System Capacity Page

The Email > Reporting > System Capacity page provides a detailed representation of the system load, including messages in the work queue, incoming and outgoing messages (volume, size, and number), overall CPU usage, CPU usage by function, and memory page swapping information.

The System Capacity page can be used to determine the following information:

• Identify when Email Security appliances are exceeding recommended capacity; this enables you to determine when configuration optimization or additional appliances are needed.
• Identify historical trends in system behavior that point to upcoming capacity issues.
• For troubleshooting, identify which parts of the system are using the most resources.

Monitor your Email Security appliances to ensure that the capacity is appropriate to your message volumes. Over time, volume inevitably rises and appropriate monitoring ensures that additional capacity or configuration changes can be applied proactively. The most effective way to monitor system capacity is to track the overall volume, the messages in the work queue, and the incidents of Resource Conservation Mode.

• Volume:It is important to understand the “normal” message volume and the “usual” spikes in your environment. Track this data over time to measure volume growth. You can use the Incoming Mail and Outgoing Mail pages to track volume over time. For more information, see System Capacity – Incoming Mail and System Capacity – Outgoing Mail.
• Work Queue: The work queue is designed to work as a “shock absorber”— absorbing and filtering spam attacks and processing unusual increases in non-spam messages. However, the work queue can also indicate a system under stress. Prolonged and frequent work queue backups may indicate a capacity problem. You can use the System Capacity – Workqueue page to track the activity in your work queue. For more information, see System Capacity – Workqueue.
• Resource Conservation Mode: When an appliance becomes overloaded, it enters Resource Conservation Mode (RCM) and sends a CRITICAL system alert. This is designed to protect the device and allow it to process any backlog of messages. Your appliance should enter RCM infrequently and only during a very large or unusual increase in mail volume. Frequent RCM alerts may be an indication that the system is becoming overloaded. See Resource Conservation Activity.