ssh stop responding, processes and load average are growing

As in the subject line.
Redhat 7 - one server from time to time stops responding to ssh. The server still pings and is quite responsive but Processes are growing e.g. 1900, the load average: 1596.82, 1589.61, 1571.18

What I noticed we are flooded in messages with:

kernel: audit: audit_backlog;=65536 > audit_backlog_limit=65535
kernel: audit: audit_lost=2112805915 audit_rate_limit=0 audit_backlog_limit=65535
kernel: audit: backlog limit exceeded

any idea how to troubleshot?