SCSCOMPR

Client/server data compression

The SCSCOMPR environment variable enables data record compression between the server and clients.

Value

One of the following values:

1 = Compression is requested.

0 = Compression is not requested. (default)

Discussion

SCSCOMPR compresses blanks, nulls, zeros, and repeating characters. Compression can significantly improve the performance of read, write, and store operations on low-speed or busy networks, especially WANs. If you do not use SCSCOMPR, Synergy/DE xfServer will not compress transferred data records.

SCSCOMPR can be set on the server, on the client, or both. The system-specific sections below describe the various ways to set it and how the setting locations interact on each operating system.

To compress data sent to and from all clients, set SCSCOMPR to 1 on the server. Or, to compress data sent to and from individual clients, set SCSCOMPR to 1 on those clients only (and not on the server). To turn compression off, set SCSCOMPR to 0 (or don’t set it at all) on both the client and the server. Setting SCSCOMPR to 0 on the client does not turn off compression if it’s requested on the server.

If you use SETLOG with SCSCOMPR, only the current thread and newly created threads are affected. Prior threads are not changed. SETLOG can be used to change the SCSCOMPR value only on the client; once rsynd has started, SETLOG will not change the compression value on the server.

Windows

On Windows, SCSCOMPR can be set in the registry on the server or in the environment on the client. On a Windows server, use the Synergy Configuration Program to set SCSCOMPR as follows:

From the xfServer/xfServerPlus tab, click the Add xfServer Service button, or select a service from the list of services and click the Modify Service button. The xfServer Information dialog box is displayed.

Select the Compress data packets check box. This sets SCSCOMPR in the registry under HKEY_LOCAL_MACHINE\SOFTWARE\Synergex\Synergy xfServer\service_name\Default (for a specific instance of xfServer) or HKEY_LOCAL_MACHINE\SOFTWARE\Synergex\Synergy xfServer\Default (if you selected the <Default> entry).

Unix

On Unix, SCSCOMPR can be set in the /etc/synrc file or a client’s .synrc file on the server, or in the environment on the client. Setting SCSCOMPR to 0 in the .synrc file in the home directory of the client’s account on the server will override the setting in the master /etc/synrc file, and no compression request will be made to that client from the server. This is a way of setting compression for individual clients from the server. To turn compression completely off, set SCSCOMPR to 0 (or don’t set it at all) in all server setting locations (/etc/synrc and .synrc for each client), as well as in the client’s local environment.

OpenVMS

On OpenVMS, SCSCOMPR can be set in the SERVER_INIT.COM file, the DBLDIR:SYNRC.COM file, or a client SYNRC.COM file. Setting SCSCOMPR to 0 in the SYNRC.COM file in the home directory of the client’s account on the server will override the setting in the master SERVER_INIT.COM and DBLDIR:SYNRC.COM files, and no compression request will be made to that client from the server. This is a way of setting compression for individual clients from the server. To turn compression completely off, set SCSCOMPR to 0 (or don’t set it at all) in all server setting locations (SERVER_INIT.COM, DBLDIR:SYNRC.COM, and SYNRC.COM for each client), as well as in the client’s local environment.

Setting location

See the Discussion above.

Used by

Runtime, xfServer