httpd mod_proxy が 'Partial results are valid but processing is incomplete' というエラーをログに記録する

Issue

• httpd が時々、以下のようなプロキシーエラーをログに記録します。

[Thu Feb 04 10:52:58.769673 2021] [proxy_http:error] [pid 4076:tid 140127326168832] (70008)Partial results are valid but processing is incomplete: [client 127.0.0.1:34724] AH01110: error reading response

• Apache HTTPD (mod_proxy) を介してアプリケーションサーバーにファイルをアップロードしようとすると、以下のエラーが発生します。

[Wed Nov 17 17:57:56.134816 2021] [proxy_http:error] [pid 477631:tid 140092924237568] (70008)Partial results are valid but processing is incomplete: [client IP:PORT] AH02608: read request body failed to IP:PORT (IP) from IP ()
[Wed Nov 17 17:57:56.134873 2021] [proxy_http:error] [pid 477631:tid 140092924237568] [client IP:PORT] AH10154: pass request body failed to IP:PORT (IP) from IP () with status 400