Qlik Replicate on Linux: High System Memory Usage

[john_wang]

When Qlik Replicate runs on a newly provisioned Linux server, the system memory usage is abnormally high and reaches critical thresholds.

Resolution

To resolve the issue, reduce or disable huge page allocation by updating the kernel parameter:
vm.nr_hugepages = 0

To make it persistent across reboots, update /etc/sysctl.conf. Then apply the change by "sudo sysctl -p"

Cause

The issue is related to the Linux kernel parameter vm.nr_hugepages, which defines the number of huge pages (typically 2 MB each) that are pre-allocated in memory.

In this case, the system was configured with:

vm.nr_hugepages = 24629

This reserves approximately 48 GB of memory (2M * 24629) for huge pages, significantly reducing the amount of available memory for other processes. If too many huge pages are reserved, the system may run low on regular memory pages, leading to performance degradation or instability.

Internal Investigation ID(s)

00352619

Environment

• Qlik Replicate, all versions
• Linux Server, all supported versions