(COMPUTE_ATTACHED.collect());
+    metrics
+}
+
+pub fn initialize_metrics() {
+    Lazy::force(&POSTGRES_PAGESTREAM_REQUEST_ERRORS);
+    Lazy::force(&COMPUTE_CONFIGURE_STATEMENT_TIMEOUT_ERRORS);
+    Lazy::force(&COMPUTE_ATTACHED);
+}

compute_tools/src/lib.rs

@@ -16,6 +16,7 @@ pub mod compute_prewarm;
 pub mod compute_promote;
 pub mod disk_quota;
 pub mod extension_server;
+pub mod hadron_metrics;
 pub mod installed_extensions;
 pub mod local_proxy;
 pub mod lsn_lease;