Red Hat and CentOS Installation

Couchbase Server supports Red Hat (RHEL) and RHEL-based operating systems such as CentOS.

Before you start with the installation, ensure that dependency checking tool pkgconfig is installed. The Couchbase Server package requires this package to verify certain package dependencies have been met.

Check OpenSSL Dependency

The Couchbase Server RPM performs dependency checks using pkgconfig for RHEL. Verify that pkgconfig is installed, and install it if necessary:

sudo yum install -y pkgconfig

Upon successful installation, the following output appears:

Loaded plugins .... Installed: pkgconfig.x86_64 1:0.21-2.el5 Complete!

Please ensure that you are running OpenSSL v1.0.1g or higher. On Monday, April 7th, 2014, an OpenSSL vulnerability was disclosed which has been called one of the worst security holes in recent internet history. The bug, called the Heartbleed bug, was introduced in OpenSSL version 1.0.1. It has been in the wild since March of 2012 and is patched with OpenSSL version 1.0.1g released on April 7th, 2014. The problem, tagged CVE-2014-0160, is described in detail in this NIST article.

For CentOS systems, you can query the version of the OpenSSL package installed on your system by typing:

 rpm -q -a | grep "openssl"

You should receive output that looks like this:

openssl-1.0.1e-16.el6_5.7.x86_64

If you are on one of the supported distributions, ensure that your OpenSSL version is up-to-date. If your distribution is not supported anymore, it is highly recommended that you transition to a supported operating system due to this bug’s severity.

Installing Using `rpm`

Install Couchbase Server on RHEL using the rpm command-line tool with the downloaded RPM package.

Only 64-bit systems are supported. See Supported Operating Systems for details.

Disable Transparent Huge Pages (THP)

RHEL6 and other newer Linux distributions are known to have Transparent Huge Pages (THP) feature enabled by default. THP can cause issues in database software, including Couchbase Server. THP can cause nodes to lose cluster heartbeats, resulting in erroneous automatic fail overs. Disabling Transparent Huge Pages (THP) prior to installing Couchbase Server is strongly encouraged.

Complete the Installation

You must be logged in as root (superuser) or use the sudo command to complete the installation. Use the following command to install the Couchbase Server package:

rpm --install couchbase-server-version.rpm

where version is the version number of the downloaded package.

After the rpm command completes, the Couchbase Server service starts automatically. It is configured to start automatically under OS runlevels 2, 3, 4, and 5. Refer to the Red Hat RPM documentation for more information about installing packages using RPM.

After installation is completed, the installation process displays a message similar to the following:

    Minimum RAM required : 4 GB
    System RAM configured : 8174464 kilobytes
    Minimum number of processors required :  4 cores
    Number of processors on the system : 4 cores


    Starting couchbase-server[ OK ]

    You have successfully installed Couchbase Server.
    Browse to http://host_name:8091/ to configure your server.
    Refer to http://couchbase.com for additional resources.

    Update your firewall configuration
    to allow connections to the following ports:

    11211, 11210, 11209, 4369, 8091, 8092 and from 21100 to 21299.


    By using this software you agree to the End User License Agreement.
    See /opt/couchbase/LICENSE.txt.

After the installation is completed, use the service command to manage the Couchbase Server service, including checking the current status. Refer to the Ubuntu documentation for instructions.

To perform the initial Couchbase Server setup, open a web browser and access the Couchbase Web Console.

Installing as non-root, non-sudo

Installing on RHEL as a non-root, non-sudo user on a single machine.

A non-sudo, non-root installation still runs Couchbase Server and all Couchbase command-line tools.

After downloading the Couchbase Server RPM, go to the directory where it is located and extract it:
```
rpm2cpio couchbase-server-enterprise_version.rpm | cpio --extract --make-directories --no-absolute-filenames
```
In the directory where the files were extracted, the opt and etc sub-directories are available.
After you extract the Couchbase Server installation files, go to the sub-directory:
```
cd opt/couchbase
```
Run the following script to relocate the Couchbase Server installation to the present working directory (PWD):
```
./bin/install/reloc.sh `pwd`
```
This enables you to continue the installation as a non-root, non-sudo user.

To run the server, use

./bin/couchbase-server \-- -noinput -detached

To stop the server, use
```
./bin/couchbase-server -k
```

Installing using `yum`

This installation uses a package management system.

To install on RHEL/CentOS version 6 or 7 using yum:

Download and install the appropriate meta package from the package download location. This will install the package source and the Couchbase public keys:
```
curl -O http://packages.couchbase.com/releases/couchbase-release/couchbase-release-1.0-5-x86_64.rpm
sudo rpm -i couchbase-release-1.0-5-x86_64.rpm
```

Proceed with installing the actual Couchbase Server package:

sudo yum update

Then:

sudo yum install couchbase-server

Or:

sudo yum install couchbase-server-community

About Max Process Limits

On Red Hat and CentOS systems, it is recommended that you increase the maximum process limits for Couchbase.

To set the process limits, create a .conf file in the /etc/security/limits.d directory (such as 91-couchbase.conf), and add the following values:

couchbase soft nproc 4096
couchbase hard nproc 16384