After installing Elasticsearch the application failed to start with a bootstrap error.
ERROR: bootstrap checks failed max file descriptors  for elasticsearch process is too low, increase to at least  max number of threads  for user [username] is too low, increase to at least  max virtual memory areas vm.max_map_count  is too low, increase to at least 
The resolution was to modify three files.
vim /etc/security/limits.conf * soft nofile 65536 * hard nofile 131072 * soft nproc 2048 * hard nproc 4096 vim /etc/security/limits.d/90-nproc.conf #* soft nproc 1024 * soft nproc 2048 vim /etc/sysctl.conf # Added for Elasticsearch vm.max_map_count = 262144 sysctl -p
After logging off, logging back on, the user account successfully started Elasticsearch.