Oracle HTTP Server: OHS: No locks available: apr_proc_mutex_lock failed. Attempting to shutdown process gracefully

At one of my client’s implementation, i recently noticed a lot of below errors. They have 4 ohs nodes, reverse proxying on various FMW components. 3 of them were having below error messages and overall performance was also poor. “No locks available: apr_proc_mutex_lock failed. Attempting to shutdown process gracefully”  [2016-05-15T11:24:35][opmn][TRACE:1][][OPMN] Process Ping Failed: ohs1~OHS~OHS~1 (749623442:1533343490) […]

Oracle HTTP Server: OHS: Webcache: PKI-07005: Untrusted Cert Chain: Status is down in Fusion Middleware Control but opmnctl status is up.

Summary: Recently at one of my client place, they suddenly started facing issue where In Fusion Middleware Control (/em) the instance components for Oracle HTTP Server, ‘ohs1’ and  Oracle Web Cache, ‘webcache1’  were displayed as ‘Down’ status and no metrics were available for them. Status was confirmed as Up using below command. $ORACLE_INSTANCE/bin/opmnctl status The Admin log showed below errors:- […]