Vertices run in abnormal order

[Chen He]

Hi guys

I met a problem when I am running a pig on tez job in local mode.

This scripts have following topology:

v72->v75->v84->v->v85->v93->v104->v106
                                   |                  ^
                                   |_________|

However, when I run it in local mode. It finish v72 then goes to v104.

I carefully compare logs between general mode and local mode. It looks like
v104 task was added to the scheduling queue earlier than v75's task. Then,
it happens.

I checked DAGSchedulerNaturalOrder and VertexImpl but did not find the
reason.

Any suggestion?

Regards!

Chen