---

Overview

Foundation Services 3.0 is supported for use with the SA Forum CLM API B.02.01, in addition to the existing CMM API.

The CLM API provides a programming interface to the Cluster Membership Service, which provides membership information about the nodes in a cluster. This API enables you to write applications that monitor the state of peer nodes. You can use the CLM API to obtain information about which node is a member of the cluster.

More information about the SA Forum/CLM API can be found at:http://www.saforum.org/

This interaction of the CLM API with the Foundation Services is illustrated in FIGURE 1-1.

---

Characteristics of the CLM API

The CLM API enables you to create highly available applications to determine which nodes are in the cluster. The main functions of the CLM API are as follows:

• Determine the availability of peer nodes

• Gather information about some or all peer nodes

The CLM API has the following multithreading characteristics:

• It is multithread safe: mutual exclusion among threads is guaranteed when critical sections of the API are executed.

• It is deferred-thread cancellation safe: All API functions are cancellation points.

• It is not asynchronous-thread cancellation safe.

• API calls cannot be interrupted by signals: If a signal is caught during a call, the call runs to completion. The call is not aborted and does not return an error in this case.

• It is not signal-handler safe: applications must not make calls to the API from signal handlers.

• It is not fork1 safe: Applications must not make calls to the API from fork handlers.

The locations of the CLM API header file and the default location for the CLM API library files differ depending on the operating system (OS) used.

• For the Solaris OS, the CLM API header file, saClm.h, is located in the /opt/SUNWcgha/include/saf directory. The default location of the CLM API library files is the /opt/SUNWcgha/lib directory.

• For the Linux OS, the cmm.h file, is located in the /opt/sun/include directory and the default location of the CMM API library files is the /opt/sun/lib directory for 32-bit applications or the /opt/sun/lib64 directory for 64-bit applications.

To access the CLM API header file and libraries for the Solaris OS, the following packages must be installed in your development environment:

• SUNWnhas-safclm-headers

• SUNWnhas-common-libs

• SUNWnhas-cmm-libs

• SUNWnhas-safclm-libs

To access the CLM API header file and libraries for Linux, the following packages must be installed in your development environment:

• sun-nhas-safclm-headers-3.0-*.x86_amd64.rpm

• sun-nhas-common-libs-3.0-*.x86_amd64.rpm

• sun-nhas-cmm-libs-3.0-*.x86_amd64.rpm

• sun-nhas-safclm-libs-3.0-*.x86_amd64.rpm

In addition, examples of using SA Forum/CLM will be provided in the SUNWnhas-safclm-headers package in the /opt/SUNWcgha/examples/SaClm_API directory (Solaris OS) or the /opt/sun/nhas/examples/SaClm_API directory (Linux OS).