Upgrade to Thredds 4.1 and timeUnitsChange="true" fixed our FMRC problems

[rsignell]

For those of you having issues with the FRMC aggregations under
THREDDS, please try upgrading to latest thredds 4.1 <ftp://
ftp.unidata.ucar.edu/pub/thredds/4.1/thredds.war> and adding
"timeUnitsChange="true" to your aggregation tag for your FMRC (this is
needed, it turns out, not only when time units change, but then the
number of time steps in each file might change. This might happen,
for example, when a forecast run fails before completion, or you
change the length of the forecast. This fixed a long-standing
problem we had for our USGS FMRC here at USGS having a strange first
time stamp, and occasionally "Inconsistent array length read:
1165128303 != 1914731274" errors upon data access via OPeNDAP.

So for our FRMC dataset, my aggregation tag now looks like this:

<aggregation dimName="runtime"
type="forecastModelRunCollection" timeUnitsChange="true"
recheckEvery="10min">

And for what it's worth, here is my "do_upgrade_thredds" script (run
by the user that runs tomcat). Let me know if there is a better/
smarter way.

$more do_upgrade_thredds

../bin/shutdown.sh
mv thredds.war thredds.bak
rm -rf thredds
wget ftp://ftp.unidata.ucar.edu/pub/thredds/4.1/thredds.war
../bin/startup.sh
# wait 15 secs to deploy thredds
sleep 15
# then copy over USGS idenfier image
cp ../content/thredds/*.jpg ./thredds

-Rich
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