105
Thisperformancetuning-relatedattributeautomaticallysetsthesizeoftheimportcache
(
importCache
)tobeusedduringthecommand-line-basedimportprocessofLDIFfilestothe
database(the
ldif2db
operation).
InDirectoryServer,theimportoperationcanberunasaservertaskorexclusivelyonthe
command-line.Inthetaskmode,theimportoperationrunsasageneralDirectoryServer
operation.The
nsslapd-import-cache-autosize
attributeenablesthe
importCache
tobeset
automaticallytoapredeterminedsizewhentheimportoperationisrunonthecommand-line.
TheattributecanalsobeusedbyDirectoryServerduringthetaskmodeimportforallocatinga
specifiedpercentageoffreememoryfor
importCache
.
Bydefault,the
nsslapd-import-cache-autosize
attributeisenabledandissettoavalueof
-1
.Thisvalueautosizes
importCache
forthe
ldif2db
operationonly,automaticallyallocating
fiftypercent(50%)ofthefreephysicalmemoryfor
importCache
.Thepercentagevalue(50%)is
hardcodedandcannotbechanged.
Settingtheattributevalueto
50
(
nsslapd-import-cache-autosize: 50
)hasthesameeffect
onperformanceduringan
ldif2db
operation.However,suchasettingwillhavethesameeffect
onperformancewhentheimportoperationisrunasaDirectoryServertask.The
-1
value
autosizes
importCache
justforthe
ldif2db
operationandnotforany,includingimport,general
DirectoryServertasks.
NOTE
Thepurposeofa
-1
settingistoenablethe
ldif2db
operationtobenefitfrom
freephysicalmemorybut,atthesametime,notcompeteforvaluablememory
with
entryCache
,whichisusedforgeneraloperationsoftheDirectoryServer.
Settingthe
nsslapd-import-cache-autosize
attributevalueto
0
turnsoffthe
importCache
autosizingfeature-thatis,noautosizingoccursduringeithermodeoftheimportoperation.
Instead,DirectoryServerusestheSection4.1.22,“nsslapd-import-cachesize” attributefor
importcachesize,withadefaultof
20,000,000
.
TherearethreecachesinthecontextofDirectoryServer:
dbCache
,
entryCache
,and
importCache
.
importCache
isonlyusedduringtheimportoperation.The
nsslapd-cache-autosize
attribute,whichisusedforautosizing
entryCache
and
dbCache
,is
usedduringtheDirectoryServeroperationsonlyandnotduringthe
ldif2db
command-line
operation;theattributevalueisthepercentageoffreephysicalmemorytobeallocatedfor
entryCache
and
dbCache
.
Ifboththeautosizingattributes,
nsslapd-cache-autosize
and
nsslapd-import-cache-autosize
,areenabled,ensurethattheirsumislessthan100.
Parameter
Description
EntryDN
cn=config,cn=ldbmdatabase,cn=plugins,
cn=config
DatabaseAttributesundercn=config,
145