How To Approximately Calculate Memory Usage of Syslog-ng (4237373)

NOTE - These calculations are an approximation and should not be used for scoping/scaling of an environment. For assistance with proper scoping/scaling of logging please consult with an One Identity sales representative who can assist with engaging Professional Services.

One Identity Professional Services are trained and able to assist with customization, configurations, scoping, and scaling of environments.



To approximately calculate how much memory usage all sources & destinations are using within the Syslog-ng configuration please see the following formula:

((log-msg-size * log-fifo-size) * Number of Sources) + ((qout-size * log-msg-size) * Number of Sources) = memory used by source(s) & destination(s)

The defaults when not specifically set for these options are as follows:

log-msg-size = 65536 (64 KiB)

log-fifo-size = number of sources * log-iw-size

log-iw-size = 100 (messages)

qout-size = 64 (messages)

A configuration with a single source & destination, using the default values, would approximately use the following memory usage:

((log-msg-size * log-fifo-size) * Number of Sources) + ((qout-size * log-msg-size) * Number of Sources)

(65536 * (1 * 100) * 1) + ((64 * 65536) * 1)

10,747,504 bytes or  ~10.75mb of memory usage

A configuration with 4 sources and 2 destinations, using the default values, would approximately use the following memory usage:

((log-msg-size * log-fifo-size) * Number of Sources) + ((qout-size * log-msg-size) * Number of Sources)

(65536 * (4 * 100) * 4) + ((64 * 65536) * 4)

121,634,816 bytes or  ~121.63mb of memory usage