pt-table-sync failure after 75% of long run

I am working to sync 2 database servers in master-master configuration running Percona Server 5.5.25 over a busy WAN with the pt-table-sync tool (Percona toolkit 2.1.8 ). The servers have 1600 databases with a total size of around 450 GB. But I am getting an error after it has been running for a while and I’m not sure why.

I am running the following command from the slave I’m trying to sync:

The sync ran for 3-4 days, occasionally throwing the error of “”. This error is expected due to a configuration issue I am working with our application developers on.

What doesn’t make sense to me is that 75% or so into the sync run (based on the tool running through the databases alphabetically and the issue starting in the p-named databases), I started getting the following error: “”

I had seen this error before for all tables, and faster, on Percona toolkit 2.1.7. I thought with the upgrade the issue had gone away. Is there a database timeout causing this to occur? I have the timeout set really high in the command line.

Any suggestions on how to resolve this would be appreciated.