Known Hub Cache and Hub Cluster Cache - Revision history

Spooky at 18:35, 5 April 2005

2005-04-05T18:35:12Z

← Older revision		Revision as of 18:35, 5 April 2005
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			[[Basic Network Maintenance\|<< Basic Network Maintenance]] \| [[Node Route Cache and Addressed Packet Forwarding\|Node Route Cache and Addressed Packet Forwarding >>]] \| [[Main_Page\|Main Page]]

	== Introduction ==		== Introduction ==

Kath: /* The Hub Cluster Cache */

2005-03-27T17:32:40Z

The Hub Cluster Cache

← Older revision		Revision as of 17:32, 27 March 2005
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	== The Hub Cluster Cache ==		== The Hub Cluster Cache ==

	The hub cluster cache is used to maintain an up to date list of neighbouring hubs,		The hub cluster cache is used to maintain an up-to-date list of neighbouring hubs,
	and the neighbouring hubs of neighbouring hubs. Thinking in terms of hops, it is an		and the neighbouring hubs of neighbouring hubs. Thinking in terms of hops, it is an
	exhaustive list of every hub which is 1 or 2 hops away from the local node (be the		exhaustive list of every hub which is 1 or 2 hops away from the local node (be the
	local node a hub or a leaf). The cluster cache is really only important when operating		local node a hub or a leaf). The cluster cache is really only important when operating
	in hub mode, however it can be maintained in leaf mode for informational purposes.		in hub mode, however, it can be maintained in leaf mode for informational purposes.

	The hub cluster cache is used by a hub when responding to a keyed remote query		The hub cluster cache is used by a hub when responding to a keyed remote query

Dcat at 23:24, 19 March 2005

2005-03-19T23:24:22Z

New page

== Introduction ==

Each Gnutella2 node must maintain a non-exhaustive cache of known hubs at the
global level, and an exhaustive cache of hubs within the neighbouring hub cluster(s).

== The Known Hub Cache ==

The known hub list is used to provide connection hints to the local connection
manager, and other nodes which connect permanently or transiently. The most
recent portion of it is exchanged with neighbours regularly.

It is also used when executing a query on the network, which involves iteratively
contacting hubs representing each hub cluster and simultaneously recording the
hubs which have been accounted for and adding those newly discovered.

The known hub cache should be highly efficient, addressable by node address and
timestamp, and sorted by the last seen timestamp of each hub record. Adding fresh
hubs should push the oldest hubs from the bottom of the cache.

It is suggested that each cached hub entry store:

* Node address
* Last seen time
* Query key, if available
* [[Datatypes|GUID]], if available
* Vendor information, if desired and available
* Throttling timing for last query key request, last query, etc

Hubs whose last seen timestamp is too old should be removed from the cache, and
should certainly never be sent to other nodes.

== The Hub Cluster Cache ==

The hub cluster cache is used to maintain an up to date list of neighbouring hubs,
and the neighbouring hubs of neighbouring hubs. Thinking in terms of hops, it is an
exhaustive list of every hub which is 1 or 2 hops away from the local node (be the
local node a hub or a leaf). The cluster cache is really only important when operating
in hub mode, however it can be maintained in leaf mode for informational purposes.

The hub cluster cache is used by a hub when responding to a keyed remote query
request, in the generation of a query acknowledgement packet (/[[QA]]). The /[[QA]]
packet contains a list of neighbouring hubs and a selection of second degree
neighbours.

The cluster cache is updated using information from /[[LNI]] and /[[KHL]] packets.