It seems that Vespucci caches also failed responses

[matkoniecz]

Vespucci Version

Vespucci 11.0.0-5

Download source

google play store

Device (Manufacturer and Model)

Xiaomi Redmi 4

Android Version

6.0.1

Behaviour/Symptoms

After period of poor connection and starting to receive good mobile internet tiles are not downloading.

After deleting cache tiles are downloading normally.

Expected Behaviour

Tile are downloading after restoring connection

How to recreate

Crash dump submitted (no or yes + date)

No

Any other potentially relevant information

It may be misinterpretation as flushing cache takes a long time

[simonpoole]

Yes we do cache actual errors (aka that the tile doesn't exist, but iirc only for bing), but not network errors as far as possible. Essentially the tile in question simply gets removed from the queue once the downloader gives up, but depending on what is happening that may take a long time (as long as it is the queue it won't be retried, and in the typical very very slow network situation you might have lots of tile requests pending), Not sure if this is easily fixable.

Have you tried switching to a different layer and then back again? Other potential workaround: zooming in or out will remove all pending requests for other zoom levels (you do have zoom a full level though).

[simonpoole]

Do you see this particularly often with a specific layer?

FYI the (read) timeout is currently 5 seconds which assuming a tile size of 15-20kB should still be doable with a GPRS or GSM connection, you may need to lower the number of download threads from the standard of 4 down to 1 or 2 though. It is naturally clear that a tile per couple of seconds is very very slow (particularly because on current hi-res phones you may need a -lot- of tiles for the whole screen).

The -other- workaround for bad connectivity is to use a mbtiles container holding the tiles.

[matkoniecz]

Do you see this particularly often with a specific layer?

Geoportal (imagery provided by Polish government) (though I use just this layer for 90%+ of time)

[simonpoole]

Closing, don't think there is anything currently actionable here.