AWS Lambda log collection

You can collect logs directly from your AWS Lambda functions and send them to Dynatrace for analysis. The solution is an alternative to the CloudWatch log forwarder with benefits in terms of cost and latency, and is also easier to set up, in particular if AWS Lambda tracing is already in place. As part of the OneAgent installation process, this feature provides a streamlined solution for collecting logs from your Lambda functions.

Prerequisites

• Dynatrace version 1.263
• An ActiveGate with the Log analytics collector module enabled. See Log Monitoring API - POST ingest logs.

Deploy

For Python, Node.js, and Java Lambda functions, Dynatrace provides a single Lambda layer that enables both trace and log collection. For .NET, Dynatrace provides a standalone layer that collects only logs.

Usage

After deployment, collected logs for each future function invocation and initialization can be found in the Related logs card on the Lambda function's service page in Dynatrace, and in the Log viewer. You can inspect the log details to find the type of the log under the telemetryevent.type attribute, among other metadata. Note that the content of platform logs will be JSON data, while the content of function logs will be plain text.

Configuration

Log event types

You can configure which log event types are collected. By default, two types of logs are collected: platform events and function logs. For more information about the log event types, see the AWS Lambda Telemetry API documentation.

To configure which types of log event types are collected, you have two options:

1. Set the DT_LOG_COLLECTION_EVENT_TYPES environment variable. The value of this environment variable needs to be a colon-separated list of log event types. For example, to collect only function logs, set the environment variable to function. To collect both platform and function logs, set the environment variable to platform:function (this is the default value).
2. Set the EventTypes property of the LogCollection block in the dtconfig.json configuration file. The value of this property needs to be an array of strings. For example, to collect only function logs, set the property to ["function"]. To collect both platform and function logs, set the property to ["platform", "function"] (this is the default value).

Limitations

• The extension event type currently is not supported: if you try to configure the extension event type, an error is shown and log collection does not start.
• By default, logs collected by the log collector are not associated with traces and are not shown in the trace view in the Logs tab, and will only be shown on the Related logs card or in the Log viewer. However, you may use manual log enrichment in order to connect your function logs to your traces. See AWS Lambda logs in context of traces for language-specific examples of manual log enrichment.
• In the Dynatrace web UI, logs are marked as error logs only if the log message contains the string [error] or [ERROR].
• We do not recommend combining the standalone collector layer with a OneAgent layer. If you want tracing and log collection for your Lambda functions, use the combined Traces and Logs layer instead.
• For Dynatrace Managed, the DT_CONNECTION_BASE_URL environment variable can't be copied from the deployment screen. Instead, a URL of the form https://{activegate-host}:9999/e/{your-environment-id} must be used, where activegate-host needs to be an environment ActiveGate with a (not self-signed) trusted certificate. Refer to Custom SSL certificate for ActiveGate for more details.

Troubleshooting

Dynatrace does not ingest logs (HTTP 429)

If the log exporter prints errors saying that log ingest is disabled or receives an HTTP 429 status code, then you first need to make sure you are using Log Monitoring v2. Once you are, you should then check that your log events ingest limit is sufficient by navigating to Settings > Internal > Indexed Log Storage Settings in your tenant and entering a reasonable value for Maximum ingest of Log Events (100000 is the default).

Debug logging

If other methods of troubleshooting don't resolve your issue, you can enable debug logging of the log collector itself. To do so, set environment variable DT_LOG_COLLECTION_LOG_LEVEL to debug and set DT_LOGGING_DESTINATION to stdout in the Lambda function's configuration. This will cause the log collector to print debug logs to the Lambda function's log stream. You can then view these logs in the CloudWatch console. Note that the collector will not send its own logs to Dynatrace. Also be aware that enabling debug logging should only be used temporarily, as it will generate a large amount of logs in CloudWatch, which may impact the performance of the function.

Alternatively, if you are using dtconfig.json configuration, you can enable debug logging by setting the LogCollection.LogLevel and Logging.Destination properties:

jsoncopydownload
{
  ...other values...
  "Logging": {
    "Destination": "stdout"
  },
  "LogCollection": {
    ...other values...
    "LogLevel": "debug"
  }
}