At a recent client we were using two web servers, both running IIS and the OBIEE presentation services, over the top of this a load balancer routed connections to one of the two servers based on load. We used the Oracle provided replication services to make sure that the contents of the two web catalogs running on each presentation server were kept in synch.
However we noticed over time that the replication services weren't working 100% and that some items were not present in both web catalogs.
To get around this we decided instead to use the ISAPI forwarding functionality; this allows the IIS server on one web server to forward it's presentation service connections to another server. This means that we can have two servers running IIS and accepting incoming connections, but only one running the presentation services, so only one web catalog is required and no replication has to take place.
In versions before the name change to OBIEE (i.e. Siebel Analytics 7.8 etc) this was handled via a registry key entry as below:
Path:
HKEY_LOCAL_MACHINE\Software\Siebel Systems, Inc.\Siebel Analytics\Web\7.8\ISAPI\
String value:
Name = ServerConnectString
Value = sawtcp://[server name]:9710
In OBIEE this has been replaced with a setting in the configuration file:
[Oracle BI Directory]\web\config\isapiconfig.xml
Like this:
<?xml version="1.0" encoding="utf-8"?>
<WebConfig>
<ServerInstance>
<ServerConnectInfo address="localhost" port="9710"/>
</ServerInstance>
</WebConfig>
<?xml version="1.0" encoding="utf-8"?>
<WebConfig>
<ServerInstance>
<ServerConnectInfo address="localhost" port="9710"/>
</ServerInstance>
</WebConfig>
Just change localhost to the name of the server running the presentation services that you want the IIS connections to be forwarded to.
Hi Matt,
ReplyDeleteOut of interest, is there a reason you didn't just use a shared filesystem for the web cat instead of replication? Having one PS instead of two gives you less capacity, resilience, and flexibility for planned downtime & maintenance.
cheers, rnm.
Hi rnm,
ReplyDeleteWe initially created the process on Analytics 7.7 which (as far as I am aware) does not support two Analytics Web Servers using the same web catalog.
Is this supported in OBIEE 10.1.3.x? I couldn't find it in the docs, but there is plenty missing from the docs :-)
Regards,
Matt
Hi Matt,
ReplyDeleteCheck out the OBIEE Deployment Guide (b40058.pdf) page 15 "The BI Presentation Services instances in the Oracle BI deployment may either share a common Presentation Catalog on a shared file system or the Presentation Catalog may be replicated across the BI Presentation Services instance", also page 30 - Identifying the Shared Presentation Catalog
cheers, RNM
PS is there some funny config on this comment system? It won't let me cut or paste anything!
Hi rnm,
ReplyDeleteCheers I'll check that out, sounds useful, certainly something to bear in mind in the future. I don't think that worked in Analytics 7.8 and earlier (I think the Analytics Web Server locked the catalog file - as it was one file then - and it couldn't be used by another.
As to the comments, not sure, it should just be the standard blogger comments but it's all beyond me :-)
Matt