discourse/config/discourse_defaults.conf
Sam 32393f72b1
PERF: backoff background requests when overloaded (#10888)
When the server gets overloaded and lots of requests start queuing server
will attempt to shed load by returning 429 errors on background requests.

The client can flag a request as background by setting the header:
`Discourse-Background` to `true`

Out-of-the-box we shed load when the queue time goes above 0.5 seconds.

The only request we shed at the moment is the request to load up a new post
when someone posts to a topic.

We can extend this as we go with a more general pattern on the client.

Previous to this change, rate limiting would "break" the post stream which
would make suggested topics vanish and users would have to scroll the page
to see more posts in the topic.

Server needs this protection for cases where tons of clients are navigated
to a topic and a new post is made. This can lead to a self inflicted denial
of service if enough clients are viewing the topic.

Due to the internal security design of Discourse it is hard for a large
number of clients to share a channel where we would pass the full post body
via the message bus.

It also renames (and deprecates) triggerNewPostInStream to triggerNewPostsInStream

This allows us to load a batch of new posts cleanly, so the controller can
keep track of a backlog

Co-authored-by: Joffrey JAFFEUX <j.jaffeux@gmail.com>
2020-10-13 16:56:03 +11:00

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#
# DO NOT EDIT THIS FILE
# If you need to make changes create a file called discourse.conf in this directory with your changes
# On import this file will be imported using ERB
#
# Discourse supports multiple mechanisms for production config.
#
# 1. You can do nothing and get these defaults (not recommended, you should at least set hostname)
# 2. You can copy this file to config/discourse.conf and amend with your settings
# 3. You can pass in config from your environment, all the settings below are available.
# Append DISCOURSE_ and upper case the setting in ENV. For example:
# to pass in db_timeout of 200 you would use DISCOURSE_DB_TIMEOUT=200
# All settings apply to production only
# connection pool size, sidekiq is set to 5, allowing an extra 3 for bg threads
db_pool = 8
# ActiveRecord connection pool timeout in milliseconds
db_timeout = 5000
# Database connection timeout in seconds
db_connect_timeout = 5
# socket file used to access db
db_socket =
# host address for db server
# This is set to blank so it tries to use sockets first
db_host =
# host address for db server when taking a backup via `pg_dump`
# Defaults to `db_host` if not configured
db_backup_host =
# port running db server, no need to set it
db_port =
# db server port to use when taking a backup via `pg_dump`
db_backup_port = 5432
# database name running discourse
db_name = discourse
# username accessing database
db_username = discourse
# password used to access the db
db_password =
# Disallow prepared statements
# see: https://github.com/rails/rails/issues/21992
db_prepared_statements = false
# host address for db replica server
db_replica_host =
# port running replica db server, defaults to 5432 if not set
db_replica_port =
db_advisory_locks = true
# hostname running the forum
hostname = "www.example.com"
# backup hostname mainly for cdn use
backup_hostname =
# address of smtp server used to send emails
smtp_address =
# port of smtp server used to send emails
smtp_port = 25
# domain passed to smtp server
smtp_domain =
# username for smtp server
smtp_user_name =
# password for smtp server
smtp_password =
# smtp authentication mechanism
smtp_authentication = plain
# enable TLS encryption for smtp connections
smtp_enable_start_tls = true
# mode for verifying smtp server certificates
# to disable, set to 'none'
smtp_openssl_verify_mode =
# load MiniProfiler in production, to be used by developers
load_mini_profiler = true
# Every how many requests should MP profile a request (aka take snapshot)
# Default is never
mini_profiler_snapshots_period = 0
# recommended, cdn used to access assets
cdn_url =
# The hostname used by the CDN to request assets
cdn_origin_hostname =
# comma delimited list of emails that have developer level access
developer_emails =
# redis server address
redis_host = localhost
# redis server port
redis_port = 6379
# redis slave server address
redis_slave_host =
# redis slave server port
redis_slave_port = 6379
# redis database
redis_db = 0
# redis password
redis_password =
# skip configuring client id for cloud providers who support no client commands
redis_skip_client_commands = false
# uses SSL for all Redis connections if true
redis_use_ssl = false
# message bus redis server switch
message_bus_redis_enabled = false
# message bus redis server address
message_bus_redis_host = localhost
# message bus redis server port
message_bus_redis_port = 6379
# message bus redis slave server address
message_bus_redis_slave_host =
# message bus redis slave server port
message_bus_redis_slave_port = 6379
# message bus redis database
message_bus_redis_db = 0
# message bus redis password
message_bus_redis_password =
# skip configuring client id for cloud providers who support no client commands
message_bus_redis_skip_client_commands = false
# enable Cross-origin Resource Sharing (CORS) directly at the application level
enable_cors = false
cors_origin = ''
# enable if you really need to serve assets in prd
serve_static_assets = false
# number of sidekiq workers (launched via unicorn master)
sidekiq_workers = 5
# adjust stylesheets to rtl (requires "rtlit" gem)
rtl_css = false
