Components of NetWare Btrieve

The following sections describe the major components of server-based Btrieve:

For a list of the files that comprise NetWare Btrieve, see NetWare Btrieve 6.1x Program Files in Chapter 3, "Installing and Configuring NetWare Btrieve."

Server-Based Record Manager

The NetWare Btrieve server-based Record Manager (BTRIEVE.NLM) must be loaded on every server that accesses Btrieve files. The Btrieve NLM, which consists of a library of Btrieve function calls, handles these tasks:

Performs disk I/O for Btrieve files at the server where it resides
Provides concurrency and integrity controls on the server where it resides
Logs all Btrieve requests that result in changes to a file (if logging is enabled for that file)

Communications Programs

Btrieve provides these communications programs, described in more detail in the following sections:

BROUTER.NLM and BDROUTER.NLM---BROUTER, the NetWare Btrieve Message Router, allows server-based Btrieve applications to access Btrieve databases on remote servers. BDROUTER provides Directory Services support in a NetWare 4 environment.
BSPXCOM.NLM---The SPX communications agent.
BSPXSTUB.NLM---Module that allows you to use the Btrieve Monitor utility (BTRMON.NLM) when BSPXCOM is not loaded.
RSPXSTUB.NLM---Module that resolves external references for the Btrieve Monitor utility when BSPXCOM is not loaded.
If you want to use the Btrieve Monitor utility to monitor outgoing requests generated by BROUTER to another server, and you do not want to load BSPXCOM, load RSPXSTUB instead of BSPXSTUB.

Btrieve Message Routers

The Btrieve Message Routers (BROUTER.NLM or BDROUTER.NLM) handles outgoing requests from your server to a remote server.

The Message Routers allow a Btrieve application running as an NLM^TM on the server to communicate with remote servers on which other Btrieve NLMs are loaded. Also, the Message Routers maintain transaction concurrency controls during transactions involving Btrieve files on more than one server.

BROUTER.NLM---This is the default Message Router, which is loaded through the NetWare^® INSTALL utility. (For more information about the NetWare INSTALL utility, refer to Using the NetWare INSTALL Utility in Chapter 3, "Installing and Configuring NetWare Btrieve.")
BDROUTER.NLM---This is a Btrieve 6.x Message Router that provides Directory Services support.
NOTE: If you want Directory Services support, you need to unload BROUTER.NLM and load BDROUTER.NLM. Although you cannot use BDROUTER.NLM in a NetWare 3 environment, BDROUTER can communicate with both NetWare 3 and NetWare 4 servers.

If a server-based Btrieve application needs to access files on a remote server, the Message Router must be loaded on the local server.

When you request files from the remote server, the Message Router sends that request to BSPXCOM (discussed in the next section) on the remote server. BSPXCOM routes your request to the Btrieve NLM on the remote server and then sends the response back to the Message Router on the local server.

BSPXCOM

BSPXCOM handles incoming requests to the Btrieve NLM from a remote source. The remote source could be a requester at a workstation or the Message Router on another server. BSPXCOM must be loaded on all servers that support remote requests.

If no workstations or remote servers make requests to the local Btrieve NLM, you may not want to have BSPXCOM loaded at the local server.

For example, assume the local Btrieve NLM receives calls only from other NLMs running on the same server. In this case, you could choose not to load BSPXCOM for security reasons. (Not loading BSPXCOM allows you to restrict applications other than the ones on the local server from accessing your Btrieve files.)

BSPXSTUB and RSPXSTUB

If you do not load BSPXCOM and want to use the Btrieve Monitor utility (BTRMON.NLM), you must load either the BSPXSTUB or the RSPXSTUB communications module. These modules resolve external references for the Monitor utility that BSPXCOM would otherwise resolve.

Use the following guidelines to determine whether you need BSPXSTUB or RSPXSTUB:

If you want to use the Btrieve Monitor utility but do not want to load BSPXCOM, and the NLMs on the local server are accessing Btrieve files only on that server, load BSPXSTUB at the local server.

If you want to use the Btrieve Monitor utility to monitor outgoing requests generated by the Message Router to a remote server and you do not want to load BSPXCOM, load RSPXSTUB instead of BSPXSTUB at the local server.
NOTE: The Btrieve Monitor utility's Communication Statistics option (discussed on Monitoring SPX Activity with the Communication Statistics Option in Chapter 5, "Using NetWare Btrieve Utilities") displays SPX communication statistics. The communications module you load affects the statistics displayed.
For example, if you load BSPXCOM, you see incoming and outgoing SPX statistics for BSPXCOM. If you load BSPXSTUB, you see all zeros. If you load RSPXSTUB, you see incoming and outgoing SPX communication statistics from the Message Router.

Workstation Requesters

NetWare Btrieve provides the following requesters for applications running on the workstation:

BREQUEST.EXE---DOS Requester
BTRCALLS.DLL---OS/2 Requester
WBTRCALL.DLL---MS Windows Requester

A NetWare Btrieve Requester must be loaded at each workstation that makes Btrieve requests. The requester receives Btrieve requests from an application and relays them via BSPXCOM to the Btrieve NLM running on the server.

After the Btrieve NLM processes the request, BSPXCOM sends the results back to the requester, which forwards them to the application.

For information on starting the requester in each operating environment, refer to Configuring and Using the Requesters

NetWare Btrieve Utilities

NetWare Btrieve provides the following utilities for Btrieve file management:

BSETUP.NLM---The Btrieve Setup utility, which you use to change the settings of the NetWare Btrieve configuration options. (See Configuring NetWare Btrieve in Chapter 3, "Installing and Configuring NetWare Btrieve.")
BREBUILD.NLM---The Btrieve Rebuild utility, which you use to convert existing Btrieve 5.x files to the Btrieve 6.x file format. (As explained in Rebuilding Existing NetWare Btrieve Files in Chapter 3, "Installing and Configuring NetWare Btrieve," you can choose to run the Rebuild utility from within the Setup utility.)
BTRMON.NLM---The Btrieve Monitor utility, which you use to monitor the activity of NetWare Btrieve at the server.
BUTIL.NLM---The Btrieve Maintenance utility, which you use to import and export Btrieve data and to transfer data from one Btrieve file to another. This utility also lets you enable and disable continuous operation on your Btrieve files.
BROLLFWD.EXE for DOS, PBROLL.EXE for OS/2, and WBROLL.EXE for MS Windows---The Btrieve Roll Forward utilities recover changes made to a Btrieve file between the time of the last backup and a system failure. The Btrieve Roll Forward utilities are for workstation use only.

For more information about the Btrieve Setup and Rebuild utilities, refer to Installing and Configuring NetWare Btrieve For information about the Btrieve Monitor, Maintenance, and Roll Forward utilities, refer to Using NetWare Btrieve Utilities

Novell Directory Services Support Utility

NetWare Btrieve 6.1x includes a Novell Directory Services^TM (NDS^TM) Support utility that allows you to register Btrieve with NDS as an object of the class Btrieve Server. Using this utility, you can install or remove a Btrieve Server object from the Directory.

You can run the NDS Support utility (BDIRECT.NLM) interactively, through the Btrieve Setup utility, or from the command line.

For more information about the NDS Support utility, refer to Registering NetWare Btrieve with the Novell Directory Services in Chapter 3, "Installing and Configuring NetWare Btrieve."