Confluent Platform System Requirements

This topic provides the hardware and software requirements for Confluent Platform.

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Hardware

On-Premises

The following table lists machine recommendations are for installing individual Confluent Platform components.

Note that the recommended CPU resource is the same for all platforms. For example, if 12 CPUs is recommended for non-Kubernetes environment, the recommendation for a Kubernetes environment would also be 12 CPU units.

Component Nodes Storage Memory CPU
Control Center-Normal mode 1 300 GB, preferably SSDs 32 GB RAM (JVM default 6 GB) 12 cores or more
Control Center-Reduced infrastructure mode 1 128 GB, preferably SSDs 8 GB RAM (JVM default 4 GB) 4 cores or more
Broker 3
  • 12 X 1 TB disk. RAID 10 is optional
  • Separate OS disks from Apache Kafka® storage
 64 GB RAM Dual 12-core sockets
KRaft controller 3-5, 3 recommended 64 GB SSD 4 GB RAM 4 cores
Connect 2 Storage is only required at installation time. 0.5 - 4 GB heap size depending on connectors Typically not CPU-bound. More cores is better than faster cores.
Replicator- Same as Connect for nodes, storage, memory, and CPU. (See note that follows about AWS.) 2 Storage is only required at installation time. 0.5 - 4 GB heap size More cores is better
ksqlDB - See Capacity planning 2 Use SSD. Sizing depends on the number of concurrent queries and the aggregation performed. Minimum 100 GB for a basic server. 20 GB RAM 4 cores
REST Proxy 2 Storage is only required at installation time. 1 GB overhead plus 64 MB per producer and 16 MB per consumer 16 cores to handle HTTP requests in parallel and background threads for consumers and producers.
Schema Registry 2 Storage is only required at installation time. 1 GB heap size Typically not CPU-bound. More cores is better than faster cores.
ZooKeeper 3-5
  • Transaction log: 512 GB
  • Storage: 2 X 1 TB SATA, RAID 10

Each write to ZooKeeper must be persisted in the transaction log before the client gets an ack.

Using SSD reduces the ZooKeeper write latency.

 4 GB RAM 2-4 cores
  • If you want to use RAID disks, the recommendation is:
    • RAID 1 and RAID 10: Preferred
    • RAID 0: 2nd preferred
    • RAID 5: Not recommended

Note

If deploying Confluent Platform on AWS VMs and running Replicator as a connector, be aware that VMs with burstable CPU types (T2, T3, T3a, and T4g) will not support high throughput streaming workloads. Replicator worker nodes running on these VMs experience throughput degradation due to credits expiring, making these VMs unsuitable for Confluent Platform nodes expected to run at elevated CPU levels for a sustained period of time, and supporting workloads that are above and beyond their baseline resource rates.

Cloud

For information on Confluent Cloud support, see Supported Features for Confluent Cloud.

Software

Operating Systems

It is recommended that you run Confluent Platform across uniform OS, Confluent Platform, and JAVA versions.

Currently, Confluent Platform supports X86 hardware architecture. ARM64 is supported in Confluent Platform 7.6.0 and later.

Operating System 7.6.x 7.5.x 7.4.x 7.3.x 7.2.x 7.1.x 7.0.x 6.2.x 6.1.x
RHEL 9.x yes yes yes no no no no no no
RHEL/CentOS 8.x yes yes yes yes yes yes yes yes yes
RHEL/CentOS 7.x (deprecated *) yes yes yes yes yes yes yes yes yes
Debian 10 (buster) yes yes yes yes yes yes yes no no
Debian 9 (stretch) (deprecated *) yes yes yes yes yes yes yes yes yes
Rocky Linux 9 yes no no no no no no no no
Rocky Linux 8 yes no no no no no no no no
Ubuntu 20.04 LTS (focal) yes yes yes yes yes yes yes no no
Ubuntu 18.04 LTS (bionic) yes yes yes yes yes yes yes yes yes
Ubuntu 16.04 LTS (xenial) (deprecated *) yes yes yes yes yes yes yes yes yes

* Deprecated: Support for these OS versions is deprecated because they have reached their end of life. The OS is currently supported for Confluent Platform 7.6, but this support may be removed in a future release.

SELinux
Confluent Platform is supported on RHEL, CentOS, Debian, Ubuntu, and Rocky Linux Operating Systems. Confluent is not accountable for Security-Enhanced Linux (SELinux) policy development, support, or enforcement. If you experience issues running Confluent Platform with SELinux enabled on a supported Linux Operating System, contact your OS provider for assistance.
Windows

Windows is not currently supported for Confluent Platform.

