From 9caeae391e85e0dbd99e3092ab6ec687c95bb07e Mon Sep 17 00:00:00 2001
From: Yingwen <realevenyag@gmail.com>
Date: Thu, 6 Nov 2025 16:48:59 +0800
Subject: [PATCH] chore: print root cause in opendal logging interceptor
 (#7183)

* chore: print root cause in opendal

Signed-off-by: evenyag <realevenyag@gmail.com>

* refactor: extract a function root_source() to get the cause

Signed-off-by: evenyag <realevenyag@gmail.com>

---------

Signed-off-by: evenyag <realevenyag@gmail.com>
---
 src/common/error/src/lib.rs  | 16 ++++++++++++++++
 src/object-store/src/util.rs |  6 ++++--
 2 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/src/common/error/src/lib.rs b/src/common/error/src/lib.rs
index 0052d70cf3..18e6a0c9ae 100644
--- a/src/common/error/src/lib.rs
+++ b/src/common/error/src/lib.rs
@@ -45,3 +45,19 @@ pub fn from_err_code_msg_to_header(code: u32, msg: &str) -> HeaderMap {
     header.insert(GREPTIME_DB_HEADER_ERROR_MSG, msg);
     header
 }
+
+/// Returns the external root cause of the source error (exclude the current error).
+pub fn root_source(err: &dyn std::error::Error) -> Option<&dyn std::error::Error> {
+    // There are some divergence about the behavior of the `sources()` API
+    // in https://github.com/rust-lang/rust/issues/58520
+    // So this function iterates the sources manually.
+    let mut root = err.source();
+    while let Some(r) = root {
+        if let Some(s) = r.source() {
+            root = Some(s);
+        } else {
+            break;
+        }
+    }
+    root
+}
diff --git a/src/object-store/src/util.rs b/src/object-store/src/util.rs
index 00858eb74a..a402b8237c 100644
--- a/src/object-store/src/util.rs
+++ b/src/object-store/src/util.rs
@@ -16,6 +16,7 @@ use std::fmt::Display;
 use std::path;
 use std::time::Duration;
 
+use common_error::root_source;
 use common_telemetry::{debug, error, info, warn};
 use opendal::layers::{
     LoggingInterceptor, LoggingLayer, RetryInterceptor, RetryLayer, TracingLayer,
@@ -174,11 +175,12 @@ impl LoggingInterceptor for DefaultLoggingInterceptor {
         err: Option<&opendal::Error>,
     ) {
         if let Some(err) = err {
+            let root = root_source(err);
             // Print error if it's unexpected, otherwise in error.
             if err.kind() == ErrorKind::Unexpected {
                 error!(
                     target: LOGGING_TARGET,
-                    "service={} name={} {}: {operation} {message} {err:#?}",
+                    "service={} name={} {}: {operation} {message} {err:#?}, root={root:#?}",
                     info.scheme(),
                     info.name(),
                     LoggingContext(context),
@@ -186,7 +188,7 @@ impl LoggingInterceptor for DefaultLoggingInterceptor {
             } else {
                 debug!(
                     target: LOGGING_TARGET,
-                    "service={} name={} {}: {operation} {message} {err}",
+                    "service={} name={} {}: {operation} {message} {err}, root={root:?}",
                     info.scheme(),
                     info.name(),
                     LoggingContext(context),