Optimize file compression levels‌

Dimensions CM supports compression on file transfers using ZLIB. You can improve performance by modifying the compression levels.

About file compression levels

The following table describes the file compression levels.

Value	Description
0	No compression. Default for binary file formats.
1	Fastest compression speed but lowest compression obtained. Default for text file formats.
2 to 8	For each increase in the value, compression is increased but there is a decrease in compression speed.
9	Highest compression with slowest compression speed. Gives the best network performance but slows down the performance of the machine.

Guidelines for modifying default values:

Resource or file	Compression level
Plenty of CPU and server memory Binary files Multiple smaller packets	Higher level
Text files	Lower level
Files that are already compressed, for example, .jpg, .mpeg, and .zip	No compression

You can set the file compression values using one of the following methods:

In the Administration Console, choose Fast, Normal, or Best.
In the Dimensions CM command-line interface dmcli, specify a numeric value.

This table describes the administrator console and dmcli equivalent values.

Administration Console value	dmcli equivalent value
Fast	1
Normal	6
Best	9

Set compression level in the Administration Console

To set the compression level, you need the following privilege: Administration Privileges > Process Management Manage File Format Definitions.

To set the compression level:

In the Administration Console, select Configuration Object Management > Data format & MIME types.
Select the Formats tab.
Select the appropriate data format and click Edit. The Edit Data Formats dialog box opens.
From the Compression Level list, select the appropriate compression level. Best is not recommended, as it may overload system performance until data transfer is complete.
Click OK.

Set compression level using dmcli

Using the dmcli command-line client, you can specify if files of the associated format should be considered for compression during transfer (reducing bandwidth) and what level of compression to apply.

Use the optional /COMPRESSION_LEVEL=<level> qualifier with the following DMCLI commands:

DDF (Define Data Formats)
SDF (Set Data Format Flags)

To set compression level in dmcli:

As a user with administrator privileges, run dmcli.
Enter commands and level values as appropriate, for example:

SDF TXT /COMPRESSION_LEVEL=<level>

Enable and disable file compression

To enable or disable file compression, set a value for the following symbol in the dm.cfg configuration file:

DM_COMPRESS_FILES_ON_TRANSFER

Follow the steps in Modify server configuration.

Enable file compression: yes
Disable file compression: no

Modify the compression threshold

To change the compression threshold, add the following symbol to the dm.cfg configuration file:

DM_COMPRESSION_MIN_FILELENGTH n

where n is the compression threshold in bytes.