Could we have a button to reduce the priority of the background task

[ubacher]

V144. When working with IM5 I encounter again and again the situation where it suddenly (i.e. unexpectedly) starts
loading and processing files. This causes 100% CPU usage and makes (my laptop) very sluggish ( a pain to use: unusable).
This then forces me to go and do something else for an undetermined time.

Could we have a button to reduce the priority of the background task so that (I) one could continue working?

A relate request would be to issue a "beep" when background processing (which took longer than x seconds) is finished.
This way I could enjoy my coffee without having to go back and check periodically to see if it is done.

(Maybe some wizard could write a separate program which monitors CPU usage and alarms when it drops to below 50%?)

This is of course only an interim work-around to the current performance problem.  Once the debugging is done and Mario has time
to profile the program( find bottlenecks: speed up) the need will/should disappear.

[Mario]

V144. When working with IM5 I encounter again and again the situation where it suddenly (i.e. unexpectedly) starts

When you encounter this, what did you do before it?
The only background operations IMatch performs (and which should not use up to much CPU time) are calculations of collections and data-driven categories. Or when IMatch has to rescan folders and files because of change events sent by the operating system.

When IMatch has to process data in the background it monitors the user activity. If the user interface is idle for a few seconds, IMatch performs a part of the required background processing, e.g. recalculates one data-driven category or one collection. Naturally, if you are in the collection view and you access outdated collections, IMatch has to calculate them immediately. Or when you are in the category view (or you have the category panel visible) IMatch has to calculate visible data-driven categories (@Keywords!) immediately when you cause changes.

You have several means to control all this, e.g. disabling background data-driven category calculations, disabling or limiting background folder scans (all under Edit > Preferences > Background Processing). IMatch even allows you to restrict the number of processors to use under Edit > Preferences > Application > Batch Processing.

[ubacher]

The frustration has several causes:
1. Lack of understanding why it suddenly does what it does. (And thus how to avoid it if possible).

2. Inability to stop what it does (just have to wait or do something that does not use much cpu).

[Mario]

1. I cannot tell you what IMatch does if you don't tell me what you did before whatever happens.

For example, if you modify files in external applications, IMatch will rescan the files to bring the database back in synch. If you change metadata, IMatch needs to update data-driven categories and collections. If you do...

2. There is no way to stop a data-driven category calculation. Or a collection calculation. These are operations which usually take only a few seconds and run in the background without the user even noticing.

So, again:

What did you do to cause "this"?
What does the Info & Activity Panel  show?
What does the status bar at the bottom of the IMatch window show?
The log file would also be helpful, if you mark the time "it" happens so we can check the corresponding entries.
The log file also contains global performance data (written when you close IMatch) which may pinpoint certain operations which are exceptionally slow on your system.

IMatch does not eat up CPU cycles just for fun, there is always a good reason. There is always room for improvements and every version I ship runs smoother.

[ubacher]

Since the behavior is unexpected it is hard for me to specify what I did previously (except maybe the last few steps).
I will try to watch out for these occurrences and collect log files if possible. 

I was looking for data driven categories and the only ones I have are the standard Imatch Sample Categories.
Since I don't use them I will delete them.

[Mario]

Deleting unneeded data-driven categories is always a good idea. Even if you don't look at them, IMatch will keep them updated and thus consume CPU cycles and database resources.