Bug 1038120

Summary: Admin guide: 22. L1 Cache
Product: [JBoss] JBoss Data Grid 6 Reporter: Radim Vansa <rvansa>
Component: DocumentationAssignee: Misha H. Ali <mhusnain>
Status: CLOSED CURRENTRELEASE QA Contact:
Severity: medium Docs Contact:
Priority: unspecified    
Version: 6.2.0CC: jdg-bugs, rvansa
Target Milestone: GA   
Target Release: 6.2.0   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of: Environment:
Build Name: 12532, Administration and Configuration Guide-6.2-3 Build Date: 02-12-2013 16:17:22 Topic ID: 5151-560846 [Latest]
Last Closed: 2014-01-16 00:02:11 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:

Description Radim Vansa 2013-12-04 13:17:40 UTC
22.1 About the L1 Cache

First paragraph

"The L1 cache is created when Red Hat JBoss Data Grid's cache mode is set to distribution. The L1 cache is not available with other cache modes therefore any configuration related to L1 cache is ignored."

This sounds like L1 is created by default for distribution mode. I'd set this to

"The L1 cache is available only with when Red Hat JBoss Data Grid's cache mode is set to distribution. In other cache modes any configuration related to L1 cache is ignored."

Second paragraph, typo:

"must be fetches from their owner node" -> "must be fetched from their owner node"

Third paragraph:

"The temporary location used by the L1 cache can be changed from the default location."

This is rubbish, remove the third paragraph at all and put this instead (text taken from following sections):

"Each time a key is updated an invalidation message is generated. This message is multicast to each node that contains data that corresponds to current L1 cache entries. The invalidation message ensures that each of these nodes marks the relevant entry as invalidated. Also, when the location of an entry changes in the cluster, the corresponding L1 cache entry is invalidated to prevent outdated cache entries."

22.2 L1 Cache Entries

This section should be about cache configuration, but it describes internal functionality and the heading does not match to that. Change the heading to "22.2 L1 Cache Configuration" and remove the text below the heading.

22.2.2 L1 Cache Configuration (Remote Client-Server Mode)

Please add a Note here:

"When the cache is accessed remotely via the Hot Rod protocol, the client usually accesses the owner node directly. Therefore, using L1 Cache in this setup does not offer any performance improvement and is not recommended.
Other remote clients (Memcached, REST) cannot target the owner, therefore, using L1 Cache may increase the performance (at the cost of higher memory consumption)."

22.3 L1 Cache Operations

Remove this section (with both subsections) at all - 22.3.1 should go to 22.1 (as the third paragraph) and 22.3.2 is either already mentioned before or it is rubbish (the stuff about configurable location).

Comment 5 Misha H. Ali 2014-01-16 00:02:11 UTC
The fix for this bug is now generally released and available here:

https://access.redhat.com/site/documentation/en-US/Red_Hat_JBoss_Data_Grid/6.2/index.html