Offlinemap tilecount estimation problem using arcgis android sdk 100.6.0

TirdadRahmani

Dear Arcgis Support Team,

 

we are facing a tilecount limit exceeded issue using the android Arcgis sdk (100.6.0) while we try to download an square envelope in which the upper left corner to the down right corner has a geodetic distance of 36 km.

 

The exact error message returned by the estimation  job  is:

 

“Server job has failed. ERROR 001564: Requested tile count(152831) exceeds the maximum allowed number of tiles(150000) to be exported for service World_Imagery:MapServer.”

 

But when we reduce the distance of 36 km to 34 km from the upper left to the down right envelope corner point the returned estimation result has just 8784 tiles.

 

We are at the moment puzzled and cannot find the reason for the drastically increase of number of tiles just by 2 km broader diameter.

 

To reproduce the error you can use the point  (6.74316766 (lat) , -5.01584100 (long)) in the ivory coast  as the center point of the square.

 

We are highly requesting your support in this regard since in the past we have been able to download a square of 150km from the upper left to the down right corner in our android application which is now blocked.

 

Thanks in advance for your support.

 

Best regards,

Tirdad Rahmani

MarkBaird

Making an albeit insignificant change to the size of a tile cache request can easily make a big difference in the number of tiles you are downloading.

If you consider that a tile cache has multiple levels of detail. For each level of detail (LOD) you go down to, there are even more tiles for that level.  To understand how it grows just consider one level of detail.  It is represented by 3 x 3 tiles so that LOD will contain 9 tiles.  If the extent is increased a little around the edge, then it will grow by one tile in each direction.  So this might equate now to 5 x 5 tiles so we have done from 9 tiles to 25 by only making a small increase in cache size.  You then consider that exactly the same happens for each LOD on your cache and you will appreciate how it grows.

Note that the Android SDK doesn't limit the size of a download cache, this is a server side constraint.

Does this help to explain what is happening?