Enterprise Software

Use slave catalogs to minimize NDS WAN traffic

Catalogs can help speed NDS searches, but in a distributed network, they may slow down remote sites. In this Daily Feature, I'll explain how to use slave catalogs to minimize WAN traffic while still taking advantage of the Catalog Services.


On a large network, you probably have dozens of containers with hundreds of objects, along with several servers scattered over multiple locations. Finding anything in such a diverse network can be difficult. Catalogs can help you find NDS objects, but in a distributed environment, the catalog dredging process can quickly flood a WAN, which in turn can slow down your network and prevent users from being able to do their jobs. But you can set up slave catalogs in multiple locations that mirror your master catalogs to help minimize NDS WAN traffic. In this Daily Feature, I will explain how slave catalogs work and how you can create and use them for your remote locations.

How slave catalogs work
In the Daily Drill Down “Speed NDS searches with Catalog Services,” I showed you how catalogs can help you find NDS objects in large NDS trees. In it, I explained that you can create two types of catalogs: master catalogs and slave catalogs; however, the article mostly dealt with master catalogs and how they can be used to speed NDS searches.

If you have servers spread out over multiple locations, though, you should take advantage of slave catalogs. Slave catalogs contain the same information as master catalogs, but they gather that information a different way. Master catalogs receive their information from the dredger, which searches the entire NDS database for the information you want to place in the catalog. Slave catalogs receive information directly from master catalogs.

This works great for remote locations because the dredger can put a lot of stress on the network, causing a lot of network traffic while completing searches to fill a master catalog. But slave catalogs can be put in any partition of an NDS tree, ideally partitions in remote locations. As soon as the dredger fills out a master catalog, that catalog uses NDS replication to fill out the slave catalog.

Creating slave catalogs
You create a slave catalog using NetWare Administrator. Log on to your administrative workstation as a user with administrator rights and start NetWare Administrator. When it loads, select the container where you want to create the slave catalog object. You can create the slave anywhere in the NDS tree; it doesn’t have to be in the same container that holds the master catalog.

Right-click the container and select Create. When the New Object window appears, choose the NDSCat:Slave Catalog object icon and click OK. In the Create Catalog dialog box, specify the catalog name, check Define Additional Attributes, and then click Create.

When the Create Catalog window appears, enter the name for your slave catalog in the Catalog Name field. Even though you can distinguish master catalogs from slave catalogs in NetWare Administrator based on their differing icons, you may want to name the slave catalog so that you can quickly tell that it’s a slave, such as TPG-SlaveCatalog. Whatever name you choose needs to be a unique name; it must be different than the master catalog. After you’ve entered the name for the catalog, select the Define Additional Properties check box and click Create.

You’ll then see the Properties notebook for the new slave catalog object appear. There are only three tabs in the notebook: Identification, Summary, and Log View.

First, associate the slave catalog with a master catalog. Click the Browse button (the one that has the … on it) next to the Master field and browse your NDS tree until you find the master catalog that goes with the slave you’re creating. Select the master and click OK to close the browse window.

The rest of the information on the Identification tab is optional. However, to make it easier to identify the object in the future, it’s a good idea to go ahead and fill this information out. Click OK to save the object and close the properties notebook.

You can verify that the slave catalog is associated with the master by finding the master catalog in your NDS tree, right-clicking it, and selecting Details. When the properties notebook appears for the master catalog, click the Slave Catalogs tab. Your slave catalog will appear in the Slave Catalogs list box.

Using the catalog
After you’ve created your slave catalog, you can start using it immediately. But first, make sure you’ve run the dredger for the master catalog. This will update the master catalog and cause it to populate the new slave. Ideally, you should create a schedule for the master catalog so it updates on a regular basis rather than relying on manual updates.

Next, right-click the slave catalog in NetWare Administrator and select Details. When the properties window for the slave catalog appears, click the Summary tab. On the Summary page, click Query Catalog. You can then enter your catalog query and see the results the same way you would with a master catalog.

Conclusion
Catalog Services can be quite useful to find objects in a large NDS tree. In a distributed networking environment, dredging information for master catalogs can cause unnecessary waste of network bandwidth. Using slave catalogs in remote locations, you can get the benefits of NDS catalogs without swamping your WAN with additional traffic.

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