Analyze logs and metrics with diagnostics settings

This article shows you how to analyze diagnostics data in Azure Spring Apps.

Using the diagnostics functionality of Azure Spring Apps, you can analyze logs and metrics with any of the following services:

• Use Azure Log Analytics. There's a delay when exporting logs to Log Analytics.
• Save logs to a storage account for auditing or manual inspection. You can specify the retention time (in days).
• Stream logs to your event hub for ingestion by a third-party service or custom analytics solution.

Choose the log category and metric category you want to monitor.

Logs

Log	Description
ApplicationConsole	Console log of all customer applications.
SystemLogs	The available LogType values are ConfigServer(Basic/Standard only), ServiceRegistry(all plans)
IngressLogs	Ingress logs of all customer's applications, only access logs.
BuildLogs	Build logs of all customer's applications for each build stage.

Metrics

For a complete list of metrics, see the User metrics options section of Metrics for Azure Spring Apps.

To get started, enable one of these services to receive the data. To learn about configuring Log Analytics, see Get started with Log Analytics in Azure Monitor.

Configure diagnostics settings

1. In the Azure portal, go to your Azure Spring Apps instance.

2. Select diagnostics settings option, and then select Add diagnostics setting.

3. Enter a name for the setting, and then choose where you want to send the logs. You can select any combination of the following options:

   • Archive to a storage account
   • Stream to an event hub
   • Send to Log Analytics
   • Send to partner solution

4. Choose which log category and metric category you want to monitor, and then specify the retention time (in days). The retention time applies only to the storage account.

5. Select Save.

View the logs and metrics

There are various methods to view logs and metrics as described under the following headings.

Use the Logs pane

1. In the Azure portal, go to your Azure Spring Apps instance.

2. To open the Log Search pane, select Logs.

3. In the Tables search box, use one of the following queries:

   • To view logs, enter a query such as the following example:

     AppPlatformLogsforSpring
     | limit 50
     

   • To view metrics, enter a query such as the following example:

     AzureMetrics
     | limit 50
     

4. To view the search result, select Run.

Use Log Analytics

1. In the Azure portal, in the left pane, select Log Analytics.

2. Select the Log Analytics workspace that you chose when you added your diagnostics settings.

3. To open the Log Search pane, select Logs.

4. In the Tables search box, use one of the following queries:

   • To view logs, enter a query such as the following example:

     AppPlatformLogsforSpring
     | limit 50
     

   • To view metrics, enter a query such as the following example:

   AzureMetrics
   | limit 50
   

5. To view the search result, select Run.

6. You can search the logs of the specific application or instance by setting a filter condition, as shown in the following example:

   AppPlatformLogsforSpring
   | where ServiceName == "YourServiceName" and AppName == "YourAppName" and InstanceName == "YourInstanceName"
   | limit 50
   

   Note

   == is case sensitive, but =~ is not.

To learn more about the query language that's used in Log Analytics, see Azure Monitor log queries. To query all your Log Analytics logs from a centralized client, check out Azure Data Explorer.

Use your storage account

1. In the Azure portal, find Storage accounts in left navigation panel or search box.
2. Select the storage account that you chose when you added your diagnostics settings.
3. To open the Blob Container pane, select Blobs.
4. To review application logs, search for a container called insights-logs-applicationconsole.
5. To review application metrics, search for a container called insights-metrics-pt1m.

To learn more about sending diagnostics information to a storage account, see Store and view diagnostics data in Azure Storage.

Use your event hub

1. In the Azure portal, find Event Hubs in left navigation panel or search box.

2. Search for and select the event hub that you chose when you added your diagnostics settings.

3. To open the Event Hub List pane, select Event Hubs.

4. To review application logs, search for an event hub called insights-logs-applicationconsole.

5. To review application metrics, search for an event hub called insights-metrics-pt1m.

To learn more about sending diagnostics information to an event hub, see Streaming Azure Diagnostics data in the hot path by using Event Hubs.

Analyze the logs

Azure Log Analytics is running with a Kusto engine so you can query your logs for analysis. For a quick introduction to querying logs by using Kusto, review the Log Analytics tutorial.

Application logs provide critical information and verbose logs about your application's health, performance, and more. In the next sections are some simple queries to help you understand your application's current and past states.

