topic Re: server cache still using source files in ArcGIS Enterprise Questions

server cache still using source files

EricGardecki — Wed, 20 Jan 2016 15:22:47 GMT

I have a few imagery tile caches created based on imagery in either MrSid or Grid format in ArcGIS Server. I'm trying to clear out some hd space and wanted to remove the copy of the imagery that is on that server, or at least move it. However, despite the cache being created, and I assume being all that is used to display the imagery, Server will not allow me to remove the imagery files that were used to create the cache. If I stop the server service and remove the files, no imagery appears anymore in my applications.

1. Why would a cache need the original imagery data when working with a cache? Is there some way to change this?

2. Where is the reference to the original imagery located so I can change it? I would like to move the data to another drive but not have to recreate the caches since it cripples the server during that process.

Thanks!

Re: server cache still using source files

EricGardecki — Thu, 28 Jan 2016 15:01:42 GMT

Just in case this helps others.... The reason the source data was still being used was the cache was set for "update automatically" instead of manually in the settings. Since it is imagery and won't change, I simply changed to manually and I was then able to move the imagery.

Re: server cache still using source files

RebeccaStrauch__GISP — Thu, 28 Jan 2016 16:41:46 GMT

That's a good tip to remember.

just as a side, I tend to always check "manual" since it's much cleaner, in my opinion, if you can control when and where (extent) the cache is being created. In pre-10.2.x I thought this was even more of a necessary need, especially since we have a large (ocean) waterbody within our full extent that never really needed to be cached at detail (data sources weren't of the quality to make a difference). That's just another reason that having "manual" checked might help for others.

..and one more note...in previous versions (can't remember which one), if you created a new service and set up the cache on creating, even if you select "manual", it would switch/default back to automatic. So what I did was create the service as dynamic...then immediately went back in and set up the cache and "manually" created the cache. You didn't mention what version you were using, so I wanted to mention this in case you are running into that issue.

By the way, since you problem is solved, remember to mark you question as answered.

Re: server cache still using source files

EricGardecki — Fri, 29 Jan 2016 19:37:34 GMT

I have to unmark this as the answer. Although I had this working at one point, it isn't any longer and I can't reproduce it.

So I have no idea why the cache is holding on to the source imagery files but it is and I can't seem to do anything about it.

I'll just find a way to work around it.

Re: server cache still using source files

EricGardecki — Fri, 29 Jan 2016 19:43:39 GMT

Oh and I did see something along the lines of what you said where I set it to manual then it goes right back to automatic. It just seems to be a visual bug though since if you republish the service it shows as manual there as expected.

But if you believe that is what the issue is here then I'm not sure what you are suggesting the solution is.

Re: server cache still using source files

RebeccaStrauch__GISP — Sat, 30 Jan 2016 06:13:24 GMT

Eric, when you say you are removing the original images, you aren't messing with the cache folders under arcgisserver directory, are you? Also, I don't see anyplace that you've mention the version you are using. my suggestions might vary depending on the version.

Have you already checked to make sure that the cache is completely built? If not, and you go to a location/scale there is no cache, and you have crate cache in demand, it will try to go back to the original imagery.

Also, depending on where/how you are using the service and cache will make a difference, for example, ArcMap will interpolate at scales in between the cache scales, but if you specify scales in a web app that are different then the cache scale, it may not interpolate and may not show any image if it cant find the original source.

So, a few more details on how you are using the cache, and exactly the situation when you do not have imagery....if/when you move the source files...would be helpful.

Re: server cache still using source files

EricGardecki — Mon, 01 Feb 2016 13:21:39 GMT

No I'm not touching the cache. I mean the files that were used to create the cache.

I'm on 10.3.1

The caches are 100% and have been in place for months.

I'm using the service in a flex application. I assume that between scales you are just seeing the imagery at a lesser resolution otherwise what's the point of the cache? Are you saying that between scales there is some further action being taken? I hadn't looked for the imagery at any scale other than the default map extent but that may not equal the highest cache level.

Meaning, I shut down the services (there was a lock), moved the source imagery, refreshed my app after restarting services, and the imagery was gone. So the simpler question is, why is there a lock?

Thanks!

Re: server cache still using source files

RebeccaStrauch__GISP — Mon, 01 Feb 2016 16:18:34 GMT

To answer "why is there a lock"....sometimes these are remnants of when a cache built crashed, or if the service went down what something/someone was attached to the service. If the service is down, I think it is safe to delete them. (but I would move them first, as a test).

