Support is requesting that the default be made to be 64 MB which was the jvm heap default for many versions of
Domino. Support is seeing low memory panics on servers where http private memory is
wasted on the jvm because the servers are not running xpages. This spr is to
track customer reports for support where we have either had to get the hotfix
for 8.5 or have the customer lower using the ini on 8.5.1 or later.

 

From Technote 1431525

Starting with Domino 8.5 release a new ini setting became the
default for
Domino servers running the http task. That setting is
HTTPJVMMAXHEAPSIZE and
the default size was set to 256MB (megabytes). The setting is
specifically
targeting the JVM being used by the HTTP process. The change was
made to
accommodate Xpages which uses the JVM on the server.
Administrators looking  at
the server's notes.ini after an install would see the setting
-

HTTPJVMMaxHeapSize=256M

In 8.5 this was not changeable by the Administrator. This
ability to modify the
size was added to the 8.5.1 version of the product as documented
in TN#1377205
though the default value of 256MB was still the default.

Starting with 8.5.2 the default value will be set to 64MB. The
first time the
server starts up if the HTTPJVMMaxHeapSize is set to 256MB it
will be reset to
64MB. A new setting will be placed in the server's notes.ini
named
HTTPJVMMaxHeapSizeSet=1. This will keep the server from
resetting the HTTP JVM
heap size on subsequent restarts of the server or HTTP task.
Adminstrator's can
use HTTPJVMMaxHeapSize to set any size they wish for the HTTP
processes heap
size and if the ini HTTPJVMMaxHeapSizeSet=1 is present the
server will adhere
to the size set.
This is only done for 32 bit platforms. The default heap size
for 64 bit
operating systems is 1 Gigabyte.

On Iseries the minimum allowable size is 256 MB.

Customers running multiple servers who are not using xpages do
not need to set
the JVMMaxHeapSize to this size, 64mb is enough.