Start/notes.ini Parameters/FT_Domain_Idxthds

FT_Domain_Idxthds

Parameter: FT_Domain_Idxthds
Short description: Number of indexing threads for Domain Search. Default: 2 threads per CPU. HCL recommendation: maximum 8 threads per server.

Profile

Parameter
FT_Domain_Idxthds
Category
Performance / Memory (Domain Indexer tuning)
Available since
At least 9.0.1 (HCL documentation)
GUI equivalent
notes.ini only (no GUI)
Possible values
Integer 1–8 (HCL recommendation)
Default
2 threads per CPU (e.g. 4 with 2 CPUs)

Description

According to HCL product documentation:
By default, the indexing server uses two indexing threads per CPU, so a server with two CPUs uses four indexing threads when indexing. By adding the variable FT_Domain_Idxthds=n to the NOTES.INI file of the indexing server, you can control the total number of threads used for indexing on that server. For example, by adding FT_Domain_Idxthds=8 to the NOTES.INI file of an indexing server with two CPUs, you change the number of indexing threads to eight.
Note: Do not exceed eight threads per server or you may degrade the performance of the server, even on servers with more than four CPUs.
With FT_Domain_Idxthds, the administrator regulates the total number of indexing threads of the Domain Indexer. Each thread indexes one repository (database/file system) simultaneously. More threads → faster indexing, but slower search responses and higher CPU load; fewer threads → slower index updates, but faster searches.
Important: HCL explicitly warns not to exceed 8 threads per server — even on servers with more than 4 CPUs.

Example configuration

FT_Domain_Idxthds=8

Notes & pitfalls

  • Only for indexing servers (servers running the Domain Indexer task).
  • Maximum per HCL: 8 — above this, performance losses instead of gains are likely.
  • Change requires restart of the Indexer task or the server.
  • Complementary to the indexer frequency (default 60 minutes), which is configured via the Domain Catalog.

Sources (HCL Product Documentation)