Symptoms
When using the Event Streams UI, the Messages page loads, but then becomes blank when viewing any topic (either real or simulated).
Causes
The vm.max_map_count property on one or more of your nodes is below the required value of 262144. This causes the message indexing capabilities to fail, resulting in this behaviour.
Resolving the problem
Ensure you set the vm.max_map_count property to at least 262144 on all IBM Cloud Private nodes in your cluster (not only the master node). Run the following commands on each node:
sudo sysctl -w vm.max_map_count=262144
echo "vm.max_map_count=262144" | tee -a /etc/sysctl.conf
Important: This property might have already been updated by other workloads to be higher than the minimum required.