Start/notes.ini Parameters/NSF_DbCache_MinEntries

NSF_DbCache_MinEntries

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Parameter: NSF_DbCache_MinEntries
Short description: Minimum number of NSFs the database cache always keeps open – prevents cache flapping under heavily fluctuating load.

Profile

Parameter
NSF_DbCache_MinEntries
Category
Performance / Memory
Component
Server
Available since
10.0
Supported versions
10.0, 11.0, 12.0, 14.0, 14.5, 14.5.1
GUI equivalent
notes.ini only (no GUI)
Possible values
Integer (default 25; typically 25–50 % of NSF_DbCache_Maxentries)

Description

The database cache keeps frequently used NSFs open to save open / close overhead. Under heavily fluctuating load (e.g. quiet at night, busy during the day), the cache can constantly oscillate between “almost empty” and “full” – cache flapping that immediately degrades performance after load peaks. NSF_DbCache_MinEntries sets a lower bound: even during quiet phases at least this many NSFs are kept open, so no warm-up phase is required after a load increase.

Example configuration

NSF_DbCache_MinEntries=200

Notes & pitfalls

  • Always set the value relative to NSF_DbCache_Maxentries (typically 25–50 %).
  • Takes effect after a server restart.
  • Monitor via show stat Database.DbCache* (hits, misses, open count).
  • Min values that are too high keep unnecessarily many NSFs open – watch out for NOTES_MAX_FILEHANDLES and OS limits.