Deploying EDB Postgres Distributed using Trusted Postgres Architect
===================================================================

The standard way of deploying EDB Postgres Distributed in a self-managed
setting is to use EDB’s deployment tool: `Trusted Postgres
Architect </tpa/latest/>`__ (TPA). This applies to physical and virtual
machines, both self-hosted and in the cloud (EC2),

..  Note Get started with PGD quickly ::
   If you want to experiment with a local deployment as quickly as possible, you can use your free-trial account and  :ref:`Deploying an EDB Postgres Distributed example cluster on Docker <Deploying an EDB Postgres Distributed example cluster on Docker>`  to configure, provision, and deploy a PGD 5 Always-On cluster on Docker. If deploying to the cloud is your aim, use that same free-trial account and  :ref:`Deploying and EDB Postgres Distributed example cluster on AWS <Deploying an EDB Postgres Distributed example cluster on AWS>`  to get a PGD 5 cluster on your own Amazon account.

You can also use your free-trial account and :ref:`Deploying EDB Postgres Distributed using Trusted Postgres Architect <Deploying EDB Postgres Distributed using Trusted Postgres Architect>`  (TPA) to
 :ref:`deploy directly to your own bare metal servers <Deploying EDB Postgres Distributed using Trusted Postgres Architect>`  .

Prerequisite: Install TPA
-------------------------

Before you can use TPA to deploy PGD, you must install TPA. Follow the
 :ref:`installation instructions in the Trusted Postgres Architect documentation <Deploying EDB Postgres Distributed using Trusted Postgres Architect>`  before continuing.

Configure
---------

The ``tpaexec configure`` command generates a simple YAML configuration
file to describe a cluster, based on the options you select. The
configuration is ready for immediate use, and you can modify it to
better suit your needs. Editing the configuration file is the usual way
to make any configuration changes to your cluster both before and after
it’s created.

The syntax is:

::

   tpaexec configure <cluster_dir> --architecture <architecture_name> [options]

The available configuration options include:

.. csv-table::
  :header: Flags,Description
  :widths: 10,30
  :align: left
  :class: longtable

  `--architecture`,Required. Set to `PGD-Always-ON` for EDB Postgres Distributed deployments.
  `–-postgresql <version>` 　 or 　 `--edb-postgres-advanced <version>` 　 or 　 `--edb-postgres-extended <version>`,"Required. Specifies the distribution and version of Postgres to use. For more details, see  :ref:`PGD/TPA upgrades <Deploying EDB Postgres Distributed using Trusted Postgres Architect>` ."
  `--redwood` or `--no-redwood`,Required when `--edb-postgres-advanced` flag is present. Specifies whether Oracle database compatibility features are desired.
  `--location-names l1 l2 l3`,Required. Specifies the names of the locations to deploy PGD to.
  `--data-nodes-per-location N`,Specifies the number of data nodes per location. Default is 3.
  `--add-witness-node-per-location`,"For an even number of data nodes per location, adds witness nodes to allow for local consensus. Enabled by default for 2 data node locations."
  `--add-proxy-nodes-per-location`,Whether to separate PGD proxies from data nodes and how many to configure. By default one proxy is configured and cohosted for each data node.
  `--pgd-proxy-routing globalIlocal`,Whether PGD Proxy routing is handled on a global or local (per-location) basis.
  `--add-witness-only-location loc`,Designates one of the cluster locations as witness-only (no data nodes are present in that location).
  `--enable-camo`,Sets up a CAMO pair in each location. Works only with 2 data nodes per location.

More configuration options are listed in the TPA documentation for
 :ref:`PGD-Always-ON <Deploying EDB Postgres Distributed using Trusted Postgres Architect>`  .

For example:

::

   [tpa]$ tpaexec configure ~/clusters/speedy \
            --architecture PGD-Always-ON \
            --platform aws \
            --edb-postgres-advanced 15 \
            --redwood \
            --location-names eu-west-1 eu-north-1 eu-central-1 \
            --data-nodes-per-location 3 \
            --pgd-proxy-routing global

The first argument must be the cluster directory, for example,
``speedy`` or ``~/clusters/speedy`` . (The cluster is named ``speedy``
in both cases.) We recommend that you keep all your clusters in a common
directory, for example, ``~/clusters`` . The next argument must be
``--architecture`` to select an architecture, followed by options.

The command creates a directory named ``~/clusters/speedy`` and
generates a configuration file named ``config.yml`` that follows the
layout of the PGD-Always-ON architecture. You can use the
``tpaexec configure --architecture PGD-Always-ON --help`` command to see
the values that are supported for the configuration options in this
architecture.

In the example, the options select:

-  An AWS deployment (``--platform aws`` )

-  EDB Postgres Advanced Server, version 15 and Oracle compatibility
   (``--edb-postgres-advanced 15`` and ``--redwood`` )

-  Three locations
   (``--location-names eu-west-1 eu-north-1 eu-central-1`` )

-  Three data nodes at each location (``--data-nodes-per-location 3`` )

-  Proxy routing policy of global (``--pgd-proxy-routing global`` )

Common configuration options
^^^^^^^^^^^^^^^^^^^^^^^^^^^^

Other configuration options include the following.

Owner
^^^^^

Every cluster must be directly traceable to a person responsible for the
provisioned resources.

By default, a cluster is tagged as being owned by the login name of the
user running ``tpaexec provision`` . If this name doesn’t identify a
person (for example, ``postgres`` , ``ec2-user`` ), you must specify
``--owner SomeId`` to set an identifiable owner.

You can use your initials, “Firstname Lastname”, or any text that
identifies you uniquely.

Platform options
^^^^^^^^^^^^^^^^

The default value for ``--platform`` is ``aws`` , which is the platform
supported by the PGD-Always-ON architecture.

