|Oracle9i Directory Service Integration and Deployment Guide
Release 1 (9.0.1)
Part Number A90153-01
This chapter provides an overview of the issues you should consider before deploying a directory. For detailed information about how to deploy Oracle Internet Directory, see Part VI of Oracle Internet Directory Administrator's Guide.
The chapter covers the following topics:
The most important factor to consider when trying to decide what to store in a directory is that a directory is no substitute for a database. Because directories are designed for read operations, you should avoid using them as repositories for information that will change often. By keeping write operations in a directory to a minimum, you improve search performance. Directories are fine for single operations involving one directory entry, operations that involve relatively static information such as administrative metadata. But for transactional operations involving multiple data items and more than one operation, databases are the preferred repository.
The following are suitable candidates for directory storage:
Designing an effective directory information tree and assigning effective names for entries requires careful planning and enterprise-wide coordination. An effective directory structure incorporates the following features:
The model of a centralized, consolidated directory, and the cost savings associated, cannot be achieved without multimaster replication. Using this technology, two or more directory nodes in a network store a copy of the directory and each of them updates the directory and replicates the changes to the other nodes. Because replication can occur at the level of a naming context, the organization can avoid the administrative burden associated with partitioning the directory across different servers.
A strong, centralized directory has the following features:
Directory replication is desirable under the following circumstances:
Partitioning a directory over two or more servers is expensive because each partition must have its own plan for backup, recovery, and other data management functions. Unless the partitions of your directory are characterized by the following conditions, you should plan to replicate it.
Multimaster replication ensures that a directory is always available, and it provides a failover remedy, but you should also be aware of two other backup and recovery methods, Intelligent Client Failover and Intelligent Network Level Failover. Both of these are options where Oracle Internet Directory is installed.
Intelligent Client Failover enables clients connecting to Oracle Internet Directory to contact alternate server instances of Oracle Internet Directory if their connection to a given server instance fails.
Intelligent Network Level Failover is a technology that detects failure in the server hosting Oracle Internet Directory and reroutes connection requests to other servers. It has load balancing and failover capabilities.
Chapter 19, "Managing High Availability and Failover," in Oracle Internet Directory Administrator's Guide
Determining the load and capacity requirements of any given directory node requires foresight and careful planning. It consists of three discrete processes: capacity planning, sizing, and tuning.
This section contains the following topics:
Capacity planning involves determining the load that a directory server will bear and the capacity it must have. These are a function of the following factors:
Once you have determined the load and capacity requirements of a directory server, you can determine system requirements. Pay attention to the following factors:
Before actually using your directory, you should test it, using as test data the applications that will interact with it. Any tool that you devise for testing should use overall throughput and the average latency of operations as a measure of how tuning should be performed.
The more commonly tuned properties are:
This is contingent on the number of directory servers deployed and the number of database connections that each server opens.
In the case of Oracle Internet Directory, the biggest consumer of memory is the database cache. It should be tuned so that physical memory is always available. Too large a cache causes paging, which impedes performance. Too small a cache causes excessive disk I/O, which also impedes performance.
If the data returned by the directory resides in database tablespaces, you can do the following to improve data throughput:
When designing directory security, do the following: