System Requirements

This topic covers system requirements for standalone clusters including general requirements for Hadoop on YARN and MapR on YARN deployments.

Hadoop Distributions

Dremio supports the following Hadoop distributions:

• Apache Hadoop 2.7.2+ and 3+
• Hortonworks HDP 2.6.5 to HDP 3.0.x
• Cloudera CDH 5 and 6
• Cloudera Data Platform 7.1+
• MapR 6.2.0

note

Dremio 23.0.0+ supports only MapR 6.2.0. If you are running MapR 5.2.x or 6.1.x, you must upgrade to MapR 6.2.0 before upgrading to Dremio 23. Dremio releases up to and including 22.x do not support MapR 6.2.0, only MapR 5.2.x and 6.1.x are supported in releases prior to Dremio 23.

JDK: MapR 6.2.0 supports only JDK 11.

Operating Systems

Dremio supports the following distributions and versions of Linux:

• RHEL and CentOS 6.7+ and 7.3+ (RPM and tarball)
• SLES 12 SP2+ (tarball)
• Ubuntu 14.04+ (tarball)
• Debian 7+ (tarball)

Java Development Kit

Dremio requires that Java SE 8 (JDK 1.8) or Java SE 11 (JDK 11) be installed. Supported distributions are OpenJDK and Oracle JDK. Other versions are not currently supported.

note

Java SE 11 is supported only with Dremio 20.0 and higher and only with certain deployment models. See the Dremio 20.0 Release Notes for more information.

• OpenJDK downloads can be found here.

• Oracle JDK downloads can be found at JDK 8 and JDK 11.

note

The glibc (GNU C Library) implementation of libc is required for OpenJDK. Alpine Linux may use musl, which requires glibc to be installed.

Dremio utilizes the Java compiler (javac) for runtime code generation. You can check to see if your operating system has Java installed (and which version) with this command:

Check Java version

java -version

Browsers

The Dremio UI works best with the following browsers:

• Google Chrome 54+
• Apple Safari 11+
• Mozilla Firefox 50+
• Microsoft Edge 14+

Server or Instance Hardware

The following hardware are minimum recommendations based on the Dremio service enabled on the node.

Dremio Node Role	Hardware Required
Master-Coordinator	16 CPU cores recommended 32 GB RAM recommended
Executor	4 CPU core minimum (16 cores recommended) 16 GB RAM minimum (128 GB recommended) Note: Even if you have a machine with 64 GB of RAM, only 16 GB is used by default. To change this setting, modify the DREMIO_MAX_DIRECT_MEMORY_SIZE_MB property in the dremio-env file and restart the executor node(s).

Network

There should be a low-latency, high-bandwidth network connection between Dremio and the data sources.

The following ports must be open:

Purpose	Port	From	To
UI (HTTPS)	9047	Corporate network (end users)	Coordinators
Arrow Flight	32010	Corporate network (end users)	Coordinators
ODBC/JDBC clients (e.g., Tableau, Power BI)	31010	Corporate network (end users)	Coordinators
ZooKeeper (internal)	2181	Other Dremio nodes (coordinators and executors)	Coordinators
Inter-node communication	45678	Other Dremio nodes	All Dremio nodes
Conduit	ephemeral	Coordinators and Executors	Coordinators and Executors
Data source reads	Varies	All Dremio nodes	Data source nodes

Configuring the Conduit Port

Dremio uses an ephemeral network port allocated by the operating system for inter-node communication between coordinators and executors. To assign a static port number to the conduit port, configure services.conduit.port in the Dremio configuration file. If TLS is enabled on your deployment, Dremio applies the same configuration to communications using the conduit port. To use a different configuration or to enable TLS for only the new conduit port, specify all values for services.conduit.ssl in dremio.conf.

Web Sockets

Dremio uses Web Sockets. If you encounter the following error message: "Your Internet connection may be offline, or WebSockets to Dremio are being blocked.", ensure that your environment allows WebSocket communication.

Performance

A 10 GbE network is recommended when connecting to large data sources that hold terabytes or petabytes of data.

In particular, for maximum performance, it is recommended to use a 10 GbE network between coordinators and executors, executors and executors, and executors and data sources.

Privileges

To install Dremio, the following access privileges are required:

• ssh and scp access
• root or sudo privileges

Best Practices

• For Unix/Linux operating systems, increase your open file limit for users (this impacts the Dremio processes) to 65536.

• If you have a machine with a large amount of RAM (for example, 64 GB), increase Dremio's default settings for either the direct memory RAM setting or the HEAP setting. A recommended HEAP value is 8 GB.

  To increase Dremio's RAM setting:

  1. In the dremio-env file, modify either the DREMIO_MAX_DIRECT_MEMORY_SIZE_MB or DREMIO_MAX_HEAP_MEMORY_SIZE_MB property. See Configuring Memory for more information.
  2. Restart the executor node(s).

caution

For the DREMIO_MAX_DIRECT_MEMORY_SIZE_MB allocation, be sure to leave at least 1-2 GB of memory for the OS.

• To verify the memory assigned to the nodes (heap and direct), run the following query: SELECT * FROM sys.memory