Operating considerations for DDM

 

This topic provides task-oriented information and examples that describe various aspects of DDM operation considerations.

This topic tells how the iSeries™ server functions, both as a source or target server, when it communicates with another iSeries server to perform remote file processing. It also describes the significant differences when an iSeries server is communicating with another server that is not an iSeries server.

Although this topic contains information about servers other than the iSeries server, it does not contain all the information that the other server types using DDM might need to communicate with an iSeries server. For complete information about how DDM is used with a particular remote server, refer to that server's documentation.

• Access files with DDM
  These topics describe the types of files supported by an iSeries server, when the DDM file and remote file must exist, and how to specify the names of remote files. Also included are examples and considerations for iSeries-to-iSeries and iSeries-to-System/36™ file accessing.

• Access members with DDM
  Members are supported for database I/O operations only if the target server is an iSeries server or a System/38™. Members are not supported if the target server is neither an iSeries server nor a System/38.

• Work with access methods for DDM
  Access methods control what subsets of functions can be performed after a particular remote file is opened. This might mean that an iSeries program, or a group of programs sharing a non-iSeries file, cannot do all the same operations that are possible using a file that is on the local iSeries server.

• Other DDM-related functions involving remote files
  Besides accessing remote files for data record I/O operations, other operations related to remote files can be performed. These are briefly described in these topics.

• Manage the TCP/IP server
  These topics describe how to manage the DRDA^® and DDM server jobs that communicate using sockets over TCP. It describes the subsystem in which the server runs, the objects that affect the server, and how to manage those resources.

• Cancel distributed data management work
  Whether you are testing an application, handling a user problem, or monitoring a particular device, there are times when you may want to end work that is being done on a server.

• Performance considerations for DDM
  These topics provide information to help you improve performance when using DDM and also provide some information about when to use something other than DDM to accomplish some functions.

• DDM problem analysis on the remote server
  Some functions that involve a target server may take a relatively long period of time to complete. In these situations, the target server may not appear to be functioning when it is actually waiting for a reply.

• System/36 source and target considerations for DDM
  Before an iSeries server can access files on a System/36, Level 1.0 of the DDM architecture must be installed on the System/36. These topics contain information that applies when an iSeries server is the source or target server communicating with a System/36.

• Personal computer source to iSeries target considerations for DDM
  iSeries Access Family uses DDM to allow a personal computer to communicate as a source server to access objects on an iSeries target. iSeries Access Family uses Level 3.0 of the DDM architecture stream file access support to access folder management services (FMS) folders and documents.

 

Parent topic:

Distributed data management

 

Related concepts

Additional DDM concepts

 

Related reference

CL command considerations for DDM