Windows 8.1 and later, as well as Windows 2016 and later, are supported by the C/C++ and .NET clients.

macOS
macOS 10.14 and later is supported for testing and development purposes only.
File descriptors
For the file descriptor requirement for Kafka, see File Descriptors and mmap.
ulimit

Control Center requires many open RocksDB files. Set the ulimit for the number of open files to a minimum value of 16384 using the ulimit -n command.

For the other Confluent Platform components, specifically Schema Registry and Replicator, you can leave the ulimit as the OS default.

RHEL with TLS

When installing Confluent Platform on RHEL8 with TLS encryption, you must add DH Key Size JVM Parameters for each component. For more information, see Strong crypto defaults in RHEL 8 and deprecation of weak crypto algorithms.

Set the following component-level environment variables to the argument:

  • Control Center: CONTROL_CENTER_OPTS=-Djdk.tls.ephemeralDHKeySize=2048
  • Schema Registry: SCHEMA_REGISTRY_OPTS=-Djdk.tls.ephemeralDHKeySize=2048
  • Kafka, ZooKeeper, and Connect: KAFKA_OPTS=-Djdk.tls.ephemeralDHKeySize=2048
  • REST Proxy: KAFKAREST_OPTS=-Djdk.tls.ephemeralDHKeySize=2048
  • ksqlDB: KSQL_OPTS=-Djdk.tls.ephemeralDHKeySize=2048
atime

The atime mount option impacts performance, because every read operation on a file system causes a write operation.

Confluent recommends disabling the tracking of atime by setting the noatime option when you mount Kafka data disks.

Java

You need to separately install the correct version of Java before you start the Confluent Platform installation process.

The following table lists Java support in Confluent Platform by version. Note the following:

  • You should use the full JDK to help Confluent Support with troubleshooting and to provide better support if you experience issues with Confluent Platform.
  • OpenJDK, Zulu OpenJDK, Eclipse Temurin (formerly known as AdoptOpenJDK), and Oracle are supported with Confluent Platform.
  • Docker images require version 11. For more information, see Docker.
Confluent Platform Recommended Supported
7.6.x 17 17, 11, 8 *
7.5.x 17 17, 11, 8 *
7.4.x 17 17, 11, 8 *
7.3.x 17 17, 11, 8
7.2.x 11 11, 8
7.1 11 or 8 11, 8
7.0 11 or 8 11, 8
6.2 11 or 8 11, 8
6.1 11 or 8 11, 8
6.0 11 or 8 11, 8

* Java 8 is now deprecated in Confluent Platform, and will be removed in a future version.

From a security perspective, you should use the latest released patch version because older versions may have security vulnerabilities.

Java 9 and 10 are not supported in Confluent Platform as those versions are short-term rapid release versions.

For more information about Java versions, see Java Version History.

Docker

Optional: Docker version 1.11 or later running on a supported operating system. This is required if you are installing Confluent Platform by using the Docker images.

Network

Control Center relies heavily on Kafka, so a fast and reliable network is important for performance. Modern datacenter networking speed of 1 GbE, 10 GbE should be sufficient.

Ports

The table below lists the network services and ports exposed as part of Confluent Platform.

All services listed below use the TCP protocol.

All ports listed below are the default ports, and in most cases you can configure each service to listen on a different port of your choice.

Ports that are indicated to be Internal Only need to be accessible by components within Confluent Platform, not by users or clients of the platform.

When deploying Confluent Platform, ensure that your networking rules allow for the required access to the various components and services.

Component and Service Default Port Internal Only?
ZooKeeper    
  • Peer-to-peer communication
 2888 Yes
  • Peer-to-peer communication
 3888 Yes
  • Client access
 2181 No
  • Client access via TLS
 2182 No
  • Jolokia [*]
 7770 No
KRaft Controller    
  • peer-to-peer communication
 9093 Yes
Kafka Broker    
  • Interbroker listener
 9091 Yes
  • External listener
 9092 No
  • Metadata Service (MDS)
 8090 No
  • Confluent Server REST API
 8090 No
  • Jolokia [*]
 7771 No
(Standalone) REST Proxy 8082 No
Confluent Control Center 9021 No
Kafka Connect    
  • REST API
 8083 No
  • Jolokia [*]
 7773 No
ksqlDB Server    
  • REST API
 8088 No
  • Jolokia [*]
 7774 No
Schema Registry    
  • REST API
 8081 No
  • Jolokia [*]
 7772 No

[*] Reserve the Jolokia ports only when you deploy Confluent Platform using Ansible.

Synchronize time

Clock synchronization on each Kafka broker is required to ensure the full system functions correctly. For example, secure network communication with the brokers that rely on TLS certificate verification may fail if clocks are not synchronized. Clock synchronization can be achieved using utilities like ntpd that implement the Network Time Protocol (NTP).