[erlang-questions] mnesia slow startup

[Paul Mineiro]

hello.

we've been scaling our cluster and we're currently at 24 nodes.  lately
we've noticed that when a node crashes (by running out of memory, oops,
software defect), that restarting mnesia on that node takes a while.  by
"restarting that node", btw, i mean getting through things like
mnesia_controller:try_merge_schema/1 .  when we at say 4 nodes we never
really noticed this.

today we literally went to lunch after a node failed and wasn't
(finishing) starting up, figuring a full stomach would lubricate
cognition. we came back and it had resolved itself.  hurray for
laziness!

however there are still some questions:

  * i'm having a hard time getting some visibility into what is causing a
particular schema transaction(s) to be blocked.  any tricks here?

  * is it expected that certain transactional protocols scale badly with
the number of nodes?

any feedback would be appreciated.  thanks!

-- p

In an artificial world, only extremists live naturally.

        -- Paul Graham