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 4.3+ 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 5.2.x and 6.x

Operating Systems

Dremio supports the following distributions and versions of Linux:

  • RHEL and CentOS 6.7+, 7.3+, and 8.3 (RPM and tarball)
  • SLES 12 SP2+ (tarball)
  • Ubuntu 14.04+ (tarball)
  • Debian 7+ (tarball)

Java Development Kit

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

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:

$ java -version

You can download the latest version of Java SE from the Oracle website.


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 basedon the Dremio service enabled on the node.

Dremio Node Role Hardware Required
Master-Coordinator 8 CPU cores recommended
16GB RAM recommended
Executor 4 CPU core minimum (16 cores recommended)
16GB RAM minimum (128GB recommended)

Note: Even if you have a machine with 64GB of RAM, only 16GB 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).


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.


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.


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, 64GB), increase Dremio’s default settings for either the direct memory RAM setting or the HEAP setting. A recommended HEAP value is 8GB.

    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).

Warning: 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