Merge pull request #439 from MikeWasson/mike/93919

Add aria-describedby to images

docs/antipatterns/busy-database/index.md

@@ -239,11 +239,13 @@ The following sections apply these steps to the sample application described ear
 
 The following graph shows the results of running a load test against the sample application, using a step load of up to 50 concurrent users. The volume of requests quickly reaches a limit and stays at that level, while the average response time steadily increases. A logarithmic scale is used for those two metrics.
 
-![Load-test results for performing processing in the database][ProcessingInDatabaseLoadTest]
+<img src="./_images/ProcessingInDatabaseLoadTest.jpg" alt="Load-test results for performing processing in the database" aria-describedby="description-1">
+<p id="description-1" class="visually-hidden">This line graph shows user load, requests per second, and average response time. The graph shows that response time increases as load increases.</p>
 
 The next graph shows CPU utilization and DTUs as a percentage of service quota. DTUs provide a measure of how much processing the database performs. The graph shows that CPU and DTU utilization both quickly reached 100%.
 
-![Azure SQL Database monitor showing the performance of the database while performing processing][ProcessingInDatabaseMonitor]
+<img src="./_images/processingindatabasemonitor.jpg" alt="Azure SQL Database monitor showing the performance of the database while performing processing" aria-describedby="description-2">
+<p id="description-2" class="visually-hidden">This line graph shows CPU percentage and DTU percentage over time. The graph shows that both quickly reach 100%.</p>
 
 ### Examine the work performed by the database
 
@@ -255,11 +257,13 @@ If the database operations are purely data access operations, without a lot of p
 
 The following graph shows a load test using the updated code. Throughput is significantly higher, over 400 requests per second versus 12 earlier. The average response time is also much lower, just above 0.1 seconds compared to over 4 seconds.
 
-![Load-test results for performing processing in the database][ProcessingInClientApplicationLoadTest]
+<img src="./_images/processinginclientapplicationloadtest.jpg" alt="Load-test results for performing processing in the database" aria-describedby="description-3">
+<p id="description-3" class="visually-hidden">This line graph shows user load, requests per second, and average response time. The graph shows that response time remains roughly constant throughout the load test.</p>
 
 CPU and DTU utilization shows that the system took longer to reach saturation, despite the increased throughput.
 
-![Azure SQL Database monitor showing the performance of the database while performing processing in the client application][ProcessingInClientApplicationMonitor]
+<img src="./_images/processinginclientapplicationmonitor.jpg" alt="Azure SQL Database monitor showing the performance of the database while performing processing in the client application" aria-describedby="description-4">
+<p id="description-4" class="visually-hidden">This line graph shows CPU percentage and DTU percentage over time. The graph shows that CPU and DTU take longer to reach 100% than previously.</p>
 
 ## Related resources
 
@@ -268,8 +272,3 @@ CPU and DTU utilization shows that the system took longer to reach saturation, d
 [dtu]: /azure/sql-database/sql-database-service-tiers-dtu
 [ExtraneousFetching]: ../extraneous-fetching/index.md
 [sample-app]: https://github.com/mspnp/performance-optimization/tree/master/BusyDatabase
-
-[ProcessingInDatabaseLoadTest]: ./_images/ProcessingInDatabaseLoadTest.jpg
-[ProcessingInClientApplicationLoadTest]: ./_images/ProcessingInClientApplicationLoadTest.jpg
-[ProcessingInDatabaseMonitor]: ./_images/ProcessingInDatabaseMonitor.jpg
-[ProcessingInClientApplicationMonitor]: ./_images/ProcessingInClientApplicationMonitor.jpg