Architecture - Proxy Cache - Revision history

Docadmin at 21:21, 22 January 2010

2010-01-22T21:21:13Z

← Older revision		Revision as of 14:21, 22 January 2010
Line 1:		Line 1:
	'''''Note:''''' The content on this page reflects the state of design of a Lustre feature at a particular point in time and may contain outdated information.		'''''Note:''''' ''The content on this page reflects the state of design of a Lustre feature at a particular point in time and may contain outdated information.''

	== Definitions ==		== Definitions ==

Docadmin: Protected "Architecture - Proxy Cache" ([edit=sysop] (indefinite) [move=sysop] (indefinite))

2010-01-22T18:57:29Z

Protected "Architecture - Proxy Cache" ([edit=sysop] (indefinite) [move=sysop] (indefinite))

← Older revision	Revision as of 11:57, 22 January 2010
(No difference)

Docadmin at 00:18, 19 January 2010

2010-01-19T00:18:46Z

← Older revision		Revision as of 17:18, 18 January 2010
Line 1:		Line 1:
			'''''Note:''''' The content on this page reflects the state of design of a Lustre feature at a particular point in time and may contain outdated information.

	== Definitions ==		== Definitions ==

Docadmin: /* References */

2010-01-14T23:49:34Z

References

← Older revision		Revision as of 16:49, 14 January 2010
Line 62:		Line 62:

	UID translation		UID translation

	~~== References ==~~
	~~[[Category:Architecture]]~~
	~~[[Category:Team Rabbit]]~~

Docadmin: moved Proxy Cache to Architecture - Proxy Cache

2010-01-14T21:45:58Z

moved Proxy Cache to Architecture - Proxy Cache

← Older revision	Revision as of 14:45, 14 January 2010
(No difference)

Docadmin: 1 revision

2010-01-14T21:01:08Z

1 revision

← Older revision	Revision as of 14:01, 14 January 2010
(No difference)

Eeb at 12:12, 10 December 2007

2007-12-10T12:12:16Z

New page

== Definitions ==

; '''server''' : By default, the entire distributed entity exporting a lustre file system, both data and metadata (i.e. not the individual server processes of which it is composed).

; '''proxy''' : An intermediate server that aggregates its clients' filesystem operations onto the backend server it exports to them.

; '''caching proxy''' : A proxy that caches data and/or metadata.

; '''NV caching proxy''' : Non-volatile caching proxy - i.e. a proxy that extends its cache onto local non-volatile memory (e.g. disk, flash).

; '''disconnected operation''' : How the proxy operates when one or more of its component servers can no longer communicate with one or more components of its backend servers.

== Summary ==

A proxy uses caching and aggregation to reduce the load on its backend
server and to provide better throughput and latency to its clients.
Both volatile (in-store) and non-volatile (flash, disk) cache may be
applied in any combination (including none at all), as determined by
caching policies. This gives the proxy many uses from simple
connection aggregation to limit backend server fan-out, to filesystem
replication over a wide-area network.

A proxy translates credentials between the client side and the backend
server side. This translation implements a security policy on the
proxy's clients.

== Requirements ==

=== Cache control ===

Manage cache contention between different backends.

Cache policies
- Prefetch (what to cache aggressively)
- writeback (how much can backend lag)
- granularity
- whole F/S
- single file
- filesets?

F/S snapshot - "cut" over servers!
persistent lock pre-empts reduced coherence debate?
google uses persistent locks?

Performance

(partial) Disconnected operation

partial disconnected operation

Strong coherence

Local stable storage

Clustered - Restriping - Data and Metadata

== Use Cases ==

Connection offload (Security! SSL etc)

UID translation

== References ==
[[Category:Architecture]]
[[Category:Team Rabbit]]