Workflow Runtime Parameters

The workflow engine supports the following runtime parameters for advanced tuning.

Parameters passed as Java arguments

The following parameters control the workflow history and parallelism:

Parameter name	Description	Default value	Allowed values range
EWFHistoryDepth	Controls the depth of the history kept for the individual workflow type (configuration). If a new instance of the workflow type is about to be run, the number of currently saved historical run-informations is checked and if there is no place for the new run-information (that is, the limit is reached), the oldest run-information is removed. This action removes both run-information and instance resources.	15	10 - 10000
EWFThreadSlots	Limits the number of tasks running in parallel per workflow.	3	3 - 30

Parameter name

Description

Default value

Allowed values range

EWFHistoryDepth

Controls the depth of the history kept for the individual workflow type (configuration). If a new instance of the workflow type is about to be run, the number of currently saved historical run-informations is checked and if there is no place for the new run-information (that is, the limit is reached), the oldest run-information is removed.

This action removes both run-information and instance resources.

10 - 10000

EWFThreadSlots

Limits the number of tasks running in parallel per workflow.

3 - 30

The parameters described are Java arguments, so they must be passed in the Java attribute form when starting the workflow engine (or the server when used as a server-embedded module):

-D<attributeName>=<attributeValue>

Example

-DEWFThreadSlots=6

To pass these runtime parameters permanently on the server startup, modify the onlinectl.bat or onlinectl.sh file by adding the following lines:

onlineCtl.bat

set JAVA_OPTS="-D<attributeName>=<attributeValue>"

onlineCtl.sh

export JAVA_OPTS="-D<attributeName>=<attributeValue>"

Parameters passed as environment variables

The following environment variables limit the size of the task.log file that each workflow task writes:

Variable name Description Default value Allowed values range

Variable name	Description	Default value	Allowed values range
`EWF_LOG_LIMIT`	The size of a `task.log` file, in bytes, at which the log is truncated. When the log is truncated, only the most recent messages are kept.	No limit	10000 or higher
`EWF_LOG_KEEP`	The number of bytes from the end of the log that are kept when the log is truncated.	10000, or one tenth of `EWF_LOG_LIMIT` if that is lower	0 to half of `EWF_LOG_LIMIT`

EWF_LOG_LIMIT

The size of a task.log file, in bytes, at which the log is truncated. When the log is truncated, only the most recent messages are kept.

No limit

10000 or higher

EWF_LOG_KEEP

The number of bytes from the end of the log that are kept when the log is truncated.

10000, or one tenth of EWF_LOG_LIMIT if that is lower

0 to half of EWF_LOG_LIMIT

To learn how the limit is applied, see Limit the size of task logs.

Set the variables in the environment of the process that runs the workflows. To set them permanently on the server startup, add the following lines to the onlinectl.bat or onlinectl.sh file:

onlinectl.bat

set EWF_LOG_LIMIT=10000000
set EWF_LOG_KEEP=50000

onlinectl.sh

export EWF_LOG_LIMIT=10000000
export EWF_LOG_KEEP=50000

This example limits each task log to 10 MB and keeps the last 50 KB of messages when the log is truncated.

Was this page useful?