rs01:SECONDARY> db.adminCommand({buildInfo: true})
{
        "version" : "3.0.12",
        "gitVersion" : "33934938e0e95d534cebbaff656cde916b9c3573",
        "OpenSSLVersion" : "OpenSSL 1.0.1f 6 Jan 2014",
        "sysInfo" : "Linux ip-10-229-66-2 3.13.0-24-generic #46-Ubuntu SMP Thu Apr 10 19:11:08 UTC 2014 x86_64 BOOST_LIB_VERSION=1_49",
        "versionArray" : [
                3,
                0,
                12,
                0
        ],
        "loaderFlags" : "",
        "compilerFlags" : "-Wnon-virtual-dtor -Woverloaded-virtual -std=c++11 -fno-omit-frame-pointer -fPIC -fno-strict-aliasing -ggdb -pthread -Wall -Wsign-compare -Wno-unknown-pragmas -Winvalid-pch -pipe -Werror -O3 -Wno-unused-local-typedefs -Wno-unused-function -Wno-deprecated-declarations -Wno-unused-but-set-variable -Wno-missing-braces -fno-builtin-memcmp -std=c99",
        "allocator" : "tcmalloc",
        "javascriptEngine" : "V8",
        "bits" : 64,
        "debug" : false,
        "maxBsonObjectSize" : 16777216,
        "ok" : 1
}

rs01:SECONDARY> db.adminCommand({hostInfo: true})
{
        "system" : {
                "currentTime" : ISODate("2016-07-25T08:20:16.321Z"),
                "hostname" : "host4",
                "cpuAddrSize" : 64,
                "memSizeMB" : 122949,
                "numCores" : 16,
                "cpuArch" : "x86_64",
                "numaEnabled" : false
        },
        "os" : {
                "type" : "Linux",
                "name" : "Ubuntu",
                "version" : "14.04"
        },
        "extra" : {
                "versionString" : "Linux version 3.19.0-56-generic (buildd@lgw01-10) (gcc version 4.8.2 (Ubuntu 4.8.2-19ubuntu1) ) #62~14.04.1-Ubuntu SMP Fri Mar 11 11:03:15 UTC 2016",
                "libcVersion" : "2.19",
                "versionSignature" : "Ubuntu 3.19.0-56.62~14.04.1-generic 3.19.8-ckt15",
                "kernelVersion" : "3.19.0-56-generic",
                "cpuFrequencyMHz" : "2500.088",
                "cpuFeatures" : "fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov pat pse36 clflush mmx fxsr sse sse2 ht syscall nx rdtscp lm constant_tsc rep_good nopl xtopology eagerfpu pni pclmulqdq ssse3 cx16 pcid sse4_1 sse4_2 x2apic popcnt tsc_deadline_timer aes xsave avx f16c rdrand hypervisor lahf_lm fsgsbase smep erms xsaveopt",
                "pageSize" : NumberLong(4096),
                "numPages" : 31475169,
                "maxOpenFiles" : 999999
        },
        "ok" : 1
}