HTTP 502 when uploading large file to JBoss EAP with Apache HTTPD proxy via SSL or TLS

Issue

Client receives HTTP 502 when trying to upload a large file. Apache HTTPD is configured for SSL/TLS with client and with JBoss EAP.

[Mon Mar 20 08:30:41 2017] [info] [client 192.168.1.100] Connection to child 3 established (server web.example.com:443)
[Mon Mar 20 08:30:41 2017] [info] Initial (No.1) HTTPS request received for child 3 (server web.example.com:443)
<< After lots and lots of logging (b/c a file is being uploaded) >>
[Mon Mar 20 08:30:53 2017] [debug] ssl_engine_io.c(1090): [client 192.168.1.2] SNI extension for SSL Proxy request set to 'web.example.com'
[Mon Mar 20 08:30:53 2017] [debug] ssl_engine_kernel.c(1915): OpenSSL: Handshake: start
[Mon Mar 20 08:30:53 2017] [debug] ssl_engine_kernel.c(1923): OpenSSL: Loop: before/connect initialization
[Mon Mar 20 08:30:53 2017] [debug] ssl_engine_kernel.c(1923): OpenSSL: Loop: SSLv2/v3 write client hello A
[Mon Mar 20 08:30:53 2017] [debug] ssl_engine_io.c(1950): OpenSSL: I/O error, 7 bytes expected to read on BIO#7fd619df63c0 [mem: 7fd61a4c0f20]
[Mon Mar 20 08:30:53 2017] [debug] ssl_engine_kernel.c(1952): OpenSSL: Exit: error in SSLv2/v3 read server hello A
[Mon Mar 20 08:30:53 2017] [info] [client 192.168.1.2] SSL Proxy connect failed
[Mon Mar 20 08:30:53 2017] [info] [client 192.168.1.2] Connection closed to child 0 with abortive shutdown (server web.example.com:443)
[Mon Mar 20 08:30:53 2017] [error] (502)Unknown error 502: proxy: pass request body failed to 192.168.1.2:8443 (web.example.com)
[Mon Mar 20 08:30:53 2017] [error] [client 192.168.1.100] proxy: Error during SSL Handshake with remote server returned by /myapp/editDocument.jsf, referer: https://web.example.com/myapp/documentList.jsf
[Mon Mar 20 08:30:53 2017] [error] proxy: pass request body failed to 192.168.1.2:8443 (web.example.com) from 192.168.1.100 ()
[Mon Mar 20 08:30:53 2017] [debug] proxy_util.c(2039): proxy: HTTPS: has released connection for (web.example.com)
[Mon Mar 20 08:30:53 2017] [debug] ssl_engine_kernel.c(1933): OpenSSL: Write: SSL negotiation finished successfully
[Mon Mar 20 08:30:53 2017] [info] [client 192.168.1.100] Connection closed to child 3 with standard shutdown (server web.example.com:443)