elastic-apm-http-client - npm Package Versions

Add support for coordinating data flushing in an AWS Lambda environment. The following two API additions are used to ensure that (a) the Elastic Lambda extension is signaled at invocation end per spec and (b) a new intake request is not started when a Lambda function invocation is not active.

• Client#lambdaStart() should be used to indicate when a Lambda function invocation begins.
• Client#flush([opts,] cb) now supports an optional opts.lambdaEnd boolean. Set it to true to indicate this is a flush at the end of a Lambda function invocation.

This is a BREAKING CHANGE, because current versions of elastic-apm-node depend on ^10.4.0. If this were released as another 10.x, then usage of current elastic-apm-node with this version of the client would break behavior in a Lambda environment.

Add the freeSocketTimeout option, with a default of 4000 (ms), and switch from Node.js's core http.Agent to the agentkeepalive package to fix ECONNRESET issues with HTTP Keep-Alive usage talking to APM Server (https://github.com/elastic/apm-agent-nodejs/issues/2594).

Add APM Server version checking to the client. On creation the client will call the APM Server Information API to get the server version and save that.

The new Client#supportsKeepingUnsampledTransaction() boolean method returns true if APM Server is a version that requires unsampled transactions to be sent. This will be used by the APM Agent to drop unsampled transactions for newer APM Servers.

There is a new apmServerVersion: <string> config option to tell the Client to skip fetching the APM Server version and use the given value. This config option is intended mainly for internal test suite usage.

Add the expectExtraMetadata: true configuration option and Client#setExtraMetadata(metadata) method to provide a mechanism for the Node.js APM Agent to pass in metadata asynchronously and be sure that the client will not begin an intake request until that metadata is provided. This is to support passing in AWS Lambda metadata that cannot be gathered until the first Lambda function invocation. (Note: The expectExtraMetadata option cannot be used in combination with cloudMetadataFetcher.)

Use Z_BEST_SPEED for gzip compression per https://github.com/elastic/apm/blob/main/specs/agents/transport.md#compression

1. client.flush() will initiate a quicker completion of the current intake request.
2. The process 'beforeExit' event is not used to start a graceful shutdown of the client, because the Lambda Runtime sometimes uses 'beforeExit' to handle freezing of the Lambda VM instance. That VM instance is typically unfrozen and used again, for which this Client is still needed.