Specify ``--region`` to specify any existing AWS region that you have
access to and that allows you to create the required number of
instances. The default region is eu-west-1.

Specify ``--instance-type`` with any valid instance type for AWS. The
default is t3.micro.

Subnet selection
^^^^^^^^^^^^^^^^

By default, each cluster is assigned a random /28 subnet under 10.33/16.
However, depending on the architecture, there can be one or more
subnets, and each subnet can be anywhere between a /24 and a /29.

Specify ``--subnet`` to use a particular subnet, for example,
``--subnet 192.0.2.128/27`` .

Disk space
^^^^^^^^^^

Specify ``--root-volume-size`` to set the size of the root volume in GB,
for example, ``--root-volume-size 64`` . The default is 16GB. Depending
on the image used to create instances, there might be a minimum size for
the root volume.

For architectures that support separate Postgres and Barman volumes:

-  Specify ``--postgres-volume-size`` to set the size of the Postgres
   volume in GB. The default is 16GB.

-  Specify ``--barman-volume-size`` to set the size of the Barman volume
   in GB. The default is 32GB.

Distribution
^^^^^^^^^^^^

Specify ``--os`` or ``--distribution`` to specify the OS to use on the
cluster’s instances. The value is case sensitive.

The selected platform determines the distributions that are available
and the one that’s used by default. For more details, see
``tpaexec info platforms/<platformname>`` .

In general, you can use ``Debian`` , ``RedHat`` , and ``Ubuntu`` to
select TPA images that have Postgres and other software preinstalled (to
reduce deployment times). To use stock distribution images instead,
append ``-minimal`` to the value, for example,
``--distribution Debian-minimal`` .

Repositories
^^^^^^^^^^^^

When using TPA to deploy PDG 5 and later, TPA selects repositories from
EDB Repos 2.0. All software is sourced from these repositories.

To use `EDB Repos 2.0 <https://www.enterprisedb.com/repos/>`_  , you must use
``export EDB_SUBSCRIPTION_TOKEN=xxx`` before you run tpaexec. You can
get your subscription token from `the web
interface <https://www.enterprisedb.com/repos-downloads>`__.

Optionally, use ``--edb-repositories repository …`` to specify EDB
repositories in addition to the default repository to install on each
instance.

Software versions
^^^^^^^^^^^^^^^^^

By default, TPA uses the latest major version of Postgres. Specify
``--postgres-version`` to install an earlier supported major version, or
specify both version and distribution using one of the flags described
under :ref:`Configure <Configure>`  .

By default, TPA installs the latest version of every package, which is
usually the desired behavior. However, in some testing scenarios, you
might need to select specific package versions. For example:

::

   - -postgres-package-version 10.4-2.pgdg90+1
   - -repmgr-package-version 4.0.5-1.pgdg90+1
   - -barman-package-version 2.4-1.pgdg90+1
   - -pglogical-package-version 2.2.0*
   - -bdr-package-version 3.0.2*
   - -pgbouncer-package-version 1.8*

Specify ``--extra-packages`` or ``--extra-postgres-packages`` to install
more packages. The former lists packages to install along with system
packages. The latter lists packages to install later along with Postgres
packages. (If you mention packages that depend on Postgres in the former
list, the installation fails because Postgres isn’t yet installed.) The
arguments are passed on to the package manager for installation without
any modifications.

The ``--extra-optional-packages`` option behaves like
``--extra-packages`` , but it’s not an error if the named packages can’t
be installed.

Hostnames
^^^^^^^^^

By default, ``tpaexec configure`` randomly selects as many hostnames as
it needs from a preapproved list of several dozen names, which is enough
for most clusters.

Specify ``--hostnames-from`` to select names from a different list, for
example, if you need more names than are available in the supplied list.
The file must contain one hostname per line.

Specify ``--hostnames-pattern`` to restrict hostnames to those matching
the egrep-syntax pattern. If you choose to do this, you must ensure that
the pattern matches only valid hostnames ([a-zA-Z0-9-]) and finds enough
of them.

Locations
^^^^^^^^^

By default, ``tpaexec configure`` uses the names first, second, and so
on for any locations used by the selected architecture.

Specify ``--location-names`` to provide more meaningful names for each
location.

Provision
---------

The ``tpaexec provision`` command creates instances and other resources
required by the cluster. The details of the process depend on the
architecture (for example, PGD-Always-ON) and platform (for example,
AWS) that you selected while configuring the cluster.

For example, given AWS access with the necessary privileges, TPA
provisions EC2 instances, VPCs, subnets, routing tables, internet
gateways, security groups, EBS volumes, elastic IPs, and so on.

You can also provision existing servers by selecting the ``bare``
platform and providing connection details. Whether these are bare metal
servers or those provisioned separately on a cloud platform, they can be
used as if they had been created by TPA.

You aren’t restricted to a single platform. You can spread your cluster
out across some AWS instances in multiple regions and some on-premise
servers or servers in other data centres, as needed.

At the end of the provisioning stage, you will have the required number
of instances with the basic operating system installed, which TPA can
access using SSH (with sudo to root).

Deploy
------

The ``tpaexec deploy`` command installs and configures Postgres and
other software on the provisioned servers. TPA can create the servers,
but it doesn’t matter who created them so long as SSH and sudo access
are available. This includes setting up replication, backups, and so on.

At the end of the deployment stage, EDB Postgres Distributed is up and
running.

Test
----

The ``tpaexec test`` command executes various architecture and
platform-specific tests against the deployed cluster to ensure that it’s
working as expected.

At the end of the testing stage, you have a fully functioning cluster.

For more information, see :ref:`Deploying EDB Postgres Distributed using Trusted Postgres Architect <Deploying EDB Postgres Distributed using Trusted Postgres Architect>`  .
