Oracle Cloud Infrastructure Documentation

DB System Endpoints

A DB system endpoint allows client applications to connect to the database to access the data. There are different types of endpoints: primary endpoint, read endpoint, read replica endpoint, read replica load balancer endpoint, and REST endpoints.

An endpoint has an IP address, a database port, an X protocol port, and optionally a hostname label.

Primary Endpoint

Each standalone or high availability DB system has a primary endpoint. The primary endpoint allows client applications to connect to the DB system to perform read and write operations on the data stored in the DB system.

Read Endpoint

A read endpoint is optional and can be created on a standalone or high availability DB system with or without read replica. The DB system must have at least 4 OCPUs or 8 ECPUs. When a client application connects to the read endpoint, the connection is forwarded to:
  • An active read replica of the DB system that has not been excluded, if any, or
    Note

    You can provide a list of IP addresses of current or future read replicas to be excluded as backends.
  • The MySQL instance for standalone DB system or the primary instance for high availability DB system if it has no active read replica.
    Note

    This connection allows write operation without error, it does not enforce all operations are read-only.
The read endpoint and read replica load balancer share the same network load balancer, they have the same hostname and IP address values. The network load balancer distributes connections across all active backend servers. Different connections may be forwarded to different backend servers but all queries issued by the same connection are always forwarded to the same backend server. The read endpoint has the following limitations:
  • Currently the read endpoint supports up to 8 Gbps bandwidth only.
  • When you connect to the read endpoint, you cannot use the client host name or host based access control rules. In this case, the account name must consist of the user name only. See Connection Verification.
  • You cannot configure the read endpoint as a backend server of an Oracle Cloud Infrastructure Network Load Balancer.
  • During outbound replication, you cannot configure the read endpoint as the source; you can configure only the primary endpoint as the source.
  • You cannot create read endpoint on an IPv6 enabled subnet. The DB system and read endpoint must be created on an IPv4-only subnet.
  • The network load balancer has a maximum limit of about 21,500 active connections to the backend servers. This restricts the maximum number of concurrent active connections to the read endpoint to about 21,500.
  • Each TCP connection has an idle timeout of 8 hours. If the connection has no traffic between the client and server after the timeout, it is removed from the network load balancer and the client needs to reconnect.

Read Replica Endpoint

Each read replica of a DB system has a read replica endpoint. The read replica endpoint allows client applications to connect to the read replica and read the data stored in the read replica.

Read Replica Load Balancer Endpoint

A read replica load balancer endpoint is created automatically on a DB system when the first read replica is created on the DB system. When a client application connects to the read replica load balancer endpoint, the connection is forwarded to one of the active read replica endpoint of the DB system. If the read endpoint is enabled, the read replica load balancer shares the same network load balancer as the read endpoint and it functions similar to the read endpoint.

REST Endpoints

When REST is enabled on a DB system, you can create REST endpoints that are mapped to database objects. The URL of a REST endpoint has the following format:
https://<hostname>:<RESTport>/<RESTservice>/<RESTschema>/<RESTobject>
You can create multiple REST services. A REST schema is mapped to a database schema and a REST object is a table, view, or procedure that exists in the database schema of the REST schema. See Adding REST Services and Database Objects.

When you enable REST on a DB system with read replicas, REST endpoints are available on the DB system only. REST endpoints are not supported on read replicas.

You can enable REST and create REST endpoints on a target DB system of an inbound replication. But, do not enable REST on a source DB system of an outbound replication, it can cause the replication to break.