Understanding and Deploying LDAP Directory Services > 14. Analyzing and Reducing Costs > Ongoing Costs of Providing Your Directory Service |
Ongoing Costs of Providing Your Directory ServiceAs soon asthe directory service is in production, there are costs associated with maintaining the directory server hardware and software and the directory data. There are also costs associated with supporting end users and scaling the service to meet the needs of a growing company that is developing and deploying new directory-enabled applications. Software Upgrade CostsWhen your directory service is in production, you may need to invest in software upgrades from time to time. Upgrades may be needed for the following software packages:
Reducing Software Upgrade CostsTo reduce software upgrade costs, you can use two techniques: negotiating the best price for the upgrade and deploying the upgrade efficiently . When negotiating a price for the software upgrades, the same principles apply as whenyou make your initial software purchase. Volume discounts may be offered , so it is wise to purchase all your upgrades at once or negotiate an arrangement in which you commit to a certain number of upgrades over a set period of time. In some cases, your company may already have site licenses or support contracts in place that either cover the software you need or can be modified to include it at a nominal cost. The second way to reduce costs is to deploy your upgrade in the most efficient manner. For example, if you need to deploy a new directory-enabled client application to all your users, there are approaches you can use to minimize the amount of staff time required. You might produce a self-extracting archive that users can install themselves (many software vendors distribute their applications in this manner anyway), or you can makeuse of one of the Enterprise Management packages (Tivoli, for example) to automate the distribution and installation of software packages on end user computers. Of course, for certain types of software, such as server software, the number of places you need to install the upgrades is small, perhaps only a few servers. In that case, there isn't much efficiency to be gained by streamlining the installation process. In the case of server software, however, you can reduce overall costs to the organization by performing the upgrade in a way that provides the least disruption to end users and business processes. For example, you might schedule the upgrade during off hours when users will not be inconvenienced by unavailability of the directory. Be aware of any automated data maintenance processes that might also be scheduled during off hours, and be certain that these processes can either tolerate a temporary directory outage or be rescheduled to occur after the upgrade is complete. Hardware Upgrade and Replacement CostsAs the demandsin your directory increase, you may find it necessary to add additional capacity to existing servers or replace them entirely. The types of upgrade or replacement costs you may incur include the following:
Reducing Hardware Upgrade and Replacement CostsJust like negotiating a good initial price for your server hardware, you should try to negotiate the best price for your upgrades and replacements . You can also reduce costs when replacing your servers by reusing peripherals. For example, if your old servers use SCSI disk drives, purchasing new servers that also use SCSI disks will allow you to reuse the original disks on your new servers. Of course, you may want to purchase faster disks if performance is a concern. Similarly, using a new server that can accommodate the same memory expansion modules allows the reuse of memory from the old servers ”as long as the memory is fast enough for the new hardware. If you've purchased server hardware that can be upgraded, it may be significantly cheaper to add CPUs to an existing server than to add and manage a second server. Of course, this approach makes sense only if your directory service has become CPU-bound. If your server is I/O-bound, adding another CPU won't be much help. Costs for hardware can be amortized over the lifetime of the equipment so that the entire cost of new hardware or upgrades need not all be paid for in a single fiscal year. The same principle can also be applied to software purchases and upgrades. Monitoring CostsProper monitoring of yourdirectory service involves the upkeep of your monitoring tools as well as the ongoing staff costs involved when responding to directory problems. The following are some of the monitoring costs you may incur:
Reducing Monitoring CostsTo reduce monitoring costs, leverage any existing network management infrastructure that might be present in your organization. For example, instead of designing your own directory monitoring system that runs in parallel with an existing monitoring system, integrate your monitoring with the existing NMS. This not only allows you to avoid reinventing the wheel, but it also provides a central focus point where your users and maintenance staff can go to learn about all system failures. Data Maintenance CostsMaintainingthe data in your directory, which is discussed in Chapter 17, "Maintaining Data," is one of the most important ongoing activities you will perform. Good maintenance of your directory ensures the quality of the data, which in turn improves the usefulness of your service. Following are some of the data maintenance costs you may incur:
Reducing Data Maintenance CostsTo the greatest extent possible, automate your data management systems. The actual way you accomplish this will vary depending on how your data is managed. This section presents a few ideas. If your directory is routinely updated from some central source, such as a human resources database, automate the update process as much as you can. By using automatically scheduled processes to perform the update, you free up staff to concentrate on more useful tasks. Be certain, however, that the update process provides useful diagnostics when problems are encountered and that someone periodically reviews the diagnostic output. For more information on updating directory data from external sources, see Chapter 6, "Data Design," and Chapters 17and Chapters 22. It's quite likely that your external data sources are themselves undergoing development and modernization; you should be prepared to deal with such changes. Whenever possible, make data transformation tools flexible. For example, suppose that you need to develop a tool that transforms a table of ASCII data into an LDIF file for import into the directory. If you can make the mapping from column locations to attribute types table-driven, you can accommodate changes in the width of the columns by simply updating a table instead of changing the program code. Whenever possible and desirable, delegate responsibilities for updating data to departmental administrators or even end users. Of course, this is possible and desirable for only certain attributes, but it may make sense to make those groups responsible for some data updates. This distributes responsibility for data managementacross the organization and reduces administrative burden . It also improves the quality of the information in the directory by improving its timeliness. If you do allow departmental administrators or end users to modify certain attributes, be sure to deploy easy-to-use tools for this task. For example, suppose you have a Web-based application that allows users to change their own entries; such an application could perform validation of the values the users enter and reject invalid data with a helpful message that describes the appropriate format for the data. Backup and Restore CostsKeeping your data backed up, as discussed in Chapter 16, " Backups and Disaster Recovery," is an extremely important activity. Safeguarding your mission-critical data involves the following costs:
