/etc/httpd/modules/mod_proxy_cluster.so: undefined symbol: ap_proxy_add_worker

Issue

• We've tried using EAP 6's mod_cluster 1.2 in RHEL 7's provided httpd, but we see an error like the following:

httpd: Syntax error on line 354 of /etc/httpd/conf/httpd.conf: Syntax error on line 2 of /etc/httpd/conf.d/mod_cluster.conf: Cannot load modules/mod_proxy_cluster.so into server: /etc/httpd/modules/mod_proxy_cluster.so: undefined symbol: ap_proxy_add_worker