Migration of Elasticsearch from version 5.5 to version 6.3

Owned by Team Kolibri (Unlicensed)
Last updated: Nov 09, 2022 by Technische Redaktion
2 min read

Redline 5 uses a new version of Elasticsearch so it is necessary to migrate the metadata index.

An automatic migration of the Elasticsearch metadata index will occur after installation of redline 5 (including installation of Elasticsearch 6.3) and its start. The system will be under high load during the migration of the metadata index, so users of the system will experience a lower perfromance of redline. During the migration only the already migrated data is available for searching. Once the migration is completed, all objects will be searchable and the system load will return to usual values.

Our performance tests on adequately chosen hardware have shown that it is possible to migrate approximately 2.000.000 objects per hour.

Important: In order to sucessfully complete the the migration of Elasticsearch, it is necessary that the system has at least 16GB of RAM, while we recommend 32GB of RAM. Where necessary (depending on number of objects in the system), a separate server shall be provisioned for Elasticsearch.

Installation of Elasticsearch 6.3 

  • If enaio Service-Manager Service is running on the same server as the Elasticsearch, it has to be stopped prior to ES installation.
  • Stop elasticsearch 5.5.
  • Backup elasticsearch 5.5 data.
  • Uninstall elasticsearch 5.5.
  • Install elasticsearch 6.3 according to Installation Guide Version 5.0.

Update procedure 

Once the installation has been completed:

  • Copy the backed up Elasticsearch 5.5 data directory to the Elasticsearch 6.3 data directory.
  • Start elasticsearch 6.3.
  • Start Service-Manager 5.0.
  • After Service-Manager 5.0 is running, the Elasticsearch database will be updated to the new version by the IndexService.
  • If the system contains more than 3 million objects, an adequate timeslot for the update of Elasticsearch shall be chosen, in order to finish the migration without affecting use of system by standard users. 
    Our tests have shown that it is possible to migrate approximately 2.000.000 objects per hour.


In the case that you have to migrate several million objects and you can not have the downtime resulting from the migration – taken into account that newer objects are migrated first and are available as soon as they were processed – then we offer an offline migration tool. With this you can minimize your downtime to a delta-migration period. If you wish more information and/or want to use the tool, please get into contact with our support team (support@optimal-systems.de). We recommend to use the tool only in collaboration with our consulting team.