FIX: Don't update User#last_seen_at when PG is in readonly.

lib/auth/default_current_user_provider.rb

@@ -241,6 +241,8 @@ class Auth::DefaultCurrentUserProvider
   end
 
   def should_update_last_seen?
+    return false if Discourse.pg_readonly_mode?
+
     if @request.xhr?
       @env["HTTP_DISCOURSE_VISIBLE".freeze] == "true".freeze
     elsif !!(@env[API_KEY_ENV]) || !!(@env[USER_API_KEY_ENV])

lib/discourse.rb

@@ -355,6 +355,10 @@ module Discourse
     recently_readonly? || $redis.mget(*keys).compact.present?
   end
 
+  def self.pg_readonly_mode?
+    $redis.get(PG_READONLY_MODE_KEY).present?
+  end
+
   def self.last_read_only
     @last_read_only ||= DistributedCache.new('last_read_only', namespace: false)
   end

lib/middleware/request_tracker.rb

@@ -72,7 +72,7 @@ class Middleware::RequestTracker
 
   def self.log_request_on_site(data, host)
     RailsMultisite::ConnectionManagement.with_hostname(host) do
-      unless Discourse.readonly_mode?([Discourse::PG_READONLY_MODE_KEY])
+      unless Discourse.pg_readonly_mode?
         log_request(data)
       end
     end