discourse/config/initializers/002-rails_failover.rb

88 lines
2.8 KiB
Ruby

# frozen_string_literal: true
if defined?(RailsFailover::Redis)
message_bus_keepalive_interval = nil
RailsFailover::Redis.on_failover do
message_bus_keepalive_interval = MessageBus.keepalive_interval
MessageBus.keepalive_interval = -1 # Disable MessageBus keepalive_interval
Discourse.received_redis_readonly!
end
RailsFailover::Redis.on_fallback do
Discourse.clear_redis_readonly!
Discourse.request_refresh!
MessageBus.keepalive_interval = message_bus_keepalive_interval
ObjectSpace.each_object(DistributedCache) do |cache|
cache.clear
end
SiteSetting.refresh!
end
if Rails.logger.respond_to? :chained
RailsFailover::Redis.logger = Rails.logger.chained.first
end
end
if defined?(RailsFailover::ActiveRecord)
return unless Rails.configuration.active_record_rails_failover
if Rails.configuration.multisite
if ActiveRecord::Base.current_role == ActiveRecord::Base.reading_role
RailsMultisite::ConnectionManagement.default_connection_handler =
ActiveRecord::Base.connection_handlers[ActiveRecord::Base.reading_role]
end
end
RailsFailover::ActiveRecord.on_failover do |role|
if role == ActiveRecord::Base.writing_role # Multisite master
RailsMultisite::ConnectionManagement.each_connection do
Discourse.enable_readonly_mode(Discourse::PG_READONLY_MODE_KEY)
end
else
ActiveRecord::Base.connected_to(role: role) do
Discourse.enable_readonly_mode(Discourse::PG_READONLY_MODE_KEY)
end
# Test connection to the master, and trigger master failover if needed
ActiveRecord::Base.connected_to(role: ActiveRecord::Base.writing_role) do
ActiveRecord::Base.connection.active?
rescue PG::ConnectionBad, PG::UnableToSend, PG::ServerError
RailsFailover::ActiveRecord.verify_primary(ActiveRecord::Base.writing_role)
end
end
end
RailsFailover::ActiveRecord.on_fallback do |role|
if role == ActiveRecord::Base.writing_role # Multisite master
RailsMultisite::ConnectionManagement.each_connection do
Discourse.disable_readonly_mode(Discourse::PG_READONLY_MODE_KEY)
end
else
ActiveRecord::Base.connected_to(role: role) do
Discourse.disable_readonly_mode(Discourse::PG_READONLY_MODE_KEY)
end
end
if Rails.configuration.multisite
RailsMultisite::ConnectionManagement.default_connection_handler =
ActiveRecord::Base.connection_handlers[ActiveRecord::Base.writing_role]
end
end
RailsFailover::ActiveRecord.register_force_reading_role_callback do
Discourse.redis.exists?(
Discourse::PG_READONLY_MODE_KEY,
Discourse::PG_FORCE_READONLY_MODE_KEY
)
rescue => e
if !e.is_a?(Redis::CannotConnectError)
Rails.logger.warn "#{e.class} #{e.message}: #{e.backtrace.join("\n")}"
end
false
end
end