"

Types of load balancing referenced:

external refers to a hardware or software based load balancing handled outside Webcenter software
MPPE the 'massively parallel portlet engine' is the portal's ability to internally load balance web services that are configured with round robin DNS
cold failover I might have the terminology wrong, but I'm referring to when you have another instance of the product installed but disabled. The instance can be turned on in the event of an ourage of the primary component, but it is not automatically available.

Portal Load balanced with an external load balancer (sticky session enabled)

References:

http://edocs.bea.com/alui/deployment/docs604/networking/c_loadbalancing.html

API

No supporting documentation, but anecdotal evidence suggests that the API service can be externally load balanced. Note that this does not mean that the collab / publisher components of the PRC are load balanced as well.

Publisher Publisher is able to be load balanced by breaking it up into components: publisher admin, publisher redirect, published content

Publisher admin

Cannot be load balanced, use cold failover

Publisher redirector

MPPE or external (this is installed on my portal server and uses the same load balancing method as the portal server, external works fine)

Published content

external

References:

http://fsanglier.blogspot.com/2008/02/alui-publisher-increase-performance.html

Collaboration External / MPPE (with collab internal clustering)
(Although i'm currently having issues wtih this and someone reported that you can do without the collab internal clustering)

Collab's API

When using the IDK to connect to collab, custom applications bypass the MPPE and communicate directly to the collab host, losing the benefit of the MPPE. In order to load balance in this situation, the collab host must use external load balancing. (is this true?)

"Search" service (the collab one) (only applies to 4.5 or newer)

Install on same servers as collab?
http://download.oracle.com/docs/cd/E13158_01/alui/collaboration/docs103/install/install.htm#i1138897

References:

http://edocs.bea.com/alui/deployment/docs604/networking/c_loadbalancing.html
http://forums.oracle.com/forums/thread.jspa?messageID=3347567�

Document Repository

External

(AD/LDAP) Identity Web Services

MPPE to the Web Services
External between Web Services and AD /LDAP servers (or use HOSTS files to point each ADAWS server to a differnet AD server?)

Search

(grid search: 6.1 or newer)The portal can load balance search requests internally. Each search node has knowledge of other nodes, so only 1 node needs to be reported to the portal. When the portal starts up, the 1 search node that is registered with the portal MUST be available.

Analytics

Analytics UI

(i'm not sure? i'm guessing anything would work here because the admin UI is pretty much read only on the database)

Analytics collector

can be load balanced (as of 2.5)

From Tim Nemceff:
"For load balancing for Analytics, that isn't officially supported yet for the UI and Administration components. It might work with sticky sessions from portal-to-analytics but that doesn't get you much. Improving the options there would be a good enhancement request.

For the collector, I think there are two important things to remember. Use broadcast mode. I've never actually seen it in unicast mode, but broadcast definitely works. Also, remember that this is all managed by Portal and Analytics - you don't use your own load balancer between Portal instances and the Analytics Collector instances."

http://download-llnw.oracle.com/docs/cd/E13158_01/alui/analytics/docs103/installALI/quickstart.html#wp1063387

Automation

Load balancing for reduncancy is not possible. However, the work can be split up Automation servers are assigned to different folders. Don't assign 2 automation servers to the same folder, as they can compete for jobs. (?)

Content Upload

(mppe / external)?
--
L.P: You can install more then one Content Upload Service and load balance it with the MPPOE. What you have to know about the MPPOE, it requests to check the URL's only when user refresh one portal page or clicks around into the portal. This means depending on your configuration the first few user could get a problem to upload a document, if some of the Content Upload Services is down, you can min. this probes, there is undocumented variable into the configuration.xml file for the WCI 10g for that purpose. The default value is 3 probes!

ALUI Directory Service

Tim Nemceff: ALUI Directory is not certified to be load balanced yet. On a separate note, ALUI Directory has a socket leak on Windows due to a bug in the version of Jrockit that ships with it. Upgrading the embedded application server for the ALUI/WCI installation to jrockit-R27.5.0-jdk1.5.0_14 will resolve it.

--
L.P: As a reporter of the bug:), would like to say, that this bug occurs also with the Sun JDK. There is a workaround already for the JRockit, which you can find in Metalink. The issue is very critical, because if you use ALUI Directory very frequently the server could crash! With the workaround there is no problem to load balance the ALUI Directory Service, but I prefer to wait for official certification.

Remote Portlet Service

(i'm gussing MPPE)

--
L.P: Yes, the MPPE is working perfect for me!



Notification

L.P: Unfortunately not at the moment! I wasn't able to find any documentation about load balancing Notification. The new one version is shipped with the WCI together not with the Collaboration any more. It uses ActiveMQ and as far as I know there is unfortunately NOT strait forward process for load balance it.