Reducing Backup and Restore CostsOne obvious way to reduce backup and restore costs is to use an existing backup system if one is already in place. For example, if all your servers are backed up across the network to a central tape drive, backing up the directory serversto this system will be cheaper than deploying a new backup system. The rest of this section, however, assumes that you have decided to purchase and deploy a backup system instead of using an existing system. When comparing expenses for various backup solutions, consider the cost of the hardware and the cost per byte of the media. In some cases, a backup device that costs more may actually be less expensive to operate over the long term because it is able to store more data on each individual piece of backup media. Backups protect you against catastrophic data loss. They also can be used to allow end users to recoverfrom incorrect changes made to their own directory entries. However, performing restore operations for end users can be extremely time-consuming and expensive; most backup software doesnot even provide access to individual entries in a backed-up directory. Usually, the entire directory must be restored to some other location and the required entries extracted. In general, you should avoid setting expectations that backups are to be used for anything other than recovery from catastrophic data loss. You might accomplish this by charging a fee to recover data from backup media. Disaster Recovery Plan CostsA well-designedand well- tested disaster recovery plan can protect your critical business processes from certain types of disasters, including floods, earthquakes, and fires. Development and execution of a disaster recovery plan are quite expensive; however, compared to the potential catastrophic business losses that could accompany a disaster, the development costs seem much more reasonable. For more information on disaster recovery, see Chapter 16. Following are some of the costs you may incur for your disaster recovery plan:
Reducing Disaster Recovery Plan CostsIt's certainly possibleto design a comprehensive disaster recovery plan that will protect you against most types of disasters and have your business processes back in service very quickly. However, the costs of such a plan may be prohibitive. A cost-effective DR plan takes into account the likelihood of each type of disaster. For example, you might be deciding where to locate a cold standby location for your major servers. If you are located in an area prone to earthquakes, it probably makes sense to locate the backup site far enough away so that it's unlikely that the primary and backup sites will both beaffected by a single earthquake. On the other hand, if your location is not subject to earthquakes (or other large-scale disasters such as hurricanes), you can save money by locating your backup site relatively close to your primary site. In the event that a disaster doesrender the primary site unusable, it will be less costly to transport your staff to the backup site. Also consider the acceptable time for putting a backup site into service. Maintaining a hot site certainly offers the quickest turnaround , but is also significantly more costly to maintain and test. If it's acceptable to incur 48 hours of downtime with a cold site versus four hours with a hot site, you can save money by using the cold backup site. Beyond the disaster plan itself, another way to save money is to weigh the relative costs of contracting with a DR solutions provider versus providing the backup sites yourself. If your organization has only a single location capable of supporting a backup site, it may make more sense to contract with a DR solutions provider. On the other hand, if your organization has several locations with high-speed network connectivity, sufficient power and backup generator capacity, and enough physical space, you may be able to design and deploy your own backup site at a lower cost. Support and Training CostsSupport and training enable yourand users and directory administrators to more effectively use and maintain the directory. Here is a wide range of options for providing training and support, with associated costs:
Reducing Support and Training CostsWhether your organization provides an in-house help desk or contracts with an external provider of support servers, providing your end users with better information can significantly reduce the number of support calls. Here are some suggestions for accomplishing this:
Software Support Contracts and Hardware Maintenance ContractsKeeping your directory system running smoothly is much easier if all your hardware is functioning correctly and your software is up-to-date. The types of support and maintenance contracts you might purchase include the following:
Reducing Support Contracts and Maintenance CostsHardware maintenance contracts vary widely in terms of turnaround time. If you have sufficient extra capacity in your directory service (perhaps you've deployed a number of replicas and have spare capacity) you may be able to tolerate a longer turnaround time for repair or even use a depot service arrangement. If your organization is very large, it may make sense to provide your own in-house service as just described. If you have sufficient knowledge in-house to consider this option, you may find that it is significantly less expensive than purchasing a service agreement. Finally, as with the other major purchases you make to deploy your directory service, purchasing support and maintenance agreements in larger quantities may offer some benefits when negotiating prices. Costs of Adding New Directory-Enabled ApplicationsIf your directory service is successful, it will be widely used by your employees ”and possibly by external users, if deployed in an extranet environment. Planning to accommodate new directory-enabled applications and additional load is vital to your directory's continued success. Understanding the costs of these enhancements, which are described in the following list, is therefore also necessary:
More information on directory-enabled applications is available in Chapters 20 and Chapters 21. Reducing Costs of Adding New Directory-Enabled ApplicationsWhen adding additional capacity to your directory service, use the same techniques you used to obtain the best price for your original hardware. Also, be sure to purchase appropriate hardware for continued growth. For example, if you know that in the future you will need 100Mbps networking to your servers to handle your directory traffic, don't make a large investment in 10Mbps technology that will have to be replaced . Ongoing costs of application development can be reduced by using sound software engineering techniques. Try to develop reusable components that can be shared by your developers. For example, you might be able to avoid reinventing the wheel by developing or purchasing a utility library that contains code common to all directory-enabled applications. This library can be distributed in binary form and linked with new applications. If bugs are found in the library, they can be fixed by the library maintainer, and a new library can be distributed to the application developers.
