7.5.10.4 MySQL REST Service System Variables

The MySQL REST Service component supplies a number of system variables, which are described in this section.

Table 7.12 MySQL REST Service System Variable Summary

Variable Name	Variable Type	Variable Scope
mysql_rest_service.http_max_connections	Integer	Global
mysql_rest_service.http_max_request_body_size	Integer	Global
mysql_rest_service.http_max_response_body_size	Integer	Global
mysql_rest_service.http_port	Integer	Global
mysql_rest_service.io_worker_threads	Integer	Global
mysql_rest_service.ssl_cert	File name	Global
mysql_rest_service.ssl_cipher	File name	Global
mysql_rest_service.ssl_key	File name	Global

• mysql_rest_service.http_port

  Command-Line Format	--mysql-rest-service.http-port=port_num
  System Variable	mysql_rest_service.http_port
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	Integer
  Default Value	33443

  Configures the MySQL REST Service HTTP Port. Changes take effect on restarting the component.

• mysql_rest_service.ssl_cert

  Command-Line Format	--mysql-rest-service.ssl-cert=file_name
  System Variable	mysql_rest_service.ssl_cert
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	File name
  Default Value	empty string

  Used to configure the certificate-chain file. By default, this variable inherits the server's ssl_cert value.

  Note

  TLS configuration is mandatory. If not defined on the server or component, component registration succeeds, but asynchronous backend startup fails.

• mysql_rest_service.ssl_key

  Command-Line Format	--mysql-rest-service.ssl-key=file_name
  System Variable	mysql_rest_service.ssl_key
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	File name
  Default Value	empty string

  Used to configure the private key file file. By default, this variable inherits the server's ssl_cert value.

  Note

  TLS configuration is mandatory. If not defined on the server or component, component registration succeeds, but asynchronous backend startup fails.

• mysql_rest_service.ssl_cipher

  Command-Line Format	--mysql_rest_service.ssl_cipher=value
  System Variable	mysql_rest_service.ssl_cipher
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	File name
  Default Value	empty string

  Configures the colon-separated cipher list for TLS 1.2. By default, this variable inherits the server's ssl_cipher value.

• mysql_rest_service.io_worker_threads

  Command-Line Format	--mysql-rest-service.io-worker-threads=#
  System Variable	mysql_rest_service.io_worker_threads
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	Integer
  Default Value	0
  Minimum Value	0
  Maximum Value	1024

  Configures the number of threads that process connection, TLS, and HTTP I/O events. These are not MySQL connection threads and do not represent a THD limit.

  A value of 0 selects automatic sizing: 25% of the available logical CPUs, rounded up, with a minimum of one worker. A positive value specifies the exact worker count.

• mysql_rest_service.http_max_connections

  Command-Line Format	--mysql-rest-service.http-max-connections=#
  System Variable	mysql_rest_service.http_max_connections
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	Integer
  Default Value	1024
  Minimum Value	1
  Maximum Value	100000

  Configures a limit of active HTTP client TCP connections. A keep-alive connection counts as one active connection. Lowering the value does not terminate existing connections. When the limit is reached, new connections are closed without an HTTP 503 response.

  HTTP client connections and internal MySQL sessions do not have a one-to-one relationship. An idle HTTP connection does not itself require a THD. Sessions used for REST request execution and other data-plane work count against the shared server connection budget controlled by the server's max_connections value. When that budget is exhausted, creation of a new data-plane session fails with ER_CON_COUNT_ERROR.

  A bounded set of metadata control-plane sessions used for bootstrap, metadata readiness, and metadata monitoring may use the administrative session path. This admission exception does not grant additional SQL privileges and is not available to REST request execution or arbitrary background work

  mysql_rest_service.http_max_connections limits HTTP connections independently of max_connections.

• mysql_rest_service.http_max_request_body_size

  Command-Line Format	--mysql-rest-service.http-max-request_body_size=#
  System Variable	mysql_rest_service.http_max_request_body_size
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	Integer
  Default Value	16777216
  Minimum Value	0
  Maximum Value	2147483648

  Limits raw request-body bytes, excluding the request line and headers. A value of 0 permits only empty request bodies. If Content-Length exceeds the limit, the server responds with HTTP 413 Payload Too Large and closes the connection. Chunked or streamed bodies are checked while being read. Requests containing both Content-Length and Transfer-Encoding, or an invalid Content-Length receive HTTP 400 Bad Request and the connection is closed.

• mysql_rest_service.http_max_response_body_size

  Command-Line Format	--mysql-rest-service.http-max-response-body-size=#
  System Variable	mysql_rest_service.http_max_response_body_size
  Scope	Global
  Dynamic	Yes
  SET_VAR Hint Applies	No
  Type	Integer
  Default Value	16777216
  Minimum Value	0
  Maximum Value	2147483648

  limits response payload bytes after content encoding and excludes status lines, headers, and transfer framing. A value of `0` permits only empty response bodies. If a response exceeds the limit, the original body is not sent; the server sends HTTP `500 Internal Server Error` with an empty body and closes the connection.

  The response limit is a final HTTP-server safeguard. It does not prevent memory from being consumed while MRS constructs or serializes the response.