wsrep_max_ws_rows confusion

Good day,
Hoping someone can confirm/clear this,

We've just been experiencing node crashes on our xtradb pxc cluster, v.5.6.22-72.0-56-log.
We've had a set of inserts that have grown to a point that caused the nodes to crash.

I tried to chunk the queries which started to help get the tables built, but then it would fail when i created indexes on the complete table.

So after much pain found this variable, wsrep_max_ws_rows, and increased it which appears to have solved the issue.

The documentation is a little vague about this wsrep_max_ws_rows and doesn't fully explain what it relates to, is it the number of rows that are being replicated at one point? also it says that it isn't used in 5.6, but i have tested and it is working.

IF someone has knowledge on this just to clear it up.

Many Thanks

Dan