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Index terms contained in this sectionamortizinghardware upgrade costs applications adding new ongoing costs 2nd 3rd 4th 5th software upgrades backups ongoing costs 2nd media costs personnel costs reducing 2nd transportation offsite storage capacities network costs cell phone fees monitoring costs clients software upgrades costs monitoring 2nd on-call pay pager and cell phone fees reducing software maintenance ongoing adding new applications 2nd 3rd 4th 5th application upgrades backups 2nd 3rd 4th client software upgrades data maintenance 2nd 3rd 4th 5th 6th disaster recovery plans 2nd 3rd 4th 5th 6th 7th 8th hardware 2nd 3rd hardware maintenance contracts 2nd 3rd 4th operating system upgrades reducing server software upgrades software 2nd 3rd 4th 5th 6th software support contracts 2nd 3rd 4th support and training 2nd 3rd 4th 5th data maintenance ongoing costs 2nd 3rd 4th 5th 6th development costs developer training data maintenance tools costs directories costs monitoring 2nd 3rd 4th 5th 6th ongoing 2nd 3rd 4th 5th 6th 7th 8th 9th 10th 11th 12th 13th 14th 15th 16th 17th 18th 19th 20th 21st 22nd 23rd 24th 25th 26th 27th 28th 29th 30th 31st 32nd 33rd 34th 35th 36th 37th 38th 39th 40th 41st 42nd 43rd 44th 45th 46th 47th disaster recovery plans ongoing costs 2nd 3rd 4th in-house costs periodic disaster recovery service fees reducing 2nd 3rd 4th testing disk space server cost fees levied by data owners hardware ongoing costs additional network capacity disk space for servers maintenance contracts 2nd 3rd 4th memory for servers reducing 2nd server replacement upgrades amortizing costs in-house disaster recovery costs maintenance data costs 2nd 3rd 4th 5th 6th memory server costs metadirectories maintenance costs monitoring costs 2nd on-call pay pager and cell phone fees reducing software maintenance negotiating prices hardware upgrades software costs upgrades networks capacity increases costs on-call pay monitoring costs ongoing costs adding new applications 2nd 3rd reducing 2nd application upgrades backups 2nd media costs personnel costs reducing 2nd transportation and offsite storage client software upgrades data maintenance 2nd 3rd development tools fees levied by data owners metadirectories personnel costs reducing 2nd 3rd disaster recovery plans 2nd 3rd 4th in-house costs periodic disaster recovery service fees reducing 2nd 3rd 4th testing hardware additional network capacity disk space for servers memory for servers reducing 2nd server replacement hardware maintenance contracts 2nd reducing costs 2nd operating system upgrades reducing server software upgrades software 2nd 3rd reducing 2nd 3rd software support contracts 2nd reducing costs 2nd support and training 2nd 3rd developer training end users reducing 2nd owners data fees levied by pager fees monitoring costs personnel costs backups prices negotiating hardware upgrades reducing data maintenance costs 2nd 3rd hardware upgrade costs 2nd monitoring costs ongoing costs adding new applications 2nd backups 2nd disaster recovery 2nd 3rd 4th support and training 2nd support contract costs 2nd ongoing software costs 2nd 3rd negotiating prices replacement costs servers restorations ongoing costs 2nd media costs personnel costs reducing 2nd transportation and offsite storage servers memory for costs replacement costs software upgrades software applications upgrades client upgrades maintenance monitoring costs ongoing costs 2nd 3rd reducing 2nd 3rd support contracts 2nd 3rd 4th operating system upgrades server upgrades storage disk space for servers support ongoing costs 2nd 3rd end users reducing 2nd software contracts 2nd 3rd 4th testing disaster recovery training ongoing costs 2nd 3rd developer training end users reducing 2nd upgrades hardware costs 2nd 3rd negotiating costs ongoing costs applications client software operating system server software users support costs training costs |
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