pixolution flow requires some third party software. Each of the third party software is free to use. Please note that the licenses differs to the pixolution license. Please read and accept the licenses of each required third party software in order to use pixolution flow.

  • Modern GNU/Linux Server operating system (e.g. Ubuntu Server 16.04 LTS)
  • Java Runtime Environment (JRE) version 1.8 or higher (Oracle JRE is recommended)
  • Apache Solr 7.x (The specific version of Solr is defined in the offer. The delivered pixolution_flow3.4.1_solrX.X.X.jar file is only compatible to that particular Solr version.)

pixolution flow is a plug-in for Solr. The plug-in only consists of the file pixolution_flow3.4.1_solrX.X.X.jar and all runtime dependencies are satisfied by Solr itself.

Performance hint

For best performance we strongly recommend to also add the math library jblas-1.2.4.jar to the classpath. This implementation is often up to 10 times faster than the pure java implementation that ships with pixolution flow. You can download jBlas here. For more information refer to Native math backends for faster indexing

Staging system

Use a staging server that is not used in production when installing or updating pixolution flow. Doing so will not affect your production system in case of errors or issues. This staging server must have software installations and configurations equal to the production system (specifically Solr version and configuration).

Only after successfull installation/update/upgrade and testing of pixolution flow you may deploy the installation to your production system. In your staging system you should run function tests, error robustness tests, inter-operability tests, stress tests and speed tests.

Solr requirements


The provided pixolution_flow3.4.1_solrX.X.X.jar is only compatible with a specific version of Solr, because it was built against those binaries. There are two places where you can check which version pixolution flow is compatible to:

  1. The filename itself contains the version of the pixolution plug-in and the Solr version it is compatible with: pixolution_flow[product version]_solr[solr version].jar.
  2. The JAR file contains the file META-INF/MANIFEST.MF which stores the exact version of Solr the provided plug-in is compatible with (see below).

Part of an example MANIFEST.MF indicating the plug-in version (here 3.4.1) and the compatible Solr version (here 7.2.1):

Implementation - Version: 3.4.1
Implementation - Version - Solr - Core: 7.2.1


For Solr specific configurations please refer to its official reference guide in the specific version.

Unique key

pixolution flow requires a configured <uniqueKey> field in the schema. This field is used for identifying specific documents when doing visual search queries like or atomic updates. The <uniqueKey> field type may be a number or a string.

Example schema configuration of the <uniqueKey> field

<fieldType name="long" class="solr.TrieLongField" precisionStep="0"  positionIncrementGap="0"/>
<field name="id" type="long" indexed="true" stored="true" multiValued=" false"/>

Licensed plan

Depending on your purchased license of pixolution flow you might not be able to use all features described in this guide. Functionality that may be restricted includes - but is not limited to - Distributed Search. Please refer to your offer, to get to know your specific license.

If disabled functionality is accessed, pixolution flow will throw a LicenseError. If you wish to extend your license please contact us.

Some features require a specific configuration of Solr. Those requirements are described in this guide for each functionality. If the described functionality requirements are not met, there is no right to use that particular functionality.