Exclusive cluster mode provides dedicated resources for better performance and isolation. Configuring auto-scaling rules based on metrics like Queries Per Second (QPS) and bandwidth allows the WAF cluster to automatically add or remove nodes in response to real-time traffic, which is crucial for handling unpredictable spikes. This combines dedicated resource assurance with the elasticity needed for promotional events.

Placing resources within a single VPC provides a logically isolated network. Communication between ECS instances in the same VPC occurs over Alibaba Cloud’s high-speed, low-latency internal network, which is private by default and does not traverse the public internet. Security Groups can then be used as a stateful firewall to finely control which ports and protocols are allowed between the instances, ensuring both security and optimal performance.

While disabling the key stops future misuse, an attacker may have already used the credentials. ActionTrail records all API calls made by your cloud resources. Reviewing these logs for the period between the key’s exposure and its disablement is essential to identify any unauthorized activities (e.g., spawning expensive instances, deleting data, creating new users). This forensic step is necessary for incident response, resource cleanup, and understanding the impact.

SSE-C (Server-Side Encryption with Customer-Provided Keys) meets the specific requirement for customer-managed keys. With SSE-C, you provide your own AES-256 encryption key as part of the API request when uploading an object. OSS uses this key to encrypt the data at rest but does not store the key. You must securely store and manage the key yourself and provide it again for decryption. This gives you full control over the key lifecycle.

This follows the security best practice of network segmentation and the principle of least privilege. Public subnets have route tables directing traffic to the internet gateway, making them suitable for the web tier. Private subnets have no direct internet route, protecting the app and database tiers. Security Groups act as virtual firewalls at the instance level. The rules described create a “chain” of access: the internet can only reach the Web Tier; the Web Tier can only initiate connections to the App Tier; and only the App Tier can initiate connections to the DB Tier. This limits the attack surface.

Security Center (specifically, the paid editions like Advanced or Enterprise, though Basic offers core vulnerability scanning) provides continuous, automated vulnerability detection for ECS instances. It uses a lightweight agent installed on the ECS to scan for common system and software vulnerabilities (CVEs), weak passwords, and configuration risks. It provides detailed reports, risk severity ratings, and often suggests remediation steps, which is exactly what’s needed to automate the weekly compliance check.

ActionTrail is Alibaba Cloud’s service for recording all API calls made by or on behalf of your account. It creates an immutable audit trail of management events, such as creating, modifying, or deleting resources (like an RDS instance). Each log entry includes critical details like the event time, the API name (e.g., CreateDBInstance), the requesting IP address, and the RAM user/role that made the call. This is the definitive source for compliance auditing of resource lifecycle events.

WAF rules are evaluated in order of priority. Creating a custom whitelist rule with a condition that precisely matches the trusted partner’s source IP address and setting its priority higher than the general protection rules ensures that traffic from this specific IP is allowed before it can be evaluated and potentially blocked by the stricter, more general rules. This is a precise, secure, and permanent solution that maintains security for all other traffic.

The principle of least privilege is a fundamental security concept. It means granting a user only the minimum permissions necessary to perform their job function. For a DevOps engineer, this might mean policies that allow managing ECS and VPC resources but not modifying RAM policies or accessing billing data. This minimizes the potential damage from accidental errors or if the user’s credentials are compromised. While group-based management (option C) is a good practice, it must also adhere to the principle of least privilege.

Exclusive cluster mode provides dedicated resources for better performance and isolation. Configuring auto-scaling rules based on metrics like Queries Per Second (QPS) and bandwidth allows the WAF cluster to automatically add or remove nodes in response to real-time traffic, which is crucial for handling unpredictable spikes. This combines dedicated resource assurance with the elasticity needed for promotional events.0