Invalid padding exceptions cause mod_cluster proxied requests over HTTPS to 502

Issue

• We're seeing random 502 failures with requests proxied through mod_cluster to JBoss over HTTPS:

[debug] ssl_engine_kernel.c(1881): OpenSSL: Read: SSLv3 read finished A
[debug] ssl_engine_kernel.c(1900): OpenSSL: Exit: failed in SSLv3 read finished A
[info] [client 127.0.0.1] SSL Proxy connect failed
[info] SSL Library Error: 336151568 error:14094410:SSL routines:SSL3_READ_BYTES:sslv3 alert handshake failure
[info] [client 127.0.0.1] Connection closed to child 0 with abortive shutdown (server localhost:443)
[error] (502)Unknown error 502: proxy: pass request body failed to 127.0.0.1:8443 (127.0.0.1)

• We have acquired the fix to the prior mod_cluster 502 bug (JBPAPP-10409, JBPAPP6-1170) yet still see this issue.
• SSL debug logging from JBoss shows the falling exception accompanies these 502s:

INFO  [stdout] (http-127.0.0.1:8443-1) 248, 178, 17, 86, 119, 76, 2, 163, 65, http-127.0.0.1:8443-1, IOException in getSession():  javax.net.ssl.SSLHandshakeException: Invalid padding