WMS server provides incorrect figure in the case of dataset update

[jgrooss]

In the calculations for scientific flight planning, it may happen, that a datafile is updated, having the identical filename, but more timesteps. It seems that the server does not check for the update and returns false figures by not correctly interpolating within the data. After re-starting the user interface and clearing the cache, a correct figure is shown.
It is not clear, whether this is a problem of the user interface or of the server.
wrong figure:

correct figure:

[jgrooss]

In the shown case, the server was not re-started.

[ReimarBauer]

Please retry with emptied cache and afterwards with Cache disabled from the UI.

[jgrooss]

Reproduction of the error as follows:
There are two data sets, 20210501_00_clamsice_forecast.pl.nc.short (5 timesteps) and
20210501_00_clamsice_forecast.pl.nc.long (11 timesteps) including those of the short data set.
The data sets are copied to icg1805:/private.scratch/icg122/mssdata
On the server, also the data set from previous day is present.

1. copy short data set (5 timesteps) to the server
2. start mss user interface
3. untick use cache
4. retrieve one figure (cloud_ice_mixing_ratio, fixed log scale, init 05-01 0:00 UT, valid, 05-03 0:00UT, 300hPa)
   -> correct figure
5. copy large data set to the server (overwriting the short data set)
6. switch to level 250 hPa and retrieve
   -> wrong figure
7. start new top view panel in same session
8. retrieve identical figure
   -> correct figure

[ReimarBauer]

At the time the server gets a new file replacing the old one the client has to refresh getCapabilities. Thats in the example in 4. and 8.

We could think about to request on each retrieve a verification that the "getCapabilities" data of the client is outdated compared to the servers version.

When it is outdated retrieve happens after the update of GetCapabilities.

[ReimarBauer]

This described behaviour is by design.

An optional parameter updatesequence of the WMS standard can be used to enhance this behaviour.

updatesequence

Description: (Optional) The server may include an UpdateSequence value in its service metadata. If present, this value should be increased when changes are made to the Capabilities (e.g. when new maps are added to the service). The client may include this parameter in its GetCapabilities request.