Show application logs from Azure Spring Apps

To review a list of application logs from Azure Spring Apps, sorted by time with the most recent logs shown first, run the following query:

AppPlatformLogsforSpring
| project TimeGenerated , ServiceName , AppName , InstanceName , Log
| sort by TimeGenerated desc

Show logs entries containing errors or exceptions

To review unsorted log entries that mention an error or exception, run the following query:

AppPlatformLogsforSpring
| project TimeGenerated , ServiceName , AppName , InstanceName , Log
| where Log contains "error" or Log contains "exception"

Use this query to find errors, or modify the query terms to find specific error codes or exceptions.

Show the number of errors and exceptions reported by your application over the last hour

To create a pie chart that displays the number of errors and exceptions logged by your application in the last hour, run the following query:

AppPlatformLogsforSpring
| where TimeGenerated > ago(1h)
| where Log contains "error" or Log contains "exception"
| summarize count_per_app = count() by AppName
| sort by count_per_app desc
| render piechart

Show ingress log entries containing a specific host

To review log entries generated by a specific host, run the following query:

AppPlatformIngressLogs
| where TimeGenerated > ago(1h) and Host == "ingress-asc.test.microservices.azure.cn"
| project TimeGenerated, RemoteIP, Host, Request, Status, BodyBytesSent, RequestTime, ReqId, RequestHeaders
| sort by TimeGenerated

Use this query to find response Status, RequestTime, and other properties of this specific host's ingress logs.

Show ingress log entries for a specific requestId

To review log entries for a specific requestId value <request_ID>, run the following query:

AppPlatformIngressLogs
| where TimeGenerated > ago(1h) and ReqId == "<request_ID>"
| project TimeGenerated, RemoteIP, Host, Request, Status, BodyBytesSent, RequestTime, ReqId, RequestHeaders
| sort by TimeGenerated

Show build log entries for a specific app

To review log entries for a specific app during the build process, run the following query:

AppPlatformBuildLogs
| where TimeGenerated > ago(1h) and PodName contains "<app-name>"
| sort by TimeGenerated

Show build log entries for a specific app in a specific build stage

To review log entries for a specific app in a specific build stage, run the following query. Replace the <app-name> placeholder with your application name. Replace the <build-stage> placeholder with one of the following values, which represent the stages of the build process: prepare, detect, restore, analyze, build, export, or completion.

AppPlatformBuildLogs
| where TimeGenerated > ago(1h) and PodName contains "<app-name>" and ContainerName == "<build-stage>"
| sort by TimeGenerated

Learn more about querying application logs

Azure Monitor provides extensive support for querying application logs by using Log Analytics. To learn more about this service, see Get started with log queries in Azure Monitor. For more information about building queries to analyze your application logs, see Overview of log queries in Azure Monitor.

Convenient entry points in Azure portal

Use following steps to navigate to the Log Analytics pane with predefined queries:

1. Go to the Overview page for your Azure Spring Apps service instance and then select Apps in the navigation pane.

2. Find your target app and then select the context menu.

3. In the pop-up context menu, select View logs.

   

   This action navigates you to the Log Analytics pane with predefined queries.

There are other entry points to view logs. You can also find the View logs button for managed components such as Build Service and Service Registry.

Frequently asked questions (FAQ)

How do I convert multi-line Java stack traces into a single line?

There's a workaround to convert your multi-line stack traces into a single line. You can modify the Java log output to reformat stack trace messages, replacing newline characters with a token. If you use Java Logback library, you can reformat stack trace messages by adding %replace(%ex){'[\r\n]+', '\\n'}%nopex as follows:

<configuration>
    <appender name="CONSOLE" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>
                level: %level, message: "%logger{36}: %msg", exceptions: "%replace(%ex){'[\r\n]+', '\\n'}%nopex"%n
            </pattern>
        </encoder>
    </appender>
    <root level="INFO">
        <appender-ref ref="CONSOLE"/>
    </root>
</configuration>

You can then replace the token with newline characters in Log Analytics, as shown in the following example:

AppPlatformLogsforSpring
| extend Log = array_strcat(split(Log, '\\n'), '\n')

You might be able to use the same strategy for other Java log libraries.

Next steps

• Quickstart: Deploy your first Spring Boot app in Azure Spring Apps