Overview

To support developers in analyzing lambdas as they work, we support logging functions. This feature gives you the ability to add logs to your lambdas, in order to monitor the execution & behaviour of your function.

These logs will be stored after every lambda invocation (except manual invocations) for 30 days. You are able to view these logs at Investigate Function Logs. How to log is described in the next chapter below.

Logging Function behavior

The different log-levels are: debug, info, warn and error. All functions take a string as a log message and multiple instances of the extra parameter. These extra parameters are JavaScript objects, providing further insights about the runtime execution. An example for a function which is logged can be found in the LivePerson Functions Templates (at "Logging Template").

The template for the logging functions is as follows:

console.<info/debug/warn/error>(<message> [, extra])

Example code for logging a function:

function lambda(input, callback) {
	console.debug('This is a simple debug message', {
		'bugs': 'none!'
	});

	console.info('Informing you about important news', new Date(), Number.MAX_SAFE_INTEGER);

	try {
		console.warn('Starting a non-existent function');
		nonExistentFunction();
	} catch (e) {
		console.error('You cannot call what you did not create');
	}

	callback(null, 'Function has finished...');
}

After deployment, you should be able to manually invoke your lambda and see the logs written in the Logs section.

Be aware that logs written during manual test invocations will not be written into the storage. Logs with a Debug level will only be shown on manual test invocations and not written into the storage.

Accessing Logs Storage

LivePerson Functions allows developers to investigate lambda logs.

Logs of a certain function can be accessed during development & deployment via the button on the right side. Moreover, our left-hand sidebar allows to also directly navigate to the Investigate Function Logs screen.

When navigating to the Investigate Function Logs screen from a selected function, the search parameters should be pre-defined. In case the left-hand sidebar is used, the relevant lambda needs to be selected from the dropdown.

To fine-tune the selected lambda logs, the following search parameters can be adjusted:

1. Function: The lambda the logs should be displayed for
2. Log Levels: The log levels you want to see (selecting no log level will cause all levels to be displayed)
3. Start Date: The timestamp from which the logs will be shown (only the last 30 days can be selected)
4. End Date: The timestamp to which the logs will be shown (must be after Start Date)

After selecting the parameters, a click on the SEARCH button will show you the logs for the parameters set.

Downloading/Exporting Logs

You can download lambda logs in the logging view. Simply select your lambda, the logging levels, and the relevant time span for which you want to download the logs. After confirmation of the action, the logs will be downloaded as a .csv file.

If you require additional logs beyond the limit we recommend reducing the scope of the log levels (e.g. only error logs) or specifying your time range more precisely.