z/OS: XMS Access Method

SAS/SHARE Client Tasks

Specify XMS as the communications access method.
Specify a server name.

Specifying XMS as the Communications Access Method

XMS is the default communications access method in the z/OS operating environment. You can omit specifying the access method in a COMAMID statement and the XMS access method is assumed, by default.

If you choose to specify XMS to connect to a server, you can use the COMAMID= option in an OPTIONS statement.

options comamid=xms;

The COMAMID= option specifies the communications access method. XMS is an abbreviation for the Cross Memory Services access method.

Alternatively, you can specify the COMAMID= option in a SAS configuration file or in a SAS start-up command.

The COMAUX1= option specifies an auxiliary communications access method and can be used only in a SAS configuration file or in a SAS start-up command. If the first method that you specify in the COMAMID= option fails to access the server, the auxiliary access method is used. You can specify one auxiliary access method.

Here is the syntax for the COMAUX1= option:

COMAUX1=alternate-method

Example:

comamid=xms
comaux1=tcp

Specifying the Server

To use the XMS access method, a client and a server must run on the same computer (or node) that runs the z/OS operating environment.

In most cases, when using the XMS access method, you can specify the server using only a server ID, because the client and server sessions run on the same node. However, if you specify XMS as the primary access method and TCP as the auxiliary access method in the client session, you must use a two-level server name to accommodate the server-naming requirements of TCP.

Here is the format for the two-level node name:

SERVER=node.server-ID

The server-ID can be a maximum of eight characters in length, and it must be identical to the service name that is specified in the SERVICES file. For details, see Configuring the SERVICES File. For details about creating valid SAS names, see the SAS Language Reference: Concepts.

Example 1:

options comamid=xms comaux1=tcp;
libname mylib '.' server=srvnode.share1;

In this example, if a client/server connection succeeds using the XMS access method, the node part of the server ID is ignored and only the server ID is used. However, if the client/server connection fails using XMS, but succeeds using TCP, the two-level server name is required in order for the SERVER procedure statement to succeed. For details about the COMAUX1= option, see SAS/SHARE User's Guide. For details about the LIBNAME statement and the OPERATE procedure, see the LIBNAME statement and the OPERATE procedure in the SAS/SHARE User's Guide

Example 2:

options comamid=xms comaux1=tcp; 
libname mylib '.' server=srvnode._ _5000;

In this example, a port number rather than a server ID is specified. Two consecutive underscores (no spaces) precede the port number.

Note: A port number is valid for the TCP access method, but not for the XMS access method. If XMS is used, a port specification results in a failure. If TCP is used, a port specification is valid. [cautionend]

If the node name is not a valid SAS name, the node name can be assigned to a SAS macro variable. The macro variable is substituted for the node name in the two-level server name.

The access method evaluates the node name, in this order of priority:

SAS macro variable
acceptable node name

Example 3:

%let srvnode=mktserve.acme.com;
libname sales server=srvnode.server1;

This example shows the assignment of only the node name to a macro variable.

Note: Do not use an ampersand (&) in a two-level server name. An ampersand causes a macro variable to be resolved by the SAS parser before syntactic evaluation of the SERVER= option. [cautionend]

Example 4:

%let srvnode=mktserver.acme.com 5000;
libname sales server=srvnode;

This example shows the assignment of the node name and the server ID to a macro variable.

SAS/SHARE Client Example

The following example shows the statements that you specify in a z/OS client configuration file to access a server by using the XMS access method. The XMS access method is assumed by default. The LIBNAME statement specifies the SAS library that is accessed through the server SHARE1.

libname sasdata 'edc.prog2.sasdata' server=share1;

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