This document deals with improving performance for sites utilizing ArcMap Server (ArcIMS 4.0 only). It focuses on changes that can be made using ArcIMS administration tools.
Note: The performance of ArcMap Services also depends on the composition of the map itself. The ArcGIS Desktop help topic "Creating interactive maps" offers advice on optimizing map composition for interactive use (serving on the Web or creating a published map file to be read in ArcReader).
To optimize performance in an ArcMap Server implementation, the following actions are recommended:
1) Activate recycling of the Spatial Servers.
2) Reconfigure Spatial and Virtual Servers so that ArcMap Services run separately from other ArcIMS services and use single instead of multiple instances.
Recycling is essentially the automatic restarting of Spatial Servers at user-configured times. By recycling the Spatial Server, system resources will be refreshed. All services associated with the Spatial Server will be unavailable during the recycling process. This includes all Virtual Servers (FeatureServer, MetadataServer, ImageServer�) associated with the Spatial Server. The recycling option provides a delay parameter so that if more than 1 Spatial Server exists one remains active while the other is recycling. It is recommended that at least 1 additional Spatial Server be available if activating the recycling feature.
Unlike other ArcIMS components, such as standard Image Server, testing has shown that ArcMap Server performance increases with multiple servers each using single instances. Changing the Spatial/Virtual Server associations of the site so that ArcMap Services are handled separately from other ArcIMS services enables the instance value for ArcMap Services to be changed to one without affecting the instance value for other services.
In the following example, the ArcIMS site begins with 1 Image Service, 1 Feature Service, and 1 ArcMap Image Service all running through 1 Spatial Server.
In order to improve ArcIMS stability the recycle feature will be activated. Since recycling when only 1 Spatial Server is used interferes with the availability of the services, additional servers will be created and a recycling delay of 15 minutes will be set.
Also, to improve ArcMap Service performance, the Spatial Servers associated with ArcMap Virtual Servers will be separated from those used by Feature and Image Virtual Servers. These ArcMap only Spatial Servers will have their instance value set at 1. The Spatial Servers associated with the Feature and Image Virtual Servers will remain at the default setting of 2 instances.
Once finished the site will have 4 Spatial Servers - 2 associated with the ArcMap Virtual Server each with a single instance and 2 associated with the Feature and Image Virtual Servers with 2 instances each. These Spatial Servers will be recycled every 12 hours with a 15-minute delay before the next Spatial Server is recycled.
The following actions are performed in this exercise:
- Activate recycling and set its properties.
In this example, periodic recycling will be set to occur every 12 hours with a 15 minute delay.
<a href='http://support.esri.com/en/knowledgebase/techarticles/detail/22949' target='_blank'>How To: Activate recycling for ArcIMS</a>
- Add additional Spatial Servers. An additional 3 Spatial Servers will be added in this demonstration.
<a href='http://support.esri.com/en/knowledgebase/techarticles/detail/22950' target='_blank'>How To: Add additional Spatial Servers</a>
Keep in mind that each additional server will result in additional RAM needed to run the services.
- Reconfigure the Virtual Servers such that ArcMap Virtual Servers are associated with Spatial Servers separate from those utilized by Feature and Image Virtual Servers and revise the instances used by them.
<a href='http://support.esri.com/en/knowledgebase/techarticles/detail/22951' target='_blank'>How To: Associate Virtual Servers with new Spatial Servers: an ArcMap Server example</a>