Slow PDF export - hanging on "VirtualRepository.CreateClone"

Question

I'm exporting pages from a map series to PDF individually (have to move some things around on each layout). Each export is taking 7+ minutes, but usually only takes less than 30 seconds. I opened up Diagnostic Monitor to see what is taking so long, expecting it to be one of the feature services in the map. Instead, almost all of the delay is on a function called "VirtualRepository.CreateClone". Anyone know what this does and why it would be so delayed? I don't recall ever seeing it before. Detail from the log window in Diagnostic Monitor below. Thanks! Finished creating a virtual repository for background processing

TomBole · Answer

Hi @jmaxwell_braun

"Cloning" the map/layout allows the export to run in the background. Without the export running in the background you wouldn't be able to interact with Pro at all during the export time. Usually, copying the data is a fast process and isn't noticed, but in some instances it can take longer.

If you don't want to run your export in the background, you can do it via Python. The export methods and samples can be found here https://pro.arcgis.com/en/pro-app/latest/arcpy/mapping/layout-class.htm. If you export via the python window the data won't be copied, so your export should be faster. However, you won't be able to use ArcGIS Pro while the export is going on.

With version 3.7 we introduced export run modes. The python work-around mentioned above is basically the same as the foreground mode described here.

I know that you are working with 3.6, and the python work around should work with 3.6, but I thought you might be interested in this new option if you upgrade.

Hope this helps,

Tom

Robert LeClair · Answer

VirtualRepository.CreateClone is an internal ArcGIS Pro operation you can see in Diagnostic Monitor when Pro is cloning (copying) the layout/map state into a temporary “virtual” workspace to render/export (for example, to isolate each map series page/export so it can draw consistently). It isn’t a layer/service call itself—more like Pro preparing an internal export “snapshot.”

When it suddenly becomes very slow, it’s usually because something in that export snapshot is expensive to resolve (commonly complex symbology, lots of vector content, or raster content), or you’ve hit a version-specific performance issue.

There was BUG-000167349 for ArcGIS Pro that was found in 3.2.2 but fixed at 3.6 and 3.5.8 versions.

You could try a flattened PDF export to see if that reduces the processing time.

JamieMaxwell · Answer

Thanks for the reply, MichaelVolz. I'm on 3.6.3. I export maps containing rasters multiple times per day using the same raster basemaps as this one without any unusual delays, so it doesn't seem like my issue is related to a general raster slowness bug. I'm planning to update soon, so hopefully that will fix it.