A transaction describes an event captured by an Elastic APM agent instrumenting a service. APM agents automatically collect performance metrics on HTTP requests, database queries, and much more.
Selecting a service brings you to the transactions overview.
The transaction duration, transactions per minute, transaction error rate, and time spent by span type charts display information on all transactions associated with the selected service:
- Transaction duration
- Response times for this service, broken down into average, 95th, and 99th percentile. If there’s a weird spike that you’d like to investigate, you can simply zoom in on the graph - this will adjust the specific time range, and all of the data on the page will update accordingly.
- Transactions per minute
Visualize response codes:
4xx, etc., and is useful for determining if you’re serving more of one code than you typically do. Like in the Transaction duration graph, you can zoom in on anomalies to further investigate them.
- Transaction error rate
- Visualize the total number of transactions with errors divided by the total number of transactions. Any unexpected increases, decreases, or irregular patterns can be investigated further with the errors overview.
- Time spent by span type
Visualize where your application is spending most of its time. For example, is your app spending time in external calls, database processing, or application code execution?
The time a transaction took to complete is also recorded and displayed on the chart under the "app" label. "app" indicates that something was happening within the application, but we’re not sure exactly what. This could be a sign that the agent does not have auto-instrumentation for whatever was happening during that time.
It’s important to note that if you have asynchronous spans, the sum of all span times may exceed the duration of the transaction.
The Transactions table displays a list of transaction groups for the selected service. In other words, this view groups all transactions of the same name together, and only displays one entry for each group.
By default, transaction groups are sorted by Impact. Impact helps show the most used and slowest endpoints in your service - in other words, it’s the collective amount of pain a specific endpoint is causing your users. If there’s a particular endpoint you’re worried about, you can click on it to view the transaction details.
If you only see one route in the Transactions table, or if you have transactions named "unknown route", it could be a symptom that the agent either wasn’t installed correctly or doesn’t support your framework.
For further details, including troubleshooting and custom implementation instructions, refer to the documentation for each APM Agent you’ve implemented.
Additional RUM goodies, like core vitals, and visitor breakdown by browser, location, and device, are available in the Observability User Experience tab.
Selecting a transaction group will bring you to the transaction details. This page is visually similar to the transaction overview, but it shows data from all transactions within the selected transaction group.
Up to ten sampled transactions are also displayed. These sampled transactions are based on the bucket selection in the Transactions duration distribution chart. You can update the sampled transactions by selecting a new bucket. The number of requests per bucket is displayed when hovering over the graph, and the selected bucket is highlighted to stand out.
The screenshot below shows a typical distribution, and indicates most of our requests were served quickly—awesome! It’s the requests on the right, the ones taking longer than average, that we probably want to focus on.
When you select a bucket, you’re presented with up to ten trace samples. Each sample has a trace timeline waterfall that shows how a typical request in that bucket executed. This waterfall is useful for understanding the parent/child hierarchy of transactions and spans, and ultimately determining why a request was slow. For large waterfalls, expand problematic transactions and collapse well-performing ones for easier problem isolation and troubleshooting.
More information on timeline waterfalls is available in spans.
For a particular transaction sample, we can get even more information in the metadata tab:
- Labels - Custom labels added by agents
- HTTP request/response information
- Host information
- Container information
- Service - The service/application runtime, agent, name, etc..
- Process - The process id that served up the request.
- Agent information
- User - Requires additional configuration, but allows you to see which user experienced the current transaction.
- Custom - You can configure your agent to add custom contextual information on transactions.
All of this data is stored in documents in Elasticsearch. This means you can select "Actions - View sample document" to see the actual Elasticsearch document under the discover tab.