Separate read pool and harden fanout state handling

config/config.exs

@@ -3,6 +3,9 @@ import Config
 config :postgrex, :json_library, JSON
 
 config :parrhesia,
+  database: [
+    separate_read_pool?: config_env() != :test
+  ],
   moderation_cache_enabled: true,
   relay_url: "ws://localhost:4413/relay",
   nip43: [
@@ -120,6 +123,7 @@ config :parrhesia,
   ]
 
 config :parrhesia, Parrhesia.Repo, types: Parrhesia.PostgresTypes
+config :parrhesia, Parrhesia.ReadRepo, types: Parrhesia.PostgresTypes
 
 config :parrhesia, ecto_repos: [Parrhesia.Repo]
 

config/dev.exs

@@ -23,3 +23,13 @@ config :parrhesia,
          show_sensitive_data_on_connection_error: true,
          pool_size: 10
        ] ++ repo_host_opts
+
+config :parrhesia,
+       Parrhesia.ReadRepo,
+       [
+         username: System.get_env("PGUSER") || System.get_env("USER") || "agent",
+         password: System.get_env("PGPASSWORD"),
+         database: System.get_env("PGDATABASE") || "parrhesia_dev",
+         show_sensitive_data_on_connection_error: true,
+         pool_size: 10
+       ] ++ repo_host_opts

config/prod.exs

@@ -5,4 +5,9 @@ config :parrhesia, Parrhesia.Repo,
   queue_target: 1_000,
   queue_interval: 5_000
 
+config :parrhesia, Parrhesia.ReadRepo,
+  pool_size: 32,
+  queue_target: 1_000,
+  queue_interval: 5_000
+
 # Production runtime configuration lives in config/runtime.exs.

config/runtime.exs

@@ -130,6 +130,7 @@ if config_env() == :prod do
       raise "environment variable DATABASE_URL is missing. Example: ecto://USER:PASS@HOST/DATABASE"
 
   repo_defaults = Application.get_env(:parrhesia, Parrhesia.Repo, [])
+  read_repo_defaults = Application.get_env(:parrhesia, Parrhesia.ReadRepo, [])
   relay_url_default = Application.get_env(:parrhesia, :relay_url)
 
   moderation_cache_enabled_default =
@@ -148,10 +149,18 @@ if config_env() == :prod do
   default_pool_size = Keyword.get(repo_defaults, :pool_size, 32)
   default_queue_target = Keyword.get(repo_defaults, :queue_target, 1_000)
   default_queue_interval = Keyword.get(repo_defaults, :queue_interval, 5_000)
+  default_read_pool_size = Keyword.get(read_repo_defaults, :pool_size, default_pool_size)
+  default_read_queue_target = Keyword.get(read_repo_defaults, :queue_target, default_queue_target)
+
+  default_read_queue_interval =
+    Keyword.get(read_repo_defaults, :queue_interval, default_queue_interval)
 
   pool_size = int_env.("POOL_SIZE", default_pool_size)
   queue_target = int_env.("DB_QUEUE_TARGET_MS", default_queue_target)
   queue_interval = int_env.("DB_QUEUE_INTERVAL_MS", default_queue_interval)
+  read_pool_size = int_env.("DB_READ_POOL_SIZE", default_read_pool_size)
+  read_queue_target = int_env.("DB_READ_QUEUE_TARGET_MS", default_read_queue_target)
+  read_queue_interval = int_env.("DB_READ_QUEUE_INTERVAL_MS", default_read_queue_interval)
 
   limits = [
     max_frame_bytes:
@@ -629,6 +638,12 @@ if config_env() == :prod do
     queue_target: queue_target,
     queue_interval: queue_interval
 
+  config :parrhesia, Parrhesia.ReadRepo,
+    url: database_url,
+    pool_size: read_pool_size,
+    queue_target: read_queue_target,
+    queue_interval: read_queue_interval
+
   config :parrhesia,
     relay_url: string_env.("PARRHESIA_RELAY_URL", relay_url_default),
     acl: [