Optimize SSL session

roles/matrix-nginx-proxy/defaults/main.yml

@@ -386,6 +386,34 @@ matrix_ssl_log_dir_path: "{{ matrix_ssl_base_path }}/log"
 matrix_ssl_pre_obtaining_required_service_name: ~
 matrix_ssl_pre_obtaining_required_service_start_wait_time_seconds: 60
 
+# Nginx Optimize SSL Session
+#
+# ssl_session_cache:
+# - Creating a cache of TLS connection parameters reduces the number of handshakes 
+#   and thus can improve the performance of application.
+# - Default session cache is not optimal as it can be used by only one worker process
+#   and can cause memory fragmentation. It is much better to use shared cache.
+# - Learn More: https://nginx.org/en/docs/http/ngx_http_ssl_module.html
+#
+# ssl_session_timeout:
+# - Nginx by default it is set to 5 minutes which is very low.
+#   should be like 4h or 1d but will require you to increase the size of cache.
+# - Learn More: 
+#     https://github.com/certbot/certbot/issues/6903
+#     https://github.com/mozilla/server-side-tls/issues/198
+#
+# ssl_session_tickets:
+# - In case of session tickets, information about session is given to the client.
+#   Enabling this improve performance also make Perfect Forward Secrecy useless.
+# - If you would instead like to use ssl_session_tickets by yourself, you can set
+#   matrix_nginx_proxy_ssl_session_tickets_off false.
+# - Learn More: https://github.com/mozilla/server-side-tls/issues/135
+#
+# Presets are taken from Mozilla's Server Side TLS Recommended configurations
+matrix_nginx_proxy_ssl_session_cache: "shared:MozSSL:10m"
+matrix_nginx_proxy_ssl_session_timeout: "1d"
+matrix_nginx_proxy_ssl_session_tickets_off: true
+
 # OCSP Stapling eliminating the need for clients to contact the CA, with the aim of improving both security and performance.
 # OCSP stapling can provide a performance boost of up to 30%
 # nginx web server supports OCSP stapling since version 1.3.7.