Exasol cannot allocate huge pages on some host distributions
Details
| Detail name | Value |
|---|---|
| Changelog Number | 17192 |
| Type | Bug |
| Status | Resolved |
| Affected Versions | |
| Fix Versions | Exasol 8.18.0 |
| Resolution Date | 2023-05-25 |
Description
On RHEL 9, Exasol is unable to allocate huge pages in the default configuration.
However, huge pages are still automatically reserved, which means there is less RAM available for the database.
As a result, you may experience:
- Reduced performance
- System instability due to running out of available memory
Workaround
echo -n 500 >/proc/sys/vm/hugetlb_shm_group
Where 500 is the user id that the database is configured to run as (by default exadefusr / 500)
The workaround has to be executed each time the Exasol service is restarted on a node.
Fix
Huge pages are allocated correctly by default on RHEL 9.
