proxy: Report warm cold start if connection is from the local cache (#7104)

## Problem

* quotes in serialized string
* no status if connection is from local cache

## Summary of changes

* remove quotes
* report warm if connection if from local cache

proxy/src/console/provider/neon.rs

@@ -6,7 +6,9 @@ use super::{
     ApiCaches, ApiLocks, AuthInfo, AuthSecret, CachedAllowedIps, CachedNodeInfo, CachedRoleSecret,
     NodeInfo,
 };
-use crate::{auth::backend::ComputeUserInfo, compute, http, scram};
+use crate::{
+    auth::backend::ComputeUserInfo, compute, console::messages::ColdStartInfo, http, scram,
+};
 use crate::{
     cache::Cached,
     context::RequestMonitoring,
@@ -254,6 +256,7 @@ impl super::Api for Api {
         if permit.should_check_cache() {
             if let Some(cached) = self.caches.node_info.get(&key) {
                 info!(key = &*key, "found cached compute node info");
+                ctx.set_cold_start_info(ColdStartInfo::Warm);
                 return Ok(cached);
             }
         }

proxy/src/context.rs

@@ -111,6 +111,10 @@ impl RequestMonitoring {
         )
     }
 
+    pub fn set_cold_start_info(&mut self, info: ColdStartInfo) {
+        self.cold_start_info = Some(info);
+    }
+
     pub fn set_project(&mut self, x: MetricsAuxInfo) {
         self.set_endpoint_id(x.endpoint_id);
         self.branch = Some(x.branch_id);

proxy/src/context/parquet.rs

@@ -93,7 +93,7 @@ struct RequestData {
     /// Or if we make it to proxy_pass
     success: bool,
     /// Indicates if the cplane started the new compute node for this request.
-    cold_start_info: Option<String>,
+    cold_start_info: Option<&'static str>,
     /// Tracks time from session start (HTTP request/libpq TCP handshake)
     /// Through to success/failure
     duration_us: u64,
@@ -121,10 +121,12 @@ impl From<RequestMonitoring> for RequestData {
             region: value.region,
             error: value.error_kind.as_ref().map(|e| e.to_metric_label()),
             success: value.success,
-            cold_start_info: value
-                .cold_start_info
-                .as_ref()
-                .map(|x| serde_json::to_string(x).unwrap_or_default()),
+            cold_start_info: value.cold_start_info.as_ref().map(|x| match x {
+                crate::console::messages::ColdStartInfo::Unknown => "unknown",
+                crate::console::messages::ColdStartInfo::Warm => "warm",
+                crate::console::messages::ColdStartInfo::PoolHit => "pool_hit",
+                crate::console::messages::ColdStartInfo::PoolMiss => "pool_miss",
+            }),
             duration_us: SystemTime::from(value.first_packet)
                 .elapsed()
                 .unwrap_or_default()
@@ -458,7 +460,7 @@ mod tests {
             region: "us-east-1",
             error: None,
             success: rng.gen(),
-            cold_start_info: Some("no".into()),
+            cold_start_info: Some("no"),
             duration_us: rng.gen_range(0..30_000_000),
         }
     }

proxy/src/serverless/backend.rs

@@ -9,6 +9,7 @@ use crate::{
     config::ProxyConfig,
     console::{
         errors::{GetAuthInfoError, WakeComputeError},
+        messages::ColdStartInfo,
         CachedNodeInfo,
     },
     context::RequestMonitoring,
@@ -83,6 +84,7 @@ impl PoolingBackend {
         };
 
         if let Some(client) = maybe_client {
+            ctx.set_cold_start_info(ColdStartInfo::Warm);
             return Ok(client);
         }
         let conn_id = uuid::Uuid::new_v4();