It appears that a regression has been introduced into the ace:progressBar component beginning with ICEfaces 4.0.

When uploading large files, the expected behaviour in the component is as described in the TLD doc:

"...If server push is enabled, then the component will automatically push progress information to the indicator, and once that has been received, the indicator will automatically switch to display the incrementalprogress bar. The progress pushes are rate limited to be no more frequent than once every 2 seconds, and are only sent at 1% progress increments."

However, with 4.0+ showcase, no incremental progress bar appears, regardless of the file size. Only the none-deterministic flashing bar progress indicator is ever displayed.

I also tested using the org.icefaces.lazyPush=false config. parameter to ensure that push was enabled with the same results.