Shared Instances and Feature Access - question on best practice

[tigerwoulds]

Recently joined a new company and need some advice on their setup. Running Enterprise 1091. Currently our Analysts publish all their data as referenced (from SQL Server) with Shared Instances and Feature Access enabled - regardless of whether they will be editing data through the rest service. 

To me this is unnecessary as it adds additional services on our GIS Server. I'm still trying to wrap my head around shared instances though, so my question is: Does having un-needed feature access on 75% of our services negatively impact server performance?

[ZachBodenner]

I'm sure you've come across documentation like this before:

https://www.esri.com/arcgis-blog/products/arcgis-enterprise/administration/shared-instances-arcgis-s...

In my experience, shared instances are super helpful. I still have a few services with dedicated instances (the only the 6-8 most highly used services), and the rest run on shared. Since the published services themselves aren't hanging out waiting to be used, the feature access service being there doesn't seem to be consuming resources unless it's called upon, so having them doesn't negatively impact performance. At least that's my understand though I'm still learning a  lot about server management so someone could come along and correct me if I'm wrong.

[JalesM · Accepted solution]

I think that anytime your service has "less to do" you should see better performance. If Web Map service has more features to load than necessary, it's doing unnecessary work.

The video below has some good information about performance in general. There is some good information about Web Map service tuning around the 30 minute mark:

• https://www.youtube.com/watch?v=jys3PD3tzmY

[TanuHoque]

Feature Access enabled - regardless of whether they will be editing data through the rest service. 

Shared instance or not, I'd not enable Feature Access if there is no need for editing. There are cases when you might want to take advantage of client side drawing or interactivity, you can still add a layer from a map service as a feature layer. As you know for that all you'd need to do is use a URL that ends with /0 e.g. https://sampleserver6.arcgisonline.com/arcgis/rest/services/SampleWorldCities/MapServer/0

[PatOBrien]

Hi @TanuHoque  - in the case where client side drawing or interactivity is required, does the map service derived feature layer method incur a server performance cost equivalent to using an actual Feature Layer (Feature Access derived)?

If it does incur the same performance cost, I believe a Feature Layer (Feature Access derived) would be the simpler option as far as adding the data to a Map goes, ie:

Feature Access derived Feature Layer - you can use the Add Layer button and search portal for the Feature Layer and then add

Map Server derived Feature Layer: you have to know and add the full MapServer/0 layer id rest URL using Add > Web Service method