Improved configuration of database system heap memory
Details
| Detail name | Value |
|---|---|
| Changelog Number | 17833 |
| Type | Improvement |
| Status | Resolved |
| Fix Versions | Exasol 8.29.0 |
| Resolution Date | 2024-07-12 |
Background
Exasol database uses heap memory to perform some calculations.
Sometimes Exasol support might ask customers to change the limit of total heap usage from default value to another one. Some examples could be found in article Connection lost after session running out of memory.
Another system setting is amount of huge pages database should be using.
Since Exasol version 8 the amount of huge pages to use by default is calculated by database automatically.
Improvement
A new parameter was added to the database configuration via ConfD job db_configure: max_system_heap_memory.
This takes a memory size in MiB or GiB and should be used instead of manually setting the -maxSystemHeapMemory database parameter, as it ensures that the system knows how much memory should be allocated as huge pages and avoids unintended out-of-memory situations.
Changed behavior
System heap limit should not be set via DB parameter "-maxSystemHeapMemory". Option "max_system_heap_memory" of ConfD job "db_configure" should be used instead.
