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Chapter 5: Administering Virtual Clusters
Providing FTP Services on a Virtual Cluster
Virtual clusters that provide service on the FTP control port (port 21) have special
requirements:
FTP clusters occupy two virtual cluster slots, even though only one is displayed. This
permits server-originated FTP data connections to be rewritten by Equalizer's NAT
subsystem as they are gatewayed to the external network.
FTP data connections always have a sticky time of one second. This is necessary to
support the passive mode FTP data connection used by most web browsers.
Port redirection is not supported for FTP virtual clusters.
See "Enabling Passive FTP Connections" on page 53 for more information about
supporting passive mode FTP data connections.
Configuring a Cluster to Use Server Agents
A server agent collects performance statistics from a server. If a cluster is configured to use
server agents, Equalizer periodically contacts the server agent daemon running on each
server and downloads the server performance statistics. Server agents can also be
customized to report on server resource availability, enabling Equalizer to stop sending
requests to a server if a database or other vital resource is unavailable. For information
about writing your own server agents and using agents to monitor server resource
availability, see "Using Server Agents" on page 99.
Note – If a cluster is configured to use server agents, each server in the cluster is required to run
the appropriate server agent daemon:
NT servers. Coyote Point can supply agents for selected platforms:
To configure a cluster to use server agents:
1.
Log into the Equalizer Administration interface with edit access.
2.
In the left frame, click the name of the cluster you want to configure. The Cluster
Parameters are displayed in the right frame.
3.
Select Change Cluster Parameters from the local menu in the Cluster Parameters
frame. The Change Cluster dialog is displayed in the right frame.
68
measd
on UNIX-based servers
Equalizer Installation and Administration Guide
, ntmeasd.exe
on
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