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hostInfo
Returns: A document with information about the underlying system that the mongod
ormongos
runs on. Some of the returned fields are only included on some platforms.You must run the
hostInfo
command, which takes no arguments, against theadmin
database. Consider the following invocations ofhostInfo
:db.hostInfo() db.adminCommand( { "hostInfo" : 1 } ) In
mongosh
you can usedb.hostInfo()
as a helper to accesshostInfo
. The output ofhostInfo
on a Linux system will resemble the following:{ "system" : { "currentTime" : ISODate("<timestamp>"), "hostname" : "<hostname>", "cpuAddrSize" : <number>, "memSizeMB" : <number>, "memLimitMB" : <number>, // Available starting in MongoDB 4.0.9 (and 3.6.13) "numCores" : <number>, "cpuArch" : "<identifier>", "numaEnabled" : <boolean> }, "os" : { "type" : "<string>", "name" : "<string>", "version" : "<string>" }, "extra" : { "versionString" : "<string>", "libcVersion" : "<string>", "kernelVersion" : "<string>", "cpuFrequencyMHz" : "<string>", "cpuFeatures" : "<string>", "pageSize" : <number>, "numPages" : <number>, "maxOpenFiles" : <number> }, "ok" : <return> }
Output![](/zh-cn/docs/v5.2/assets/link.svg)
hostInfo
The document returned by the
hostInfo
.
hostInfo.system
An embedded document providing information about the underlying environment of the system running the
mongod
ormongos
hostInfo.system.hostname
The system name, which should correspond to the output of
hostname -f
on Linux systems.
hostInfo.system.memLimitMB
The memory usage limit in megabytes.
For example, running in a container may impose memory limits that are lower than the total system memory. This memory limit, rather than the total system memory, is used as the maximum RAM available to calculate WiredTiger internal cache.
Available starting in MongoDB 4.0.9 (and 3.6.13)
hostInfo.system.numaEnabled
A boolean value.
false
if NUMA is interleaved (i.e. disabled), otherwisetrue
.
hostInfo.os
An embedded document that contains information about the operating system running the
mongod
andmongos
.
hostInfo.extra
An embedded document with extra information about the operating system and the underlying hardware. The content of the
extra
embedded document depends on the operating system.
hostInfo.extra.cpuString
A string containing a human-readable description of the system's processor.
cpuString
only appears on macOS systems.
hostInfo.extra.versionString
A complete string of the operating system version and identification. On Linux and macOS systems, this contains output similar to
uname -a
.
hostInfo.extra.libcVersion
The release of the system
libc
.libcVersion
only appears on Linux systems.
hostInfo.extra.kernelVersion
The release of the Linux kernel in current use.
kernelVersion
only appears on Linux systems.
hostInfo.extra.alwaysFullSync
alwaysFullSync
only appears on macOS systems.
hostInfo.extra.nfsAsync
nfsAsync
only appears on macOS systems.
hostInfo.extra.cpuFeatures
Reports the processor feature flags. On Linux systems this the same information that
/proc/cpuinfo
includes in theflags
fields.
hostInfo.extra.physicalCores
Reports the number of physical, non-HyperThreading, cores available on the system.
physicalCores
only appears on macOS systems.
hostInfo.extra.numPages
numPages
only appears on Linux systems.
hostInfo.extra.maxOpenFiles
Reports the current system limits on open file handles. See UNIX
ulimit
Settings for more information.maxOpenFiles
only appears on Linux systems.
hostInfo.extra.scheduler
Reports the active I/O scheduler.
scheduler
only appears on OS X systems.