Start/notes.ini Parameters/NSF_DbCache_Maxentries

NSF_DbCache_Maxentries

Parameter: NSF_DbCache_Maxentries
Short description: Maximum number of databases the server keeps open simultaneously in the database cache.

Profile

Parameter
NSF_DbCache_Maxentries
Category
Performance / Memory
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
Server document → Performance → "Maximum cached databases"
Possible values
Integer, typically 100 – 5000; minimum 25, maximum ~2000 (platform-dependent per HCL Wiki). Without an explicit entry, the value is derived from NSF_Buffer_Pool_Size / 300 KB (at least 25).

Description

The database cache holds already opened NSFs on the server side, so that on the next access the expensive open operation (including collation, ACL, view index initialization) is omitted. NSF_DbCache_Maxentries sets the limit on how many databases may be in this cache at the same time.
If the value is too small, databases are frequently displaced from the cache and have to be reopened – this costs CPU and I/O. If it is too large, the server can unnecessarily tie up many handles and memory. Per HCL, Domino briefly caches up to 1.5× the configured limit — so a setting of 1500 may temporarily hold up to 2,250 databases at peak.
The parameter corresponds to the "Maximum cached databases" field in the server document; an entry in notes.ini overrides the server document setting.

Example configuration

NSF_DbCache_Maxentries=1500

Notes & pitfalls

  • Values only take effect after server restart.
  • Check current usage with show stat Database.Database.Cache.*, especially Database.Database.Cache.CurrentEntries, Database.Database.Cache.HighWaterMark, and Database.Database.Cache.OvercrowdingRejections.
  • Frequent OvercrowdingRejections indicate the value is too small.
  • Very high values require an appropriately dimensioned NSF buffer pool and sufficient file handles at the operating system level.
  • On mail servers with many small mail files, a higher value pays off; on application servers with few large DBs, a lower value is sufficient.

Sources (HCL Product Documentation)