Merge pull request #8685 from blockscout/vb-fix-pool-size

Fix db pool size exceeds Postgres max connections

CHANGELOG.md

@@ -6,6 +6,8 @@
 
 ### Fixes
 
+- [#8685](https://github.com/blockscout/blockscout/pull/8685) - Fix db pool size exceeds Postgres max connections
+
 ### Chore
 
 <details>

apps/explorer/lib/explorer/application.ex

@@ -47,9 +47,6 @@ defmodule Explorer.Application do
     base_children = [
       Explorer.Repo,
       Explorer.Repo.Replica1,
-      Explorer.Repo.Account,
-      Explorer.Repo.PolygonEdge,
-      Explorer.Repo.RSK,
       Explorer.Vault,
       Supervisor.child_spec({SpandexDatadog.ApiServer, datadog_opts()}, id: SpandexDatadog.ApiServer),
       Supervisor.child_spec({Task.Supervisor, name: Explorer.HistoryTaskSupervisor}, id: Explorer.HistoryTaskSupervisor),
@@ -93,6 +90,7 @@ defmodule Explorer.Application do
   end
 
   defp configurable_children do
+    configurable_children_set =
       [
         configure(Explorer.ExchangeRates),
         configure(Explorer.ExchangeRates.TokenExchangeRates),
@@ -130,6 +128,24 @@ defmodule Explorer.Application do
         configure(Explorer.Chain.Cache.RootstockLockedBTC)
       ]
       |> List.flatten()
+
+    repos_by_chain_type() ++ account_repo() ++ configurable_children_set
+  end
+
+  defp repos_by_chain_type do
+    if Mix.env() == :test do
+      [Explorer.Repo.PolygonEdge, Explorer.Repo.RSK]
+    else
+      []
+    end
+  end
+
+  defp account_repo do
+    if System.get_env("ACCOUNT_DATABASE_URL") || Mix.env() == :test do
+      [Explorer.Repo.Account]
+    else
+      []
+    end
   end
 
   defp should_start?(process) do

config/runtime/dev.exs

@@ -74,14 +74,18 @@ config :explorer, Explorer.Repo.PolygonEdge,
   database: database,
   hostname: hostname,
   url: System.get_env("DATABASE_URL"),
-  pool_size: ConfigHelper.parse_integer_env_var("POLYGON_EDGE_POOL_SIZE", 10)
+  # actually this repo is not started, and its pool size remains unused.
+  # separating repos for different CHAIN_TYPE is implemented only for the sake of keeping DB schema update relevant to the current chain type
+  pool_size: 1
 
 # Configure Rootstock database
 config :explorer, Explorer.Repo.RSK,
   database: database,
   hostname: hostname,
   url: System.get_env("DATABASE_URL"),
-  pool_size: pool_size
+  # actually this repo is not started, and its pool size remains unused.
+  # separating repos for different CHAIN_TYPE is implemented only for the sake of keeping DB schema update relevant to the current chain type
+  pool_size: 1
 
 variant = Variant.get()
 

config/runtime/prod.exs

@@ -27,10 +27,7 @@ config :block_scout_web, BlockScoutWeb.Endpoint,
 ### Explorer ###
 ################
 
-pool_size =
+pool_size = ConfigHelper.parse_integer_env_var("POOL_SIZE", 50)
-  if System.get_env("DATABASE_READ_ONLY_API_URL"),
-    do: ConfigHelper.parse_integer_env_var("POOL_SIZE", 50),
-    else: ConfigHelper.parse_integer_env_var("POOL_SIZE", 40)
 
 # Configures the database
 config :explorer, Explorer.Repo,
@@ -38,15 +35,10 @@ config :explorer, Explorer.Repo,
   pool_size: pool_size,
   ssl: ExplorerConfigHelper.ssl_enabled?()
 
-pool_size_api =
-  if System.get_env("DATABASE_READ_ONLY_API_URL"),
-    do: ConfigHelper.parse_integer_env_var("POOL_SIZE_API", 50),
-    else: ConfigHelper.parse_integer_env_var("POOL_SIZE_API", 10)
-
 # Configures API the database
 config :explorer, Explorer.Repo.Replica1,
   url: ExplorerConfigHelper.get_api_db_url(),
-  pool_size: pool_size_api,
+  pool_size: ConfigHelper.parse_integer_env_var("POOL_SIZE_API", 50),
   ssl: ExplorerConfigHelper.ssl_enabled?()
 
 # Configures Account database
@@ -58,13 +50,17 @@ config :explorer, Explorer.Repo.Account,
 # Configures PolygonEdge database
 config :explorer, Explorer.Repo.PolygonEdge,
   url: System.get_env("DATABASE_URL"),
-  pool_size: ConfigHelper.parse_integer_env_var("POLYGON_EDGE_POOL_SIZE", 50),
+  # actually this repo is not started, and its pool size remains unused.
+  # separating repos for different CHAIN_TYPE is implemented only for the sake of keeping DB schema update relevant to the current chain type
+  pool_size: 1,
   ssl: ExplorerConfigHelper.ssl_enabled?()
 
 # Configures Rootstock database
 config :explorer, Explorer.Repo.RSK,
   url: System.get_env("DATABASE_URL"),
-  pool_size: pool_size,
+  # actually this repo is not started, and its pool size remains unused.
+  # separating repos for different CHAIN_TYPE is implemented only for the sake of keeping DB schema update relevant to the current chain type
+  pool_size: 1,
   ssl: ExplorerConfigHelper.ssl_enabled?()
 
 variant = Variant.get()