Introduce control over how often SolidCable queries db

.env.example

@@ -8,6 +8,11 @@ RAILS_ENV=development
 MAX_THREADS=2
 WEB_CONCURRENCY=2
 
+# How often should SOLID_CABLE poll the database for new ActionCable messages.
+# You may need to dial it back if you are overloading the database.
+SOLID_CABLE_POLLING=0.1.seconds
+
+
 # This makes Quepid run only on SSL, including all interactions
 # with search engines on SSL.  If FORCE_SSL is false, then Quepid will switch
 # between http and https based on the url of the search engine for the main

config/cable.yml

@@ -10,9 +10,9 @@ development:
   #connects_to:
   #  database:
   #    writing: cable
-  polling_interval: 5.seconds
+  polling_interval: <%= ENV.fetch("SOLID_CABLE_POLLING", '0.1.seconds') %>
   message_retention: 1.day
-  silence_polling: false
+  silence_polling: true
 
 test:
   adapter: test
@@ -24,6 +24,6 @@ production:
   #connects_to:
   #  database:
   #    writing: cable
-  polling_interval: 5.seconds
+  polling_interval: <%= ENV.fetch("SOLID_CABLE_POLLING", '0.1.seconds') %>
   message_retention: 1.day
-  silence_polling: false
+  silence_polling: true

docs/operating_documentation.md

@@ -7,6 +7,7 @@ This document explains how Quepid can be operated and configured.
 - [Setting up a Context Path](#setting-up-a-context-path)
 - [Mail](#mail)
 - [OAuth](#OAuth)
+- [Managing Websocket Load](#managing-websocket-load)
 - [Legal Pages & GDPR](#legal-pages-&-gdpr)
 - [User Tracking](#user-tracking)
 - [Heathcheck Endpoint](#healthcheck)
@@ -148,6 +149,13 @@ We *assume* that the client definition in Keycloak will be named `quepid`, you c
 
 Keycloak 17+ removes the `/auth` portion of the url.  If you are using earlier versions of keycloak, you need to set `base_url:'/auth'` in devise.rb.
 
+## Managing Websocket Load
+
+Quepid uses [SolidCable]() to back the websocket messaging that drives some asynchrnous communication. The state is managed in the database.
+
+By default we issue a query every tenth of a second, which can overload your database.
+
+Set `SOLID_CABLE_POLLING` to `1.seconds` or even `5.seconds` to change how often updates are checked for.  The default is `0.1.seconds`.
 
 
 ## Legal Pages & GDPR