[proxy]: dont log user errors from postgres (#12412)

## Problem

#8843 

User initiated sql queries are being classified as "postgres" errors,
whereas they're really user errors.

## Summary of changes

Classify user-initiated postgres errors as user errors if they are
related to a sql query that we ran on their behalf. Do not log those
errors.

proxy/src/error.rs

@@ -78,16 +78,6 @@ pub(crate) trait ReportableError: fmt::Display + Send + 'static {
     fn get_error_kind(&self) -> ErrorKind;
 }
 
-impl ReportableError for postgres_client::error::Error {
-    fn get_error_kind(&self) -> ErrorKind {
-        if self.as_db_error().is_some() {
-            ErrorKind::Postgres
-        } else {
-            ErrorKind::Compute
-        }
-    }
-}
-
 /// Flattens `Result<Result<T>>` into `Result<T>`.
 pub fn flatten_err<T>(r: Result<anyhow::Result<T>, JoinError>) -> anyhow::Result<T> {
     r.context("join error").and_then(|x| x)

proxy/src/serverless/backend.rs

@@ -404,7 +404,15 @@ impl ReportableError for HttpConnError {
     fn get_error_kind(&self) -> ErrorKind {
         match self {
             HttpConnError::ConnectionClosedAbruptly(_) => ErrorKind::Compute,
-            HttpConnError::PostgresConnectionError(p) => p.get_error_kind(),
+            HttpConnError::PostgresConnectionError(p) => {
+                if p.as_db_error().is_some() {
+                    // postgres rejected the connection
+                    ErrorKind::Postgres
+                } else {
+                    // couldn't even reach postgres
+                    ErrorKind::Compute
+                }
+            }
             HttpConnError::LocalProxyConnectionError(_) => ErrorKind::Compute,
             HttpConnError::ComputeCtl(_) => ErrorKind::Service,
             HttpConnError::JwtPayloadError(_) => ErrorKind::User,

proxy/src/serverless/sql_over_http.rs

@@ -22,7 +22,7 @@ use serde_json::Value;
 use serde_json::value::RawValue;
 use tokio::time::{self, Instant};
 use tokio_util::sync::CancellationToken;
-use tracing::{debug, error, info};
+use tracing::{Level, debug, error, info};
 use typed_json::json;
 use url::Url;
 use uuid::Uuid;
@@ -390,12 +390,35 @@ pub(crate) async fn handle(
             let line = get(db_error, |db| db.line().map(|l| l.to_string()));
             let routine = get(db_error, |db| db.routine());
 
-            tracing::info!(
-                kind=error_kind.to_metric_label(),
-                error=%e,
-                msg=message,
-                "forwarding error to user"
-            );
+            match &e {
+                SqlOverHttpError::Postgres(e)
+                    if e.as_db_error().is_some() && error_kind == ErrorKind::User =>
+                {
+                    // this error contains too much info, and it's not an error we care about.
+                    if tracing::enabled!(Level::DEBUG) {
+                        tracing::debug!(
+                            kind=error_kind.to_metric_label(),
+                            error=%e,
+                            msg=message,
+                            "forwarding error to user"
+                        );
+                    } else {
+                        tracing::info!(
+                            kind = error_kind.to_metric_label(),
+                            error = "bad query",
+                            "forwarding error to user"
+                        );
+                    }
+                }
+                _ => {
+                    tracing::info!(
+                        kind=error_kind.to_metric_label(),
+                        error=%e,
+                        msg=message,
+                        "forwarding error to user"
+                    );
+                }
+            }
 
             json_response(
                 e.get_http_status_code(),
@@ -460,7 +483,15 @@ impl ReportableError for SqlOverHttpError {
             SqlOverHttpError::ConnInfo(e) => e.get_error_kind(),
             SqlOverHttpError::ResponseTooLarge(_) => ErrorKind::User,
             SqlOverHttpError::InvalidIsolationLevel => ErrorKind::User,
-            SqlOverHttpError::Postgres(p) => p.get_error_kind(),
+            // customer initiated SQL errors.
+            SqlOverHttpError::Postgres(p) => {
+                if p.as_db_error().is_some() {
+                    ErrorKind::User
+                } else {
+                    ErrorKind::Compute
+                }
+            }
+            // proxy initiated SQL errors.
             SqlOverHttpError::InternalPostgres(p) => {
                 if p.as_db_error().is_some() {
                     ErrorKind::Service
@@ -468,6 +499,7 @@ impl ReportableError for SqlOverHttpError {
                     ErrorKind::Compute
                 }
             }
+            // postgres returned a bad row format that we couldn't parse.
             SqlOverHttpError::JsonConversion(_) => ErrorKind::Postgres,
             SqlOverHttpError::Cancelled(c) => c.get_error_kind(),
         }