# connection reaping helps keep connection counts down, postgres
# will not work properly with huge numbers of open connections
# reap connections from pool that are older than 30 seconds
connection_reaper_age = 30
# run reap check every 30 seconds
connection_reaper_interval = 30
# set to relative URL (for subdirectory hosting)
# IMPORTANT: path must not include a trailing /
# EG: /forum
relative_url_root =
# increasing this number will increase redis memory use
# this ensures backlog (ability of channels to catch up are capped)
# message bus default cap is 1000, we are winding it down to 100
message_bus_max_backlog_size = 100
# must be a 64 byte hex string, anything else will be ignored with a warning
secret_key_base =
# fallback path for all assets which are served via the application
# used by static_controller
# in multi host setups this allows you to have old unicorn instances serve
# newly compiled assets
fallback_assets_path =
# S3 settings used for serving ALL public files
# be sure to configre a CDN as well per cdn_url
s3_bucket =
s3_region =
s3_access_key_id =
s3_secret_access_key =
s3_use_iam_profile =
s3_cdn_url =
s3_endpoint =
s3_http_continue_timeout =
s3_install_cors_rule =
### rate limits apply to all sites
max_user_api_reqs_per_minute = 20
max_user_api_reqs_per_day = 2880
max_admin_api_reqs_per_key_per_minute = 60
max_reqs_per_ip_per_minute = 200
max_reqs_per_ip_per_10_seconds = 50
# applies to asset type routes (avatars/css and so on)
max_asset_reqs_per_ip_per_10_seconds = 200
# global rate limiter will simply warn if the limit is exceeded, can be warn+block, warn, block or none
max_reqs_per_ip_mode = block
# bypass rate limiting any IP resolved as a private IP
max_reqs_rate_limit_on_private = false
# logged in DoS protection
# protection will only trigger for requests that queue longer than this amount
force_anonymous_min_queue_seconds = 1
# only trigger anon if we see more than N requests for this path in last 10 seconds
force_anonymous_min_per_10_seconds = 3
# Any requests with the headers Discourse-Background = true will not be allowed to queue
# longer than this amount of time.
# Discourse will rate limit and ask client to try again later.
background_requests_max_queue_length = 0.5
# if a message bus request queues for 100ms or longer, we will reject it and ask consumer
# to back off
reject_message_bus_queue_seconds = 0.1
# disable search if app server is queueing for longer than this (in seconds)
disable_search_queue_threshold = 1
# maximum number of posts rebaked across the cluster in the periodical job
# rebake process is very expensive, on multisite we have to make sure we never
# flood the queue
max_old_rebakes_per_15_minutes = 300
# maximum number of log messages in /logs
max_logster_logs = 1000
# during precompile update maxmind database if older than N days
# set to 0 to disable
refresh_maxmind_db_during_precompile_days = 2
# backup path containing maxmind db files
maxmind_backup_path =
# register an account at: https://www.maxmind.com/en/geolite2/signup
# then head to profile and get your license key
maxmind_license_key=
# when enabled the following headers will be added to every response:
# (note, if measurements do not exist for the header they will be omitted)
#
# X-Redis-Calls: 10
# X-Redis-Time: 1.02
# X-Sql-Calls: 102
# X-Sql-Time: 1.02
# X-Queue-Time: 1.01
enable_performance_http_headers = false
# gather JavaScript errors from clients (rate limited to 1 error per IP per minute)
enable_js_error_reporting = true
# This is probably not a number you want to touch, it controls the number of workers
# we allow mini scheduler to run. Prior to 2019 we ran a single worker.
# On extremely busy setups this could lead to situations where regular jobs would
# starve. Specifically jobs such as "run heartbeat" which keeps sidekiq running.
# Having a high number here is very low risk. Regular jobs are limited in scope and scale.
mini_scheduler_workers = 5
# enable compression on anonymous cache redis entries
# this slightly increases the cost of storing cache entries but can make it much
# cheaper to retrieve cache entries when redis is stores on a different machine to the one
# running the web
compress_anon_cache = false
# Only store entries in redis for anonymous cache if they are observed more than N times
# for a specific key
#
# This ensures there are no pathological cases where we keep storing data in anonymous cache
# never to use it, set to 1 to store immediately, set to 0 to disable anon cache
anon_cache_store_threshold = 2
# EXPERIMENTAL - not yet supported in production
# by default admins can install and amend any theme
# you may restrict it so only specific themes are approved
# in allowlist mode all theme updates must happen via git repos
# themes missing from the list are automatically disallowed
# list is a comma seperated list of git repos eg:
# https://github.com/discourse/discourse-custom-header-links.git,https://github.com/discourse/discourse-simple-theme.git
allowed_theme_repos =
# Demon::EmailSync is used in conjunction with the enable_imap site setting
# to sync N IMAP mailboxes with specific groups. It is a process started in
# unicorn.conf, and it spawns N threads (one for each multisite connection) and
# for each database spans another N threads (one for each configured group).
#
# We want this off by default so the process is not started when it does not
# need to be (e.g. development, test, certain hosting tiers)
enable_email_sync_demon = false
# we never want to queue more than 10000 digests per 30 minute block
# this can easily lead to blocking sidekiq
# on multisites we recommend a far lower number
max_digests_enqueued_per_30_mins_per_site = 10000