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How to Integrate Key Performance Indicators from Storage Systems into SAP's Monitoring Infrastructure

by Siegfried Schmidt | SAPinsider

October 1, 2003

by Siegfried Schmidt, SAP AG SAPinsider - 2003 (Volume 4), October (Issue 4)
 

There are quite a few reasons to deploy storage systems,1 especially for the systems in a mySAP landscape. Beyond consolidation of storage demands of multiple hosts for more efficient storage management and higher availability, you also gain special features, such as non-impact backup, fast recovery, consistent online copies of an entire mySAP landscape,2 and remote data vaulting for preparation in disaster failover scenarios.3

But when it comes to monitoring your landscape, storage systems are just like any other component needed to run business processes in mySAP Business Suite — they need monitoring for performance issues. To quickly and effectively analyze and address issues, system administrators need to be alerted when a performance indicator for a component has exceeded its preset threshold.

Administrators of an SAP landscape already have the ability to monitor SAP, OS, and DB components through SAP’s monitoring suite, the Computing Center Management System (CCMS), and its CCMS Alert Monitor console. Storage vendors also provide their own set of sophisticated tools specifically for monitoring storage systems. But for most storage systems, there has not been a clear integration path to bring all this information together in this single monitor for a convenient, “one-stop” look at performance across the landscape — until now.

This article will introduce some ongoing work, in cooperation with our storage partners, to extend available storage system monitoring capabilities into SAP’s CCMS. This includes new “data suppliers” from vendors that allow CCMS to present this information. But first, let’s review some of the current challenges for monitoring data transfer and performance and how the CCMS monitoring infrastructure helps ease this process.

The Challenge of I/O Performance Analysis

To effectively prevent, identify, and correct performance troublespots, you have to cover a lot of territory. Data transfer issues can occur at any number of points along the “I/O stack”:

  • On the application level, these holdups may be caused by wasteful I/O operations due to non-optimal program code or missing DB indexes.

  • On the database level, buffers may be improperly configured and files may be laid out in a way that leads to conflicts during access of multiple concurrently running tasks.

  • Due to an inappropriate layout of file systems and logical volumes on the operating system level, database files may be crowded onto a few physical volumes (or worse, a single volume).

  • The throughput of the network may be insufficient if the reserved paths from the host to the storage system are overutilized, or if switches are used by too many hosts.

  • On the storage system level, single components such as host adapters, cache, disk adapters, physical disks, or the connections between these components may be overutilized. Where there is no evident malfunction of one of these components, I/O issues at this level can usually be solved by distributing database files on as many physical disks as possible.

While the fixes to these slowdowns can be straightforward, pinpointing the weak link and analyzing all these issues involves expert knowledge of all components along the I/O stack. The complexity of an I/O analysis increases with the possible combinations of SAP applications and heterogeneous DB, OS, and storage systems that make up a mySAP landscape.

Monitoring Your SAP Landscape with CCMS

Since it is nearly impossible to monitor all components of all systems regularly, SAP has integrated monitors for applications as well as supported DB and operating systems into the Computing Center Management System (CCMS).

CCMS uses monitor objects (e.g., “DB response time”) to track the values recorded by data suppliers, tools for data collection that are provided by each external component. CCMS then displays an alert when a certain threshold exceeds or falls below a specified value. This is displayed as a tree structure of systems, along with their monitors and alerts, in the CCMS Alert Monitor.

Along with the Alert Monitor, SAP delivers a large selection of predefined monitors that contribute to a significant reduction in the system administration workload. Beyond this, CCMS is the data collector for the Solution Manager, SAP’s standard portal for providing customer support and services.

Integration with SAP CCMS

So how do you integrate your storage system information into the CCMS?

All storage vendors already offer sophisticated tools that allow their customers to monitor almost every single detail of the storage infrastructure. Customers generally use these tools for their productive storage infrastructure.

The tools of the various vendors are similar in design. For data collection, storage system software provides a server that uses an API to gather data either directly, from the storage system itself, or indirectly, from a database that is updated by a regularly scheduled process.

