max 2 concurrent gsnap jobs per i3.metal instnace (#1415)
max 2 concurrent gsnap jobs per i3.metal instnace (#1415)

extensive testing shows 2 run at the same speed as 1 because this machine
has 2 numa nodes;  but with 3 we have seen some issues so best not risk
chanzuckerberg/idseq-web,chanzuckerberg/idseq-web,chanzuckerberg/idseq-web,chanzuckerberg/idseq-web,chanzuckerberg/idseq-web