ArcGIS Online is a recurring feature in newsfeeds, media sites, and agencies supporting public health and emergency response across the globe. Many authoritative sources and community members share information about breaking news and major events through dashboards, apps and maps. These applications have provided public information to hundreds of millions, probably billions of people worldwide. Individual Dashboards have clocked over 1.5 million views per hour, totaling over five hundred million views. ArcGIS Online is built on reliable, scalable infrastructure that supports a massive amount of web traffic.
This article is a quick outline of best practices which ensure the applications you build for a large audience are using the ArcGIS Online components essential for optimal scalability. Links to more detailed resources are listed at the bottom of this article.
Scalable checklist for web applications hosted on ArcGIS Online:
- •Use Hosted Feature Layer Views in your public applications to make use of the Swap Source feature, ensuring smooth transitions during major data updates
- •Review the ArcGIS Dashboards scalability best practices
- •For all hosted feature layers and hosted feature layer views:
- – Ensure Editing is disabled
– Set cache control with the longest duration you can, to conserve your organization Feature Data Store resources.
By default, this is set to 30 seconds, but if you edit less frequently—set the cache control to a longer setting. - •Do not use dynamic or relative time queries and filters, such as: current time; in the last five minutes; today; yesterday; tomorrow. Instead, use time references stored as attributes in the data.
- Note: the following Web AppBuilder widgets use dynamic extent and are not recommended for high volume publicly shared apps:
Infographic widget; Query widget; Info Summary widget
These settings optimize scalability for your publicly shared items by ensuring all available caching mechanisms are being used, thereby conserving your organization’s underlying infrastructure.
Without these best practices applied, your organization Standard Feature Data Store and even Premium Feature Data Store may need to put some requests into a queue. This will result in end users experiencing delayed responses and if sustained, may cause error responses. If this occurs, logging a Support case and applying the best practices to the publicly shared items will get you back on the right path.
Beyond scalability, consider the following options to optimize display performance:
- Enable Optimize Layer Drawing option on the layer settings page to make quantization and query faster.
- Create an attribute index for any fields being used as a filter. Though a small amount of additional feature data storage is required to store an attribute index, it will increase the speed of your attribute-driven filters. If your organization would prefer a fixed cost for feature data storage instead of using credits, consider Premium Feature Data Store.
A note on Cacheable queries
Hosted feature layers in ArcGIS Online power maps and apps that can be used for sharing information publicly. The applications use feature layer queries to request data that is then visualized (features are drawn and power pop-ups). Often, the same information is requested and displayed by viewers of the application, and response caching can be used to efficiently use the response from a query over and over again until the data updates. As ArcGIS Online is built to show geospatial information, feature tiles are used to ensure that geometry information can also take advantage of response caching, even when extents and scales change when users are interacting with the map. When you follow the quick setup steps in this article, it ensures that your app is sending cacheable queries that can be stored and utilized by CDN, resulting in an app that is scalable and efficient anywhere in the world.
You can find additional details in the blogs linked below:
Scalable hosted feature layers in ArcGIS Online: Tile queries and response caching
This blog article was originally published on March 11, 2020, and has been updated.
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