Start/notes.ini Parameters/FTG_MAX_MEM_POOL

FTG_MAX_MEM_POOL

Parameter: FTG_MAX_MEM_POOL
Short description: Maximum number of concurrent FT search threads — multiplied by FTG_MB_PER_THREAD this yields the global memory pool limit of the FT engine.

Profile

Parameter
FTG_MAX_MEM_POOL
Category
Performance / Memory
Component
Server
Available since
9.0.1 (older)
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
Integer (concurrent threads) — default 512

Description

FTG_MAX_MEM_POOL defines the maximum number of concurrent FT search threads in the GTR engine (General Text Retrieval). Default is 512. Multiplied by FTG_MB_PER_THREAD (default 1 MB), this yields the global memory pool limit available to all FT searches combined.
The parameter is part of the tuning family from HCL KB0038904 and is used together with FTG_MB_PER_THREAD to cap full-text memory usage globally on a server. FTG_MAX_MB_PER_THREAD, by contrast, defines the individual hard limit per thread, while FTG_CHECK_THREAD_MAX_MEM activates the corresponding monitoring.

Example configuration

Explicitly set the default value:
FTG_MAX_MEM_POOL=512
Reduce global memory pool (smaller servers, many concurrent queries):
FTG_MAX_MEM_POOL=256
FTG_MB_PER_THREAD=2
Larger pool for search-intensive workloads:
FTG_MAX_MEM_POOL=1024
FTG_MB_PER_THREAD=2

Notes & pitfalls

  • Only effective on servers (FT engine).
  • Only effective in combination with FTG_MB_PER_THREAD — the global pool size is the product.
  • Values that are too low can lead to wait times for new full-text searches under load; values that are too high can lead to uncontrolled memory consumption.
  • Companion parameters: FTG_MB_PER_THREAD, FTG_MAX_MB_PER_THREAD, FTG_CHECK_THREAD_MAX_MEM, FTG_USE_SYS_MEMORY.
  • Monitoring: show stat FT.* on the server console.
  • Takes effect after a server restart (classic notes.ini parameter).

Sources (HCL Product Documentation)