Start/notes.ini Parameters/DEBUG_HEAPCHECK

DEBUG_HEAPCHECK

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Parameter: DEBUG_HEAPCHECK
Short description: Enables memory heap checks for diagnosing memory errors (buffer overruns, use-after-free, double-free) – with significant performance impact.

Profile

Parameter
DEBUG_HEAPCHECK
Category
Logging / Debug
Component
Server
Available since
9.0.1
Supported versions
9.0.1, 10.0, 11.0, 12.0, 14.0, 14.5, 14.5.1
GUI equivalent
notes.ini only (no GUI)
Possible values
0 = off (default), 1 = on

Description

DEBUG_HEAPCHECK=1 enables additional consistency checks on Domino's internal heap structures. On every memory allocation or release, Domino verifies that surrounding areas are still intact – this exposes classic memory errors such as buffer overruns, use-after-free, or double-free.
Typically enabled only at the direction of HCL Support, when there is a concrete suspicion of memory corruption (sporadic crashes with different stack traces, data corruption with no recognizable pattern).

Example configuration

DEBUG_HEAPCHECK=1

Notes & pitfalls

  • Significant performance impact – enable only temporarily on test or reproduction systems.
  • Takes effect only after a server restart.
  • Entries appear in console.log, NSD files, and possibly in Debug_Outfile.
  • Complementary to DEBUG_THREADID, DEBUG_CAPTURE_TIMEOUT, NSD scripts.
  • For reproducible crashes, hand the output together with NSD to HCL Support.