The in-memory debug log
Description
The in-memory debug log is a logging queue that is automatically enabled and receives all messages written, irrespective of message policies. It is completely outside the Logging Provider system.
All messages from all runspaces end up in the same in-memory debug log. Writing to that log is a synchronous operation, other than the action of writing to logs through the Logging Provider instances.
Reading the debug log
To read that debug log, you can use the Get-PSFMessage command. It includes a lot of parameters that allow filtering messages flexibly.
This log is designed to be especially useful for debugging during development.
It also allows instant forensics without having to rerun a command/script with -Verbose.
This log is fully file-less and will be lost if the process is closed. For after the fact logging, look for the File System Logging Provider and the general guidance on the debug log.
By default, only the last 1024 messages will be retained.
The Error log
When writing messages it is quite possible to write / pass through error records. These are often of special interest for debugging purposes.
Due to this, the in-memory log has a dedicated logging queue for logged error records. These have a separate retention of (by default) the last 128 errors being retained, irrespective of the number of non-error messages.
Due to that, even a lengthy task that writes a vast amount of messages will not hide the last errors.
To access the error log, use Get-PSFMessage’s -Errors switch parameter.
Clearing the log
You may sometimes want to clear the log between test run, to only have the current entries from the latest run in there.
There is a way to do that easy: Clear-PSFMessage will handle that in one, neat call:
Clear-PSFMessage
No parameters needed.
Configuring the debug log
There are separate configuration settings governing the in-memory debug log. Each of the log queues can be separately enabled/disabled and resized.
Note: The default size was chosen to prevent large amounts of memory being consumed. Keep that concern in mind if you decide to permanently increase the capacity. The exact memory cost per message is hard to gauge, as provided extra data and targeting information can vastly increase individual message’s size.
Configuration Namespace:
PSFramework.Logging
| Name | Default Value | Description |
|---|---|---|
| MaxMessageCount | 1024 | The maximum number of messages that can be maintained in the in-memory message queue. |
| MaxErrorCount | 128 | The maximum number of error records maintained in-memory. |
| MessageLogEnabled | True | Governs, whether a log of recent messages is kept in memory. |
| ErrorLogEnabled | True | Governs, whether a log of recent errors is kept in memory. |
For more details on how to apply these settings, see the documentation on the Configuration Component.