Hello,
I am seeing some problems when running very long requests from a single
location using NCSS.
My dataset has 40 years of monthly files with hourly data (from ERA5). The
dataset dimensions are:
time 355728 X latitude 176 X longitude 172
When requesting one year of data for four variables for a single location (NCSS
Grids As Point Data) it takes 5.2 seconds. I would expect that two years would
take 10.4s and so forth, but I am seeing a non-linear growth in the time. I run
a few tests using wget to retrieve the data and got:
query (years) real time (s) expected time (s)
1 5.2 5.2
2 13 10.4
3 23 15.6
4 37 20.8
5 53 26
6 70 31.2
7 91 36.4
8 117 41.6
9 142 46.8
10 175 52
The query for the whole dataset (40 years), expected to take 208s (5.2 x 40)
took 53 minutes (3180s). Did anyone faced a similar problem? Maybe I need to
make some changes to the cache configuration?
The results are for a dataset aggregated with '<aggregation dimName="time"
type="joinExisting">', but similar results were found for this dataset when
using FMRC (a little slower actually).
The system configuration is:
THREDDS 4.6.14
Apache Tomcat/8.5.45
Linux Kernel 4.15.0-72-generic
Thank you.
Greetings
--
Marcelo Andrioni