content_image/869031.jpg content_image/869032.jpg
•The mysql  client and the mysqlxtest  test suite client. (Other clients are not supported. They must be invoked from within the network namespace of the server to which they are to connect.) 

## Host System Prerequisites 

•Regular replication. (Group Replication is not supported.) 

The following sections describe how to use network namespaces in MySQL: 

•Host System Prerequisites 

•MySQL Configuration 

•Network Namespace Monitoring 

Prior to using network namespace support in MySQL, these host system prerequisites must be satisifed: 

•The host operating system must support network namespaces. (For example, Linux.) 

•Any network namespace to be used by MySQL must first be created on the host system. 

•Host name resolution must be configured by the system administrator to support network namespaces. 

<img src='content_image/869031.jpg'>

## Note 

A known limitation is that, within MySQL, host name resolution does not work for names specified in network namespace-specific host files. For example, if the address for a host name in the red  namespace is specified in the /etc/netns/ red/hosts  file, binding to the name fails on both the server and client sides. The workaround is to use the IP address rather than the host name. 

•The system administrator must enable the CAP_SYS_ADMIN  operating system privilege for the MySQL binaries that support network namespaces ( mysqld , mysql , mysqlxtest ). 

<img src='content_image/869032.jpg'>

## Important 

Enabling CAP_SYS_ADMIN  is a security sensitive operation because it enables a process to perform other privileged actions in addition to setting namespaces. For a description of its effects, see https://man7.org/linux/man-pages/man7/ capabilities.7.html. 

Because CAP_SYS_ADMIN  must be enabled explicitly by the system administrator, MySQL binaries by default do not have network namespace support enabled. The system administrator should evaluate the security implications of running MySQL processes with CAP_SYS_ADMIN  before enabling it. 

The instructions in the following example set up network namespaces named red  and blue . The names you choose may differ, as may the network addresses and interfaces on your host system. 

Invoke the commands shown here either as the root  operating system user or by prefixing each command with sudo . For example, to invoke the ip  or setcap  command if you are not root , use sudo ip  or sudo setcap . 

To configure network namespaces, use the ip  command. For some operations, the ip  command must execute within a particular namespace (which must already exist). In such cases, begin the command like this: 

