Let’s get back to our discussion about sizing and start thinking about some of the pieces that users might not see directly or even realize exist, but are definitely a part of the overall WCI architecture.
Aside from the Portal and Image Servers, there are three other required pieces of the WCI architecture:
• Search Server – service used for the indexing of document content, object data, and all metadata applied to both
• Automation Server – service used to run batch applications that need to be scheduled to manage content and objects (i.e. Crawlers and Identity Synchronizations)
• Database Server - services used to store all data related to WCI and its corresponding components (i.e. Users, Communities, Portlets, Folders, etc.)
Each of these services can be installed on servers together, but depending on the implementation requirements, they will more than likely need to have their own hardware. Each of the services listed above should be considered as backend services that WCI needs to manage content, user/group synchronization and object access.
When thinking about the sizing requirements for the above components, there are certain questions that need to be asked just like with the Portal and Image servers.
Using the same customer example as in the previous blog entry, we have a customer with 20,000 users that is deploying WCI as a combination intranet/extranet. As such, this means that there is going to be the need for a lot of content, many documents within the Knowledge Directory from many different sources. This content can then be made available through different kinds of portlets and through any of the searching capabilities within WCI.
EXAMPLE: Let’s assume that our customer will have more than 100,000 documents within their Knowledge Directory coming from sources like Windows File Shares, Web Sites, an internal UCM repository as well as Exchange Public Folders. The customer also owns WebCenter Collaboration and uses it primarily for intranet project management and as such has another 40,000 documents across the different active projects. This makes WCI a perfect location to provide content to many different types of users.
Automation Server
Because this content is coming from so many different sources, it definitely means that there are going to be a number of Crawler objects created and scheduled to keep all of the content up to date. Let’s assume for this example, that there are 25 crawlers running across the five different sources mentioned and that they are scheduled to run anywhere from every hour to every four hours. On top of the scheduled crawlers, the Automation Server will already have a number of housekeeping type jobs scheduled to run that are part of the Out of the Box (OOTB) maintenance for WCI. In addition, because the customer has 20,000 users, the majority of those users are probably being maintained within a third-party LDAP environment rather than as native users within WCI, as such one or more jobs may also be needed to synchronize those users with WCI so that true authentication can occur.
NOTE: Scheduling of crawler frequency very much depends on how often the sources being crawled are going to change and how the crawlers are configured. If the crawlers are set to perform both security and folder mirroring, then the crawlers may need to run more frequently, but if the sources are more for archiving, then frequency may be much longer.
With this many jobs, there is a very good chance for scheduling overlap which could cause problems with getting one job completed prior to its next run. When this starts to happen, additional Automation servers can be added and the job load spread across those additional servers. In this particular case, the customer has decided to spread their job load across two different Automation Servers where one server is dedicated to the housekeeping type of activities and user synchronization, while the second server will be used for the crawler scheduling.
NOTE: There is no hard and fast rule for determining a specific number of Automation Servers, because it will be different for each customer implementation.
Search Server
Going back to the numbers again, the customer is going to have a fairly sizeable number of documents that will need to be indexed and made available for searching. A single server will be to handle the index itself without too much problem, depending on the size of the server. However, because this WCI implementation has been designed for both intranet and extranet usage, an assumption can be made that it will be receiving a fairly high number of search and document requests. With this being the case, our customer example has decided that a clustered dual node Search Server environment will best to handle the number of requests generated by the users.
Database Server
When thinking about the Database server, there isn’t much to think for sizing purposes. WCI is not a highly transactional environment and as such, the Database server does not get worked very hard. For the majority of customer environment, our example customer included, a single Database server will suffice. However, for redundancy purposes, it is possible to cluster the database environment so that a higher level of service can be provided.
Conclusion (so far)
Using our customer example, we have the following within our architecture:
• 4 x Windows based Portal Servers
• 2 x Windows based Image Servers
• 2 x Windows based Automation Servers
• 2 x Windows based Search Servers
• 1 x Windows based Database Server
Next time we will look at the Collaboration and Analytics Server components
IMPORTANT: All recommendations above were brought together as a set of guidelines and not as a definitive architecture for all customer implementations. The number of servers suggested was based on a Windows installation and the types of hardware that are available for that type of environment. Because of the differences in hardware and operating system, the numbers could be very different if the platform were either a flavor of UNIX or Linux.
Please see the WCI certification matrix for all supported platforms: WCI Certification Worksheet
