It's difficult for me to see what Snaps are in use to give an accurate assessment on performance, but if performance continues to be an issue, contact your SnapLogic Customer Success Manager or SnapLogic Support.
One thing to note is that validation only uses a sample of data (50 records by default) so it's possible that any filtering in your pipeline may have removed those 50 records and there was nothing left to work with, which is why it looks like it did not finish.
After looking at your picture (quite difficult), My question is on the left bottom the joins, it seems that they are still waiting for input document but with which snaps are they connected ? Because if the mid right snaps is still waiting for a response from somwhere and that is connected to the other joins snap they are waiting for all inputs until further processing normally. So you need to look that there is not an infinite loop for waiting on each other while the one cannot get started without the other:
If I could see the numbers that connects the dots you can follow the flow and see where it is still processing the documents
Thanks for taking a look. I purposely made it hard to read to not give away any important information, but I acknowledge that it makes it hard to help me.
The Snaps you highlighted are connected.