System Requirements

Supported Operating Systems

Supported for production use of Fusion services

Operating system:

  • Windows Server 2008 R2, 2012 and 2012 R2 (x64 only) (see note below)

  • Linux 64-bit (x86_64/amd64 only) with 2.6 or later kernel (see note below)


  • Oracle JRE or JDK 1.8 or later, 64-bit (x64 only)

  • OpenJDK JRE or JDK 1.8 or later, 64-bit (x64/x86_64 only)

Window Server 2008 R2 must have the Microsoft Visual C++ 2008 package installed. Later versions of Windows must have the Microsoft Visual C++ 2010 SP1 package installed.
RedHat based Linux, including CentOS, must be 6.6.x or later or else the bugfix must have been applied. This fix remediates a RedHat bug that will cause Fusion to hang. See for more information.

Also supported for trial and development use of Fusion services

Operating system:

  • Windows 7, 8, and 8.1 64-bit (x64 only)

  • Mac OS X 10.8, 10.9, 10.10

We do not support running Fusion on any 32-bit JVM or operating system.


Fusion is a Java-based application, and thus requires a pre-installed JDK.

Fusion runs on JDK 1.8.

Fusion’s Javascript pipeline stages are application-specific custom JavaScript programs. The JavaScript is compiled by the JDK using the "Nashorn" JavaScript engine the first time that the pipeline is run.

Fusion scripts execute both the java and javac commands, which are usually aliases for the current Java installation. To check which version of Java will be invoked, run the following commands from a shell or terminal window:

java -version
javac -version
echo $JAVA_HOME     // *nix
echo %JAVA_HOME%   // windows

Hardware Requirements

Fusion hardware requirements depend greatly on use case, index size (number of documents), QPS (queries per second) and other factors.

Here are some general recommendations for different Fusion deployments:

Deployment type Memory CPU


8 GB

4 cores

Small Production

32 GB

4 cores

Large Production*

64+ GB

8+ cores

* Large production environments are likely to be made up of multiple servers with these specs.

Fusion components can run on different servers. Different Fusion components require different amounts of resources. Below are the minimum recommended memory requirements; consult Lucidworks for specific recommendations tailored to your unique use case, data load, and production needs.

Fusion component Minimum RAM


2 GB

API service

512 MB

Fusion UI

256 MB


2 GB

Spark master

512 MB

Spark worker

1 GB

Supported Solr Versions and Solr Cluster Requirements

Fusion includes an embedded instance of Solr; see the release history to find out which version is included in each Fusion release. However, you may use Fusion with an external Solr cluster or server. Solr 4.10 and higher are supported.

It is strongly recommended that you use Network Time Protocal (NTP) on a SolrCloud cluster to ensure that nodes use synchronised time. While it is not strictly required, reasoning about log contents and database entries becomes impossible without it. Information and instructions on how to install and run NTP are available at

Recommended HTTP Clients

The Fusion API can be accessed from any HTTP client, and allows you to build user interfaces and applications that work with any browser. However, the Fusion Administration UI, Dashboards, and built-in Search UI are supported only with:

  • Chrome latest version

  • Firefox latest version and latest ESR

  • Internet Explorer 11