I have a local issue with my installation. (FATAL: invalid value for parameter)

Console output:

FATAL:  invalid value for parameter "lc_messages": "en_US.UTF-8"
pg_ctl: could not start server
Examine the log output.
Couldn't start the database.
Couldn't install the database service.
  • You need to install locales en_US.UTF8.

I want to deactivate the image storage for an application

This procedure can't be revert !

Run this:

su - ltu
ltud stop collector
ltud stop weki
export MY_APPLICATION_KEY='....................'
dir_to_delete=`psql -p 7791 saas_si -qtc "update application_property set value=false from application where application_property.name='save_ref_image' and application.id_application=application_property.id_application and application.application_key='$MY_APPLICATION_KEY';select sw_conf.value || '/' || client.folder_path || '/' || application_property.value from application, application_property, sw_conf, client where application.id_application = application_property.id_application and client.id_client = application.id_client and sw_conf.name='storage_root_folder_path' and application_key='$MY_APPLICATION_KEY' and application_property.name='folder_path';"`
rm -rf $dir_to_delete/*
ltud start collector
ltud start weki

I want to change my cores configuration


license feature configuration keys role
weki_nb_cores WEKI_NB_CORES * OPENMP_NUM_THREADS number of weki threads
processor_nb_cores PROCESSOR_NB_CORES * OPENMP_NUM_THREADS number of processor threads
kima_nb_cores KIMA_NB_CORES * OPENMP_NUM_THREADS number of launched kima threads
kima_nb_connections WEKI_KIMA_NB_CONNECTIONS maximum number of weki connections on kima
  • Update the configuration file: add the key/value you want to /opt/ltuengine/config/ltuengine.spec


  • Let's take an example:

My license allows me to a kima_nb_cores = 8 and I rarely make simultaneous requests. In this case, I can decide to reduce KIMA_NB_CORES in favor of OPENMP_NUM_THREADS:

"KIMA_NB_CORES": 2,
"OPENMP_NUM_THREADS": 4,


  • Once you updated the spec file, you must re-generate the configuration files to take your changes into account:
su - ltu
ltusaas-generate-config-files -i /opt/ltutengine/config/ltuengine.spec -m all -o /opt/ltu/env/run/cache/config
ltud restart all

Sometimes I can't reach the dispatcher

Please check that your client is not using hostname but ip. If you do a lot of queries, dns can failed to answer.

When I restart the system, add an image is very slow

That's ok, at the start the first indexations load vocabularies for your dna, that's why it takes more time. We do not want to load every vocabularies at the start for performance reasons, but only needed ones.

I have a lot of 3604 errors when I add an image

This is due to your dns resolve, please use ip address instead of hostname for performance reasons.

What are the ports used by LTU Engine Server

LTU Engine server is based on several internal services that communicate together or are opened to external queries.

Ports used for internal communications:

  • LTU Processor admin 7788
  • LTU Processor 7790
  • Postgresql 7791
  • Rabbit MQ 7792
  • LTU Manager 8081
  • LTU Weki 8082
  • LTU License 27000
  • LTU Kima services - from 8090 to 8190

Ports that must be opened for external queries:

  • NGINX redirecting to LTU Processors 7789
  • NGINX redirecting to LTU Wekis 8080
  • LTU Front Office 8888

How to upgrade my license file

If you are using LTU Engine Server then you will have to update your license file every years. When you have download your license file from our DownloadCenter please follow theses steps:

  1. switch to user 'ltu': su - ltu
  2. backup your old license file: cp config/license.lic config/license.old
  3. add new license file: cp /tmp/MY_NEW_LICENSE_FILE config/license.lic
  4. restart the license server: ltud restart license

Everything should then be updated, please proceed to a few queries to test system status.