Note!
To standardize this API, some vendors recently started initiatives to provide a common interface for all the various types of storage systems they offer. They also plan to extend their API for storage systems from competing vendors.

In order to close the storage- monitoring gap in SAP systems and move collected data into CCMS, you’ll need another tool — the storage system’s data supplier.

SAP’s Interface to External Monitors

As with the OS and DB components, a data supplier must be implemented to provide the storage system information to CCMS. An SAP API acts as the interface between CCMS and the data supplier tool. Currently, SAP provides these APIs for Java and for the C programming language.

A data supplier should run on UNIX and Windows NT operating systems, either together with an SAP system on the same host or on a separate host, in case demands on system resources increase.

Let’s see how this would work in practice. Figure 1 depicts the integration of storage system information into the SAP monitoring infrastructure.

Figure 1
mySAP Landscape with Storage Systems

Here we have a mySAP landscape composed of three servers and four storage systems (the gray and blue storage systems indicate systems from different vendors). The servers are devoted to SAP R/3, SAP CRM, and SAP BW, and data from these systems is distributed across the storage systems. The R/3 system is the Central Monitoring System (CEN), which gathers the information from all systems and is the source for the CCMS Alert Monitor.

Note!
Beyond pure storage system information, a CCMS integrated monitor shows how the database objects (tables, indexes, temp spaces, and LOGs) are mapped to the physical layer (disk adapter, physical disks) of the storage system.

Advantages of Integrating Storage System Information into the CCMS

System administrators will gain access to storage information within their SAP central monitoring system.

With the integration of storage information into SAP’s monitoring infrastructure, a deviation of storage key performance indicators (KPIs) from specified values can automatically lead to an alert.

All information needed in order to analyze the entire I/O stack is available in a single system. This especially eases analysis of the database layout and simplifies the usually time-consuming task of mapping database objects to the physical layer.

With an integrated CCMS Alert Monitor, you’ll have support for your storage systems from SAP service staff, who can analyze storage system-related I/O issues remotely, right from your Alert Monitor.

Remember that the server involved in the data collection process accesses storage system data in one of two ways:

  • Directly from the storage system — Here, a server that is connected to the storage systems is needed on each host 1a. A client will collect the information provided by the servers and transfer it to the data supplier 2a.

  • From a separate database — In this case, a vendor-specific collector must regularly update the database 1b. The server reads the data from the database and transfers all requested data to the data supplier 2b.

The data supplier that delivers the storage information to CCMS deploys the SAP-provided API and writes the information into shared memory 3.

The CCMS agents transfer the data from shared memory to the central monitoring system (CEN) using SAP RFC4 4. As RFC servers, the agents allow the CEN to request information (pull technology). As RFC clients, the agents send information to the CEN independently (push technology). This improves performance, as the CEN no longer needs to periodically query the agents.

Note!
The storage system’s data supplier program is OS-dependent. Each storage vendor should deliver a data supplier for all operating system platforms — or at least for the most common platforms.

For More Information

For more information on those storage system vendors that are currently working on CCMS integration and those that have already realized CCMS integration, visit http://service.sap.com/atg under “Storage Monitoring.”


1 By storage system, I mean a dedicated computer with special-purpose disk storage management functions, specifically designed to consolidate the storage demands of multiple hosts.

2 See "Create a Consistent Copy of Your Entire SAP Landscape Without Taking Systems Offline" in the July-September 2003 SAP Insider (www.SAPinsider.com).

3 See "How Storage Helps Reduce the Total Cost of Ownership for mySAP Solutions" in the January-March 2003 SAP Insider (www.SAPinsider.com).

4 Remote Function Call.


Siegfried Schmidt joined SAP in April 1989, developing SAP’s interfaces to database platforms. In 1997, he became a member of the Advanced Technology Group — a department in SAP’s support organization. In selected projects, he supported customers and the R/3 development team in optimizing mission-critical processes and performance. Currently, he develops, in cooperation with manufacturers of storage subsystems, infrastructure concepts and solutions that meet customers’ requirements of system availability, ease of administration, and performance.

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