Prerequisites

Prerequisites to check before using Lenses against your Kafka cluster.

Kafka versions

Any version of Apache Kafka (2.0 or newer) on-premise and on-cloud.

Schema Registry

Any version of Confluent Schema Registry (5.5.0 or newer), APICurio (2.0 or newer) and AWS Glue.

JMX connectivity

Connectivity to JMX is optional (not required) but recommended for additional/enhanced monitoring of the Kafka Brokers and Connect Workers. Secure JMX connections are also supported, as well as JOLOKIA and OpenMetrics (MSK).

For more enable JMX for Lenses itself see here.

Hardware & OS

Run on any Linux server (review ulimits or container technology (docker/kubernetes). For RHEL 6.x and CentOS 6.x use docker.

Linux machines typically have a soft limit of 1024 open file descriptors. Check your current limit with the ulimit command:

ulimit -S -n     # soft limit
ulimit -H -n     # hard limit

Increase as a super-user the soft limit to 4096 with:

ulimit -S -n 4096

Use 6GB RAM/4 CPUs and 500MB disk space.

Memory & CPU

This is the default configuration = Request 1 CPU & Memory 3Gi, Limit 2 CPU & Memory 5Gi

Browser

All recent versions of major browsers are fully supported.

APIs and Websockets

Every action in Lenses is backed by an API or websocket, documented at https://api.lenses.io. A Golang client is available and CLI (command line interface).

For websockets you may need to adjust your loadbalancer to allow them. See here.

Lenses state store

Lenses can use an embedded H2 database or a Postgres database. Postgres is not supplied by Lenses.

TLS termination

By default, Lenses does not provide TLS termination but can be enabled via a configuration option. TLS termination is recommended for enhanced security and a prerequisite for integrating with SSO (Single Sign On) via SAML2.0.

TLS termination can be configured directly within Lenses or by using a TLS proxy or load balancer. Refer to the TLS documentation for additional information.