Start/notes.ini Parameters/HTTPJVMMaxHeapSize

HTTPJVMMaxHeapSize

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Parameter: HTTPJVMMaxHeapSize
Short description: Maximum Java heap size for the HTTP JVM (relevant for XPages, Domino REST API, Java servlets).

Profile

Parameter
HTTPJVMMaxHeapSize
Category
HTTP / Web
Component
Server
Available since
R8
Supported versions
9.0.1, 10.0, 11.0, 12.0, 14.0, 14.5
GUI equivalent
Server document
Possible values
Value with unit, e.g. 512M, 1024M, 2G, 4G

Description

HTTPJVMMaxHeapSize sets the maximum Java heap size for the HTTP JVM. This JVM hosts, among other things, XPages, servlets, OSGi plug-ins, and the Domino REST API. With larger XPages applications or many concurrently active sessions, the default value (256M) is often not sufficient – leading to OutOfMemoryError.

Example configuration

HTTPJVMMaxHeapSize=2G

Notes & pitfalls

  • Specify values with a unit: M for megabytes, G for gigabytes – e.g. 1024M or 2G.
  • Calculate the value in combination with NSF_Buffer_Pool_Size_MB and the OS demand so that the server does not swap.
  • The change only takes effect after a restart of the HTTP task (restart task http).
  • On 32-bit JVMs, the practical maximum is around 1.5 GB; 64-bit easily handles several GB.
  • When OutOfMemoryError becomes frequent, enable and analyze heap dumps instead of just raising the value blindly.