How to Install MongoDB 3.2 on CentOS 7

[code lang=”shell”]
vim /etc/yum.repos.d/mongodb.repo
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Paste this to the file and save using :wq
[code lang=”shell”]

[MongoDB]
name=MongoDB Repository
baseurl=http://repo.mongodb.org/yum/redhat/$releasever/mongodb-org/3.2/x86_64/
gpgcheck=0
enabled=1
[/code]
Download and install mongodb using yum
[code lang=”shell”]
yum install mongodb-org -y
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Start mongod and configure auto start while system boot
[code lang=”shell”]
/etc/init.d/mongod restart
chkconfig mongod on
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Check all the versions
[code lang=”shell”]
[[email protected] ~]# mongo –version
MongoDB shell version: 3.2.3
[[email protected] ~]# mongod –version
db version v3.2.3
git version: b326ba837cf6f49d65c2f85e1b70f6f31ece7937
OpenSSL version: OpenSSL 1.0.1e-fips 11 Feb 2013
allocator: tcmalloc
modules: none
build environment:
distmod: rhel70
distarch: x86_64
target_arch: x86_64
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Test the connection
[code lang=”shell”]
[[email protected] ~]# mongo
MongoDB shell version: 3.2.3
> use test
switched to db test
> db.test.save( { juzhax: 1 } )
WriteResult({ "nInserted" : 1 })
> db.test.find()
{ "_id" : ObjectId("56d4ac48b376b143e4749229"), "juzhax" : 1 }
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WARNING: /sys/kernel/mm/transparent_hugepage/enabled is ‘always’.

After I install MongoDB 3.2.3 in Centos 7, I received this error when I start mongo in shell.

[code lang=”shell”]
[[email protected] ~]# mongo
MongoDB shell version: 3.2.3
connecting to: test
Server has startup warnings:
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten]
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/enabled is ‘always’.
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten] ** We suggest setting it to ‘never’
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten]
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten] ** WARNING: /sys/kernel/mm/transparent_hugepage/defrag is ‘always’.
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten] ** We suggest setting it to ‘never’
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten]
2016-02-29T14:11:49.308-0500 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 4096 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.
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Solution

Create the init.d script.
Create the following file at /etc/init.d/disable-transparent-hugepages:

[code lang=”shell”]
#!/bin/sh
### BEGIN INIT INFO
# Provides: disable-transparent-hugepages
# Required-Start: $local_fs
# Required-Stop:
# X-Start-Before: mongod mongodb-mms-automation-agent
# Default-Start: 2 3 4 5
# Default-Stop: 0 1 6
# Short-Description: Disable Linux transparent huge pages
# Description: Disable Linux transparent huge pages, to improve
# database performance.
### END INIT INFO

case $1 in
start)
if [ -d /sys/kernel/mm/transparent_hugepage ]; then
thp_path=/sys/kernel/mm/transparent_hugepage
elif [ -d /sys/kernel/mm/redhat_transparent_hugepage ]; then
thp_path=/sys/kernel/mm/redhat_transparent_hugepage
else
return 0
fi

echo ‘never’ > ${thp_path}/enabled
echo ‘never’ > ${thp_path}/defrag

unset thp_path
;;
esac
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Make it executable.
Run the following command to ensure that the init script can be used:

[code lang=”shell”]
sudo chmod 755 /etc/init.d/disable-transparent-hugepages
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[code lang=”shell”]
sudo chkconfig –add disable-transparent-hugepages
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WARNING: Cannot detect if NUMA interleaving is enabled. Failed to probe “/sys/devices/system/node/node1”: Permission denied

[code lang=”shell”]
[[email protected] ~]# mongo
MongoDB shell version: 3.2.3
connecting to: test
Server has startup warnings:
2016-02-29T23:11:36.666+0700 I CONTROL [initandlisten]
2016-02-29T23:11:36.667+0700 I CONTROL [initandlisten] ** WARNING: Cannot detect if NUMA interleaving is enabled. Failed to probe "/sys/devices/system/node/node1": Permission denied
2016-02-29T23:11:36.667+0700 W CONTROL [initandlisten]
2016-02-29T23:11:36.667+0700 W CONTROL [initandlisten] Failed to probe "/sys/kernel/mm/transparent_hugepage": Permission denied
2016-02-29T23:11:36.667+0700 W CONTROL [initandlisten]
2016-02-29T23:11:36.667+0700 W CONTROL [initandlisten] Failed to probe "/sys/kernel/mm/transparent_hugepage": Permission denied
2016-02-29T23:11:36.667+0700 I CONTROL [initandlisten]
2016-02-29T23:11:36.667+0700 I CONTROL [initandlisten] ** WARNING: soft rlimits too low. rlimits set to 4096 processes, 262144 files. Number of processes should be at least 131072 : 0.5 times number of files.
[/code]

Solution

I’m using the OVH kernel, so it is impossible to use with MongoDB, to solve this issue I have to install back the original kernel of the linux, then this error will be gone.

WARNING: soft rlimits too low. rlimits set to 4096 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.

I’ve received this error while starting mongo in shell while installing on
[code lang=”shell”]
[[email protected] ~]# mongod –version
db version v3.2.3
git version: b326ba837cf6f49d65c2f85e1b70f6f31ece7937
OpenSSL version: OpenSSL 1.0.1e-fips 11 Feb 2013
allocator: tcmalloc
modules: none
build environment:
distmod: rhel70
distarch: x86_64
target_arch: x86_64
[[email protected] ~]# mongo –version
MongoDB shell version: 3.2.3
CentOS Linux release 7.2.1511 (Core)
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[code lang=”shell”]
WARNING: soft rlimits too low. rlimits set to 4096 processes, 64000 files. Number of processes should be at least 32000 : 0.5 times number of files.
[/code]

Solution

[code lang=”shell”]
vim /etc/security/limits.d/90-nproc.conf
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Then put in
[code lang=”shell”]
mongod soft nproc 64000
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and
[code lang=”shell”]
reboot
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