2.1.x release notes

This series brings the following features and changes. See the releases below for links to the GitHub tagged releases.

Overview

Service Latency Tracking

As services and service mesh functionality has become prominent, we have been looking at ways to make running scalable services on NATS.io a great experience. One area we have been looking at is observability. With publish/subscribe systems, everything is inherently observable, however we realized it was not as simple as it could be. We wanted the ability to transparently add service latency tracking to any given service with no changes to the application. We also realized that global systems, such as those NATS.io can support, needed something more than a single metric. The solution was to allow any sampling rate to be attached to an exported service, with a delivery subject for all collected metrics. We collect metrics that show the requestor’s view of latency, the responder’s view of latency and the NATS subsystem itself, even when requestor and responder are in different parts of the world and connected to different servers in a NATS supercluster.

Monitoring Endpoints Available via System Services

Monitoring endpoints as listed in the table below are accessible as system services using the following subject pattern:

$SYS.REQ.SERVER.<id>.<endpoint-name> (request server monitoring endpoint corresponding to endpoint name.)
$SYS.REQ.SERVER.PING.<endpoint-name> (from all server request server monitoring endpoint corresponding to endpoint name - will return multiple messages)

For more information on monitoring endpoints see NATS Server Configurations System Events.

Addition of `no_auth_user` Configuration

Configuration of no_auth_user allows you to refer to a configured user/account when no credentials are provided.

For more information and example, see Securing NATS

For full release information, see links below;

TLS Configuration for Account Resolver

This release adds the ability to specify TLS configuration for the account resolver.

resolver_tls {
  cert_file: ...
  key_file: ...
  ca_file: ...
}

Additional Trace & Debug Verbosity Options

trace_verbose and command line parameters -VV and -DVV added. See NATS Logging Configuration

Subscription Details in Monitoring Endpoints

We've added the option to include subscription details in monitoring endpoints /routez and /connz. For instance /connz?subs=detail will now return not only the subjects of the subscription, but the queue name (if applicable) and some other details.

Log Rotation

NATS introduces logfile_size_limit allowing auto-rotation of log files when the size is greater than the configured limit set in logfile_size_limit as a number of bytes. You can provide the size with units, such as MB, GB, etc. The backup files will have the same name as the original log file with the suffix .yyyy.mm.dd.hh.mm.ss.micros. For more information see Configuring Logging in the NATS Server Configuration section.

Queue Permissions

Queue Permissions allow you to express authorization for queue groups. As queue groups are integral to implementing horizontally scalable microservices, control of who is allowed to join a specific queue group is important to the overall security model. Original PR - https://github.com/nats-io/nats-server/pull/1143

More information on Queue Permissions can be found in the Developing with NATS section.

Release notes 2.1.0
Full list of Changes 2.0.4...2.1.0