Table of contents

Preparing the cluster for the Watson Knowledge Catalog service

Before the Watson Knowledge Catalog service can be installed, the OpenShift cluster administrator and system administrator must prepare the Red Hat OpenShift cluster.

As a system administrator, perform these tasks:

As the OpenShift cluster administrator, perform this task:

Increase the maximum open file descriptors for CouchDB

Log in as a system administrator and set the maximum open file descriptor parameter to 66560 on every node in the cluster to optimize the CouchDB microservice. The CouchDB microservice provides search within catalogs.

Edit the /etc/security/limits.conf file on every node in the cluster:

hard    nofile      66560
soft    nofile      66560

Set the virtual memory kernel parameter to support Elasticsearch

If you installed the Watson Studio service and set this parameter, you can skip this task.

Log in as a system administrator and set the virtual memory kernel parameter to 262144 on every node in the cluster to support the Elasicsearch microservice. Elasticsearch helps in checking the health of your clusters and creating data visualizations.

Set the parameter on every node in the cluster:

echo "vm.max_map_count=262144" >> /etc/sysctl.conf ; sysctl -p

If you don’t set the parameter, the Elasticsearch pod fails with the following error message:

ERROR: [1] bootstrap checks failed
[1]: max virtual memory areas vm.max_map_count [65530] is too low, increase to at least [262144]

Set the kernel parameters to support the Db2 pod

You must set the kernel semaphores parameter and increase the maximum size of messages and default maximum size of queues to every node in the cluster.

To set the kernel parameters:

  1. Log in as a system administrator.
  2. Set the kernel semaphores parameter on every node in the cluster:

    echo "kernel.sem = 250 1024000 32 4096" >> /etc/sysctl.conf ; sysctl -p
    
  3. Increase the maximum size of messages and default maximum size of queues to 65536 for worker nodes in the cluster:

    echo "kernel.msgmax = 65536" >> /etc/sysctl.conf ; sysctl -p
    echo "kernel.msgmnb = 65536" >> /etc/sysctl.conf ; sysctl -p
    
  4. Confirm the settings by using:

    ipcs -l
    

    If you don’t set the parameters, the installation of the Watson Knowledge Catalog service fails because the Db2 pod does not start.

Set the timezone for the master node

If you installed the Watson Studio service and set the timezone for the master node, you can skip this task.

If the service will be installed on a remote machine that runs in a different time zone than the master node, the time zone for the master node is overwritten by the time zone for the installer node. This time zone discrepancy results in scheduled jobs that don’t run at the correct time.

If necessary, log in as a system administrator and set the timezone for the master node:

  1. Locate the tz database code format associated with the master node time zone.
  2. If the override.yaml file does not exist, create it.
  3. Add the tz database code value to the override.yaml file. For example, if you’re using the America/Los_Angeles database code, add the following value:
     global:
        masterTimezone: 'America/Los_Angeles'
    
  4. Inform the user who is installing the service to include the --override override.yaml option in the installation command.

Run the cpd adm command for the service

Ensure that the Mac OS or Linux machine where you will run the commands meets the appropriate requirements for your environment. See Setting up your Cloud Pak for Data environment.

Log in to your Red Hat OpenShift cluster as the cluster administrator and run the appropriate admin setup command for the Watson Knowledge Catalog service:

  • Run this command on a cluster that can connect to the internet:
     ./cpd-<Operating_System> adm --repo repo.yaml \
         --assembly wkc \
         --namespace <Project>
         --apply
    

    Replace the following variables:

    Variable Replace with
    <Operating_System> For Linux, specify linux. For MacOS, specify darwin.
    <Project> The project where you will install Watson Knowledge Catalog.


  • Run this command on an air-gapped cluster:
     ./cpd-<Operating_System> adm \
         --assembly wkc \
         --version <Assembly_version> \
         --namespace <Project> \
         --load-from <Image_directory_location> \
         --apply
    

    Replace the following variables:

    Variable Replace with
    <Operating_System> For Linux, specify linux. For MacOS, specify darwin.
    <Assembly_version> The version of the assembly that is specified in the cpd-Operating_System-workspace/assembly/lite/versions.yaml file.
    <Project> The project where you will install Watson Knowledge Catalog.
    <Image_directory_location> The location of the cpd-<Operating_System>-workspace directory.

Next step

Install the service