branch-4.1: [fix](be) Avoid per-fd stat when counting process fds in metrics #67945 - #68046
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) [fix](be) Avoid per-fd stat when counting process fds in metrics ### What problem does this PR solve? Issue Number: close #67777 Problem Summary: `DorisMetrics::_update_process_fd_num()` counts entries under `/proc/self/fd` with `entry.is_regular_file()`, which follows every symlink with a `stat()` syscall. With ~200k open fds this takes ~0.6s per run, and the hook runs under the `MetricRegistry` lock every 15 s, stalling `/metrics` scrapes for hundreds of milliseconds. This PR counts the directory entries directly (readdir only), which is about 5x cheaper while still reflecting the number of open fds. The remaining stalls (hooks running under the registry lock, stream load blocking webserver workers) are tracked as follow-ups. ### Release note None ### Check List (For Author) - Test: No need to test (with reason) - behavior preserved (fd count), only the per-entry stat syscalls are removed - Behavior changed: No - Does this need documentation: No Co-authored-by: Asthenia0412 <Asthenia0412@users.noreply.github.com>
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yiguolei
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Sep 16, 2026
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Cherry-picked from #67945