Benefits of Analyzing ArcGIS Server Log Entries of Level Info
ArcGIS Server's Info Log Level
In previous Community Articles, I've talked about the wealth of information you can obtain by analyzing the ArcGIS Server logs for elapsed time, wait times (e.g., queue times), and instance creation times.
Analyzing these metrics with tools such as System Log Parser, can help you quantify your GIS deployment to understand what resources users are requesting and how long they are waiting to receive response for them. From there you can decided if you need to increase services instances or add more processing capability.
While getting a statistical view on service performance using elapsed time is good (really good), there is another ArcGIS Server log metric that can bring a whole new perspective to this analysis. The metric is the Info Log Level entry.
Now, this entry is not new feature, but in recent ArcGIS Server releases its Log Level has been elevated (to Info). This makes its valuable information more accessible without the performance penalty of levels like Verbose and Debug.
Why Info Is A Great Entry for Analysis
What makes the Info entry great is that it provides a representation of a request's response time! I say "representation" because the time is taken from the point-of-view of the platform (the moment the request entered the framework) as opposed to the requesting client.
This duration includes elapsed time, wait time and creation time into one value!
For example:
From this screenshot, the Info entry (with Log Code 9999), contains a listing of the request's URL (under the Message column) and the response time (under the Time Elapsed column).
With the Url, you get name of the service of requested as well as the function called.
Note: The time of the Info request entry is in milliseconds. ArcGIS Server may list other log entries at the level of Info that do not correspond to a request's response time.
While you can expect to find times for requests for resources like map services and feature services, you'll see also observe entries that go through the framework but do not utilize an ArcSOC service instance in the traditional sense. For example, calls for static files such as rest.js and main.css (as shown in the screenshot).
In addition to those static items, you may also see response time entries for such resources as hosted feature services and vector tile services. These items, if such services exist in your deployment, are a nice bonus! Granted, requests for such items are typically very fast, but by examining Info type entries, analysis can be performed that usually require an access log.
Note: An access log is commonly found with an IIS or Tomcat (e.g., where the ArcGIS Web Adaptor is installed). While perfectly good technologies that efficiently log every request into the system, they might be a component that is not available with your deployment. The ArcGIS Server Info Level log type helps bridge that gap.
Create a System Log Parser Report from Info Log Level Entries
The ability to create a System Log Parser report from the Info Log Level entries can be found from the Analysis Type option, under ArcGIS Server Log Query (File System).
Note: ArcGIS Server's Log Level must be set to at least Info to create a System Log Parser report based on Info entries.
System Log Parser Info Report
The System Log Parser Info report will show response time statistics for services requests as well as other items that go through the ArcGIS Server framework.
Note: The Info entry discussed in this Article highlights the response times that are recorded for many ArcGIS requests. However, the log entry currently does not break down these requests by user. This detail could probably be inferred by using the RequestID attribute and finding a matching User Authentication entry, but that analysis is not covered in this Article or currently by System Log Parser.
In the end, this analysis is all about turning log data into information...with Info log entries, you can have more information about your GIS deployment and services available to you to help make the best decisions possible.