Since Robert Scheitlin, GISP was/still-is the flex app expert, I tagged him in case he can chime in on how flex handles caches. I have a couple flex apps still, but it's been a while since I messed with them.

Re: server cache still using source files

RobertScheitlin__GISP — Mon, 01 Feb 2016 16:41:26 GMT

Flex will force the map to display at the Levels of Display (LODs) that the map service was cached at, and will not allow for displaying at scales in between LODs. JS and Flex are similar in this manner where SilverLight allowed you to set the map scale to any desired scale and would just zoom the cache tile to fit the desired scale.

Re: server cache still using source files

EricGardecki — Mon, 01 Feb 2016 16:42:54 GMT

I did some further testing, at least with 1 of my imagery caches. I removed the source imagery and restarted the service and it works fine in ArcMap but not in my flex app. There is no imagery shown at all in the latter but I get no error either. ( I can't zoom to a particular scale)

Re: server cache still using source files

EricGardecki — Mon, 01 Feb 2016 16:47:57 GMT

My caches are basemaps and I can zoom in/out at will - it is not tied to the LODs (otherwise I wouldn't be using caches at all because we work at small scales).

http://map.exetertownship.com

Re: server cache still using source files

RobertScheitlin__GISP — Mon, 01 Feb 2016 16:51:09 GMT

Eric,

And you are sure that your Flex App is using a ArcGISTiledMapServiceLayer that points to the cached map service?

Re: server cache still using source files

EricGardecki — Mon, 01 Feb 2016 17:05:48 GMT

hmm...now that you ask, I have them set as type="dynamic"....I believe I had to do that in order to avoid the issue of only being able to zoom to the available LODs. It's been quite awhile since I set that up so I'm not positive that is why I did that.

So would dynamic be the reason for the lock?

Re: server cache still using source files

RobertScheitlin__GISP — Mon, 01 Feb 2016 17:19:19 GMT

Eric,

By looking at your config.xml you are not using any layer types but dynamic so your cached layers are not actually being used at all. You are bypassing the caching because you have them as type="dynamic".

Re: server cache still using source files

RebeccaStrauch__GISP — Mon, 01 Feb 2016 17:27:52 GMT

My guess is yes, that could be the reason for the lock since as dynamic, it will be trying to access the service and original data sources.

So, it sounds like it is more of a Flex web app issue, and not an issues with ArcGIS Server. I would mark Robert's answer as correct, and maybe try Moving Content to ArcGIS Viewer for Flex ...but then again, I just tagged it so the thread will be discoverable over there too.

Re: server cache still using source files

EricGardecki — Mon, 01 Feb 2016 18:50:41 GMT

so I changed a layer to "tiled" and it doesn't display at all now, no errors. Not sure what I'm missing here.

Re: server cache still using source files

RobertScheitlin__GISP — Mon, 01 Feb 2016 19:01:06 GMT

Eric,

Did you change one of the layers that was using a Map Service that is cached? The thing to understand is that a Map Service that is cached can be used as dynamic or tiled if you choose tiled then it will use the LODs and tiles that the cached service provides and if you set the type to dynamic it will use the same map service but ignore the tiles and request the server provide a image each time a request is made instead of using the cached image tiles. But the opposite is not true if you have a Map Service that has not cached tiles and you set the layer type to tiled then the layer will just fail to draw on the map.

Re: server cache still using source files

EricGardecki — Mon, 01 Feb 2016 19:13:38 GMT

The services are cached and status is 100% tile creation.

from the map service properties in ArcMap:

from server manager:

I don't know what I'm missing

Re: server cache still using source files

RebeccaStrauch__GISP — Mon, 01 Feb 2016 19:22:16 GMT

I'm not sure, but could "allow clients to cache tiles locally" cause the locking?

Also, are you zooming in only to those scales (LODs) you have cached? or are you trying to zoom to additional scales. Per Robert's comments.

Flex will force the map to display at the Levels of Display (LODs) that the map service was cached at, and will not allow for displaying at scales in between LODs.

Re: server cache still using source files

RobertScheitlin__GISP — Mon, 01 Feb 2016 19:26:54 GMT

Eric,

Because you are using type dynamic on all your base maps the caches are not being used and the fact that you have a 102100 and 2272 wkids in your base maps do not matter. But when you switch to tiled then all wkids have to be identical.