Radware Alteon, Инструкция по применению

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Alteon Application Switch Operating System Application Guide
Health Checking
482
Document ID: RDWR-ALOS-V2900_AG1302
— ARP Health Checks, page 493 —Describes how to perform health checks on Intrusion
Detection Servers (IDS) that do not have full TCP/IP stack support.
— RTSP Health Checks, page 494 —Describes how to perform RTSP health checks.
— Script-Based Health Checks, page 495 —Describes how to configure Alteon to send a series
of health-check requests to real servers or real server groups and monitor the responses.
Health checks are supported for TCP and UDP protocols, using either Binary or ASCII
content.
• Pre-defined Health Check Summary, page 502 —Lists all available out-of-the-box health check
objects.
• Failure Types, page 503 —Explains the service failed and server failed states.
• DSR Health Checks, page 505 —Describes the servers' ability to respond to the client queries
made to the Virtual server IP address when the server is in Direct Server Return (DSR) mode.
• Advanced Group Health Check, page 505 —Describes how to configure an expression to
fine-tune the selected health check for a real server group.
• Disabling the Fast Link Health Check, page 506 —Describes how to disable fast link health
checks.
Understanding Health Check Monitoring
Monitoring the availability of real servers and groups is an important component in any Application
Delivery Controller. Detection of real server failure is critical in ensuring continuous service.
Alteon allows to accurately monitor the health and performance (response time) of real servers and
the applications running on the servers using a wide range of health check types.
For increased flexibility, you can monitor server availability based on multiple health check types or
availability of additional elements by defining complex health checks (Advanced Health Checks) as
logical expression of basic health checks.
Alteon health checks are reusable objects that can be assigned to multiple monitored objects. The
health check library includes:
• Pre-defined basic health checks that can be assigned to monitored objects
• User-defined basic health checks
• User-defined advanced health checks (logical expression on basic health checks)
Alteon health checks can be assigned to:
• Server Groups—A health check assigned to a server group monitors each of the servers in the
group.
• Real Servers—A health check assigned to a real server monitors that server and overrides
health check assigned to server groups to which it belongs.