topic Re: Cached Image Service behaving dynamically in basemap gallery in ArcGIS JavaScript Maps SDK Questions

Cached Image Service behaving dynamically in basemap gallery

BillDaigle — Wed, 23 Mar 2016 22:22:50 GMT

I am attempting to load a cached Image Service into a basemap gallery. The image service does work, but it is behaving like a dynamic image service, not a cached one. By that, I mean that it is running a export image request each time the map pans instead of fetching the pregenerated tiles.

Here is a link to the service: https://gisservicemt.gov/arcgis/rest/services/MSL/Reference100k_cached/ImageServer

Here is the link to a jsFiddle demonstrating a basemap gallery with one tiled map service and one tiled image service.

https://jsfiddle.net/bdaigle/22Lgp45f/

If you watch the network traffic, you will see that the two basemaps handle the request very differently -- the tiled map service fetches map tiles, whereas the tile image service runs an exportImage task.

The service does behave like a cached service if I explicitly define it as a ArcGISTiledMapServiceLayer and load it to the map manually (without the use of the Basemap Gallery), so I believe this is an issue with the BasemapGallery itself.

I have a couple of ideas for work arounds, but thought I would check with the community before going down that road.

Any ideas???

Re: Cached Image Service behaving dynamically in basemap gallery

RobertScheitlin__GISP — Thu, 24 Mar 2016 12:46:02 GMT

Bill,

Here is thread with info on what I know about this scenario:

https://community.esri.com/thread/172414#comment-588467

Re: Cached Image Service behaving dynamically in basemap gallery

BillDaigle — Thu, 24 Mar 2016 15:10:45 GMT

Thanks for the link Robert. I took a look at the AMD code for the BasemapGallery. It looks like there is no hope for the service getting loaded to the basemap gallery as a tiled layer unless the service has a 'mapName' property. Unfortunately, Image service don't have this property. Instead, they have a 'name' property.

Here is a potential workaround that I have been "fiddling" with. Essentially, it involves loading the Cached image service as a standard ArcGISTiledMapServiceLayer, then using the basemapGallery's selection-change event to add or remove it from the map.

https://jsfiddle.net/bdaigle/22Lgp45f/8/

Re: Cached Image Service behaving dynamically in basemap gallery

RobertScheitlin__GISP — Thu, 24 Mar 2016 15:14:28 GMT

Bill,

That is a good workaround. You might consider calling tech support and requesting an enhancement to the BasemapGallery.

Re: Cached Image Service behaving dynamically in basemap gallery

MichaelVolz — Thu, 24 Mar 2016 15:22:13 GMT

Bill:

Can you provide a screenshot of the difference between the tiled map service fetches and the tile image service that uses an exportImage task? Are you looking at this in the Network tab of F12 Developer Tools in Google Chrome?

Re: Cached Image Service behaving dynamically in basemap gallery

BillDaigle — Thu, 24 Mar 2016 15:39:46 GMT

I'm working in firefox with firebug, but the network tab in Chrome will give you similar results.

Here is what the calls look when the layer is loaded to the basemapGallery.

Here is what they look like when they are loaded as a regular Tiled Layer:

Re: Cached Image Service behaving dynamically in basemap gallery

MichaelVolz — Thu, 24 Mar 2016 16:05:54 GMT

This is supposed to be a tiled mapservice but it looks more like your image service return.

Can you tell me if this returning the correct object for a tiled mapservice?

Re: Cached Image Service behaving dynamically in basemap gallery

BillDaigle — Thu, 24 Mar 2016 16:16:30 GMT

That looks like a dynamic map service request to me as well. Here is how they should behave:

Dynamic map service: When you pan the map, you should see a single map service request for the current map extent
Tile map service: When you pan the map, you should see zero or more tiles fetched for the given extent. If you already have the tiles cached locally, zero tiles will be returned. If not, one or more tiles will get returned.

Re: Cached Image Service behaving dynamically in basemap gallery

MichaelVolz — Thu, 24 Mar 2016 16:21:03 GMT

Based on your network traffic examples I would agree that it is behaving like a dynamic mapservice, but the performance of the imagery in javascript applications and the javascript viewer made me think it was working as expected like a tiled mapservice as the panning and zooming of the imagery was near instantaneous.

Re: Cached Image Service behaving dynamically in basemap gallery

BillDaigle — Tue, 12 Apr 2016 20:13:59 GMT

Robert,

I did end up submitting a ticket with tech support. They referred me to [BUG-000093062: The Basemap Gallery widget sends an export request instead of requesting for tiles when used with a cached image service.], which has been closed as known limitation.

I couldn't seem to the track down the bug. Probably because it has already been closed. Since I have another workaround, I dropped the issue. Best to pick your battles wisely!

Re: Cached Image Service behaving dynamically in basemap gallery

MichaelVolz — Wed, 13 Apr 2016 13:13:02 GMT

So caching an image service to get better service performance and using it in the BaseMap Gallery is really pointless as ArcGIS Server is just serving it out as an image service anyway?

Re: Cached Image Service behaving dynamically in basemap gallery

RobertScheitlin__GISP — Wed, 13 Apr 2016 13:40:12 GMT

Michael,

Only if you are using an ImageServer url. If you are using MapServer url then all if fine.

Re: Cached Image Service behaving dynamically in basemap gallery

MichaelVolz — Wed, 13 Apr 2016 13:51:05 GMT

Robert:

I have an image service that I cached, but the cached image service still appears with an ImageServer url. In order to obtain a MapServer url would I need to add this image service to an mxd and then cache the mapservice created from the mxd?

Would this not be considered a cascading mapservice (as it contains an image service) that ESRI says is not good practice?

Re: Cached Image Service behaving dynamically in basemap gallery

RobertScheitlin__GISP — Wed, 13 Apr 2016 13:57:14 GMT

Michael,

If you are using Image Server than you will not be able to get the advantages of the basemap gallery using the cached image service. But if you are using a normal map server service than the basemap gallery will use the cache.

So caching an image service to get better service performance and using it in the BaseMap Gallery is really pointless as ArcGIS Server is just serving it out as an image service anyway

So yes, caching an Image Server service is pointless.

Re: Cached Image Service behaving dynamically in basemap gallery

Anonymous User — Thu, 04 Aug 2016 15:54:35 GMT

I'm also running into this. I published an ImagerServer service and tiled and it works great.. except then I noticed what you all have, that the Esri Basemap widget incorrectly requests it as dynamic. And that while this has apparently been assigned a Bug, they have determined they will not be fixing this. (I called Support who verified that it will not be fixed)

So the workaround as Robert Scheitlin, GISP has identified is to publish Dynamic and link it to the Cache. I think I have run into another bug. We have 10.2.2 but we have not installed this patch (Yet) ArcGIS 10.2.2 for Server Map Cache Consumption Patch Hm. I am currently still trying to get my dynamic map service to behave and to show tiles, they keep giving a 404. I think it's just a matter of getting some directory pathing and/or permissions set up right and I feel like I"m getting close... Will update here, when done.