Appendix G: SMS Data Traffic

Published : September 1, 2004

While recovering the data of a failed site, data in other parts of the hierarchy continues to flow. To simplify the recovery operation, and post-recovery data mitigation, it is important to reduce the amount of data which continues to flow into to failing site. The following sections describe Microsoft® Systems Management Server (SMS) data, and how to reduce the amount of data generated by SMS during a recovery operation.

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SMS Data Types
SMS Data Traffic Types
Reducing the Traffic Load During a Site Recovery Operation

SMS Data Types

When describing SMS related backup and recovery operations, it is important to know that SMS generates and uses two different types of data:

Configuration data

This data includes information about how the site is configured. It includes details such as site boundaries, feature configuration, and object definitions. All configuration data is critical when recovering a site. If you do not configure the site that you are recovering exactly the way it was configured before it failed, then the recovery operation might fail and the site might not function properly. Object definitions, such as software distribution objects, replicate down the hierarchy. The rest of the configuration data replicates up the hierarchy.

Administrative data

This data includes software and hardware inventory data from clients and status messages generated by clients and site systems. This data can be regenerated easily. This data is important, but not critical when recovering a site. The recovered site can function properly without having all administrative data. Administrative data replicates up the hierarchy.

SMS Data Traffic Types

While the failing site cannot maintain its regular communication with the rest of the hierarchy, the site clients and other sites in the hierarchy continue to generate data such as discovery records, inventory data, and status messages. While the failing site is disconnected, backlogs of pending data are queued on various client and server systems waiting for the next opportunity to transmit. The size of the data backlog depends on many factors, but the critical factor that affects all types of traffic is how long the site is out of service.

As soon as the site server is reconnected to the rest of the hierarchy, the backlog of data is processed and, if appropriate, forwarded up the hierarchy. If the site server was offline for a long time, a large amount of data might be suddenly overflowing the network, when it all tries to reach the site server. The site server might not have the capacity to handle such an extreme amount of data. That is why it is important to minimize the backlog as much as possible and to complete the recovery operation as quickly as possible. But it is important to perform it carefully and precisely to ensure a successful operation.

The data traffic that you need to be aware of is intrasite data traffic (traffic within the site, between clients and site systems, and between site systems and the site server), and traffic between sites. Intrasite traffic consists primarily of inventory data, discovery records and client status messages. Traffic between sites includes object definitions such as package and collection definitions, site status messages, and site configuration changes.

Intrasite data traffic

Clients continue to generate hardware and software inventory data, discovery data records and status messages. This data is usually forwarded to CAPs or management points, and then to the site server. Even while the site server is offline, clients forward this data to CAPs and management points. When the site server regains functionality, the data is forwarded from the CAPs and management points to the site server to be processed. This can flood the site systems with objects that must be processed all at once.

Intra-site data traffic can originate from the site’s clients, from the site’s CAPs or management points, or from child sites. The traffic load depends on the number of clients at the failing site and at lower sites and on other factors as follows:

  • Data Discovery Records (DDR) data

    • Whether any discovery methods are enabled at the failing site or at lower sites

    • At sites where discovery methods are enabled — the scheduling of discovery methods

    • At sites where logon discovery is enabled — the frequency of user logon events

  • Hardware and software inventory data

    • Whether hardware or software inventory are enabled at the failing site or at lower sites

    • At sites where hardware inventory or software inventory are enabled — the frequency of inventory

    • At sites where software inventory is enabled — whether file collection is enabled

    • At sites where file collection is enabled — the number and the size of files being collected

  • Status messages

    • At sites where software distribution is enabled — the number and the frequency of advertisements that run on the client computers

    • At sites where software inventory or hardware inventory are enabled — the frequency of inventory

Site-to-site traffic

Sites will accumulate large amounts of data and transactions that need to be forwarded up and down the hierarchy, and then transmit when the inbound share becomes available to receive files. This traffic includes some client traffic such as DDRs that are queued for transmission up the hierarchy.

The amount of site-to-site traffic depends on the number of sites below the failing site, the number of clients in those sites, and how long the failing site is offline. It also depends on the following:

  • Site control changes

    • Number and frequency of changes made to the site configurations at sites above or below the failing site

    • Number of sites below the failing site

  • Packages and advertisements

    • The amount of software distribution related activity at the parent of the failing site, such as creating packages and advertisements, making modifications to packages, and refresh activity.

    • The number of packages and advertisements at the parent of the failing site

    • The size of the packages being distributed down from sites above the failing site

  • Collections

    • The number of custom collections created at sites above the failing site

    • The frequency of collection property changes at sites above the failing site

  • Status Messages

    • The number of sites and clients in the hierarchy below the failing site

    • The configuration of status message replication rules at the failing site and at lower sites

    • The amount of inventory and software distribution activity at the failing site and at lower sites

Reducing the Traffic Load During a Site Recovery Operation

Much of the data generated while the failing site is offline will no longer be relevant after recovering the failing site. For example, status messages reporting the inability to connect to the offline site will be irrelevant after recovering the site. Other data such as hardware and software inventory will be gathered again after the recovery operation is completed. It is recommended that you minimize the data accumulated while recovering the failing site by doing any of the followings:

  • Configure the status system:

    • At the failing site’s child sites — configure the status system not to replicate status messages to the parent site.

    • Configure status message rules at lower level sites to discard as many status messages as possible.

    For more information about status filter rules, see Chapter 14, “Using the SMS Status System,” in the Microsoft Systems Management Server 2003 Operations Guide.

  • Adjust the software and hardware inventory interval at lower level sites, so that inventory is not collected until the recovery operation is completed. Depending on the inventory schedule and on how long the recovery operation takes, this might help reduce the traffic. You need to consider the current inventory interval and the time it takes for the schedule change to take effect.

  • Use the Hierarchy Maintenance tool (PreInst.exe) to remove pending jobs entirely.