This error can appear in the search indexing error log if you do not have sufficient ports for the number of search engines running.
Every search indexing environment requires 2*(content set count) free ports for successful indexing. Oracle ATG Web Commerce Search automatically reserves 28 ports per host, but if you have a large number of content sets, that may not be sufficient.
If you encounter this error, increase the number of hosts. You can also increase the available port range on an existing host:
On the Projects tab, go to Projects > Your Project > Environments.
Click the environment name.
Click the host machine name to which you want to add ports.
Click the Show link for Advanced Settings.
In the Port Numbers for Search Engines option, select Range and enter the new range to use.
Click Save.
