Merge pull request #2351 from sap-contributions/db-connection-expiration

Support expiring of DB connections

lib/cloud_controller/config_schemas/base/api_schema.rb

@@ -89,6 +89,8 @@ class ApiSchema < VCAP::Config
               log_level: String, # debug, info, etc.
               log_db_queries: bool,
               connection_validation_timeout: Integer,
+              optional(:connection_expiration_timeout) => Integer,
+              optional(:connection_expiration_random_delay) => Integer,
               optional(:ssl_verify_hostname) => bool,
               optional(:ca_cert_path) => String,
             },

lib/cloud_controller/db.rb

@@ -38,6 +38,7 @@ def self.connect(opts, logger)
         db.extension(:query_length_logging)
       end
       db.default_collate = 'utf8_bin' if db.database_type == :mysql
+      add_connection_expiration_extension(db, opts)
       add_connection_validator_extension(db, opts)
       db
     end
@@ -56,6 +57,16 @@ def self.add_connection_validator_extension(db, opts)
       db.pool.connection_validation_timeout = opts[:connection_validation_timeout] if opts[:connection_validation_timeout]
     end
 
+    def self.add_connection_expiration_extension(db, opts)
+      if opts[:connection_expiration_timeout]
+        db.extension(:connection_expiration)
+        db.pool.connection_expiration_timeout = opts[:connection_expiration_timeout] if opts[:connection_expiration_timeout]
+        db.pool.connection_expiration_random_delay = opts[:connection_expiration_random_delay] if opts[:connection_expiration_random_delay]
+        # So that there are no existing connections without an expiration timestamp
+        db.disconnect
+      end
+    end
+
     def self.load_models(db_config, logger)
       db = connect(db_config, logger)
       DBMigrator.new(db).wait_for_migrations!