Update guide

Starting from version 12.0, DPI is supported only on CentOS 8.x and veos.

Preparation for update

Make sure that the DPI configuration and dependent services (pcrf, radius) are valid.
Check the currently installed version:
```
yum info fastdpi
```

If CentOS 8.x is used, once switch repositories to vault:

sed -i -e '/^mirrorlist=http:\/\//d' -e 's/^# *baseurl=http:\/\/mirror.centos.org/baseurl=http:\/\/vault.centos.org/' /etc/yum.repos.d/CentOS-*.repo

If there are dependency issues or the update cannot be found, run:
```
yum clean all
```

For virtual machines, old processors (approximately before 2009), and old amd processors (before ryzen):

Before updating, run:

touch /etc/dpi/noprioadj

In this case, DPI will start with a normal (non-realtime) priority, which reduces cpu (sys) load but may slightly increase latency.

Starting with version 14.0, UDR is divided into UDR and SDR. The division occurs automatically when the version is updated.

Installation of a test (beta) version:

yum --enablerepo vasexperts-beta update fastdpi

If the module yaml error occurs during update, update the module:

dnf upgrade libmodulemd

If the SSG (fastdpi) and PCRF (fastpcrf) modules are installed on different physical or virtual servers, two conditions must be met:

Uniform software version:
Ensure that the same versions of the fastdpi and fastpcrf packages are installed on both servers. Version mismatches between SSG and PCRF can lead to errors.
Restart sequence:
Processes must be restarted in the order specified below to restore the connection correctly.
Procedure for a distributed scheme:
1. On the SSG server, stop the DPI service:
```
service fastdpi stop
```
2. On the PCRF server, restart the PCRF service:
```
service fastpcrf restart
```
3. On the SSG server, start the fastdpi service:
```
service fastdpi start
```

This order ensures that all services are started correctly.

After updating or changing the version, be sure to restart DPI:

service fastdpi restart

If PCRF and/or radius are used, they must also be restarted (only with a valid configuration):

service fastpcrf restart
service fdpi_radius restart

Recommended PCRF restart order:

service fastdpi stop
service fastpcrf restart
service fastdpi start

Do not update the linux kernel version and kernel-dependent utilities.

Example rollback to version 14.0:

yum downgrade fastdpi-14.0 fastpcrf-14.0 dpiutils-14.0 fastradius-14.0

Example rollback to version 12.4:

yum downgrade fastdpi-12.4-0 fastpcrf-12.4-0 dpiutils-12.4-0 fastradius-12.4-0

After rollback, service restart is required:

service fastdpi stop
service fastpcrf restart
service fastdpi start

Customers using bras functionality must take changes into account when upgrading to new versions.
Updating the linux kernel may break binary compatibility with kernel abi and cause issues with network driver loading.
If the kernel was updated, temporarily configure booting the previous version via grub by setting the required default parameter value in the /etc/grub.conf file.