User manual

Chapter 3: CacheRaQ 4 Administration

38 Cobalt CacheRaQ 4 User Manual

The Peer Settings table allows you to conﬁgure ICP peer hosts for the

CacheRaQ 4. You may wish to conﬁgure ICP if, for example, your Internet

service provider (ISP) operates an ICP-compliant cache with which you want to

peer. In the Peer Settings table, specify the following information for each peer:

the peer host name, an indication of whether the peer is a “parent” or a “sibling”

(in ICP terminology), and the HTTP and ICP port numbers to use for the

speciﬁed peer.

The default ICP port number is 3130.

Proxy-only and no-query options

There are two other conﬁguration options for a peer: “proxy-only” and

“no-query”.

If the “proxy-only” option is enabled and the CacheRaQ 4 receives an object

from elsewhere, the CacheRaQ 4 passes the object to the client but does not keep

a copy in its cache. If the “proxy-only” option is not enabled, the CacheRaQ 4

caches the object that it receives.

If the “no-query” option is enabled, the CacheRaQ 4 does not ask the other cache

servers if it has an object; it simply forwards the request and waits for a response.

If the “no-query” option is not enabled, the CacheRaQ 4 asks its parent or

siblings if it has the object. If the CacheRaQ 4 receives a negative response, it

continues asking the other peers in a round-robin format. If none of the other

cache servers has the object, the CacheRaQ 4 retrieves the object itself.

Cache Clustering can be used in conjunction with ICP in the following way:

Conﬁgure the Cluster Master as described in “Cache Cluster settings” on

page 34, but do not conﬁgure any ICP peers for it. On the Cluster Slaves,

conﬁgure the desired ICP peers as described in the previous paragraph. With this

conﬁguration, the Cluster Master sends all requests (as usual) to the Cluster

Slaves, which then query the ICP peers that have been conﬁgured.

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