having moved inititalisation into startService to handle tub init cleanly,
I neglected the up-call to startService, which wound up not starting the
load_monitor.
also I changed the 'running' attribute to 'started' since 'running' is
the name used internally by MultiService itself.
having changed tahoe-stats to not report data series if there was no recent
data recorded for a node, I wound up making it hide the data series. this
change causes it to report all data series for which stats exist in the
'config' phase, so that they show up, but only report actual data if the
stats are recent, so that they show up as missing if the node is not
reporting stats currently
I'm not convinced if this is the best way to do this, but I find it
handy to have a conscise "quick reference" for the webapi operations
which summarize all related I/O.
Another possibility is to reject this patch, but create a separate
"webapi_quickref.html" with a concise table.
The flow control has been de-obfuscated a bit.
Some output changes.
The test framework has quite a few race conditions, but it does a reasonable job of setting up and cleaning up.
this adds an interface, IStatsProducer, defining the get_stats() method
which the stats provider calls upon and registered producer, and made the
register_producer() method check that interface is implemented.
also refine the startup logic, so that the stats provider doesn't try and
connect out to the stats gatherer until after the node declares the tub
'ready'. this is to address an issue whereby providers would attach to
the gatherer without providing a valid furl, and hence the gatherer would
be unable to determine the tubid of the connected client, leading to lost
samples.
if a node fails to report stats, the natural thing to do in re munin is to
supress the data for that data series. the previous tahoe-stats would output
whatever data was present in the stats_gatherer's stats.pickle, regardless of
how old.
this change means that if the gatherer hasn't received data within the last
5 min, then no data is reported to munin for that node.