Explanation
"You can add secondary VNICs to an instance after it's launched. Each secondary VNIC can be in a subnet in the same VCN as the primary VNIC, or in a different subnet that is either in the same VCN or a different one. However, all the VNICs must be in the same availability domain as the instance."
https://docs.cloud.oracle.com/en-us/iaas/Content/Network/Tasks/managingVNICs.htm

Explanation
https://docs.oracle.com/en/cloud/paas/autonomous-data-warehouse-cloud/user/connect-intorduction.html#GUID To download client credentials from the Autonomous Transaction Processing Service Console:
- From the Service Console click the Administration link.
- Click Download Client Credentials (Wallet).
- On the Download Client Credentials (Wallet) page, enter a wallet password in the Password field and confirm the password in the Confirm Password field. The password must be at least 8 characters long and must include at least 1 letter and either 1 numeric character or 1 special character. This password protects the downloaded Client Credentials wallet.
- Click Download to save the client security credentials zip file. By default the filename is:
Wallet_databasename.zip. You can save this file as any filename you want. You must protect this file to prevent unauthorized database access.
The zip file includes the following:
tnsnames.ora and sqlnet.ora: Network configuration files storing connect descriptors and SQL*Net client side configuration.
cwallet.sso and ewallet.p12: Auto-open SSO wallet and PKCS12 file. PKCS12 file is protected by the wallet password provided in the UI.
keystore.jks and truststore.jks: Java keystore and truststore files. They are protected by the wallet password provided while downloading the wallet.
ojdbc.properties: Contains the wallet related connection property required for JDBC connection. This should be in the same path as tnsnames.ora.

A load balancer improves resource utilization, facilitates scaling, and helps ensure high availability. You can configure multiple load balancing policies and application-specific health checks to ensure that the load balancer directs traffic only to healthy instances. The load balancer can reduce your maintenance window by draining traffic from an unhealthy application server before you remove it from service for maintenance.
The Load Balancing service considers a server marked drain available for existing persisted sessions. New requests that are not part of an existing persisted session are not sent to that server.
Edit Drain State: Opens a dialog box in which you can change the drain state.
If you set the server's drain status to true, the load balancer stops forwarding new TCP connections and new non-sticky HTTP requests to this backend server.
This setting allows an administrator to take the server out of rotation for maintenance purposes.
e. Edit Offline State: Opens a dialog box in which you can change the offline status.
If you set the server's offline status to true, the load balance forwards no ingress traffic to this backend server.

Explanation
Dynamic groups allow you to group Oracle Cloud Infrastructure computer instances as "principal" actors (similar to user groups).
When you create a dynamic group, rather than adding members explicitly to the group, you instead define a set of matching rules to define the group members. For example, a rule could specify that all instances in a particular compartment are members of the dynamic group. The members can change dynamically as instances are launched and terminated in that compartment.
A dynamic group has no permissions until you write at least one policy that gives that dynamic group permission to either the tenancy or a compartment. When writing the policy, you can specify the dynamic group by using either the unique name or the dynamic group's OCID. Per the preceding note, even if you specify the dynamic group name in the policy, IAM internally uses the OCID to determine the dynamic group.