Synnefo

.. _admin-guide:

Synnefo Administrator's Guide

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

This is the complete Synnefo Administrator's Guide.

General Synnefo Architecture

============================

The following graph shows the whole Synnefo architecture and how it interacts

with multiple Ganeti clusters. We hope that after reading the Administrator's

Guide you will be able to understand every component and all the interactions

between them. It is a good idea to first go through the Quick Administrator's

Guide before proceeding.

.. image:: images/synnefo-arch2.png

   :width: 100%

   :target: _images/synnefo-arch2.png

Identity Service (Astakos)

==========================

Overview

--------

Authentication methods

~~~~~~~~~~~~~~~~~~~~~~

Local Authentication

````````````````````

LDAP Authentication

```````````````````

.. _shibboleth-auth:

Shibboleth Authentication

`````````````````````````

Astakos can delegate user authentication to a Shibboleth federation.

To setup shibboleth, install package::

  apt-get install libapache2-mod-shib2

Change appropriately the configuration files in ``/etc/shibboleth``.

Add in ``/etc/apache2/sites-available/synnefo-ssl``::

  ShibConfig /etc/shibboleth/shibboleth2.xml

  Alias      /shibboleth-sp /usr/share/shibboleth

  <Location /im/login/shibboleth>

    AuthType shibboleth

    ShibRequireSession On

    ShibUseHeaders On

    require valid-user

  </Location>

and before the line containing::

  ProxyPass        / http://localhost:8080/ retry=0

add::

  ProxyPass /Shibboleth.sso !

Then, enable the shibboleth module::

  a2enmod shib2

After passing through the apache module, the following tokens should be

available at the destination::

  eppn # eduPersonPrincipalName

  Shib-InetOrgPerson-givenName

  Shib-Person-surname

  Shib-Person-commonName

  Shib-InetOrgPerson-displayName

  Shib-EP-Affiliation

  Shib-Session-ID

Finally, add 'shibboleth' in ``ASTAKOS_IM_MODULES`` list. The variable resides

inside the file ``/etc/synnefo/20-snf-astakos-app-settings.conf``

Architecture

------------

Prereqs

-------

Installation

------------

Configuration

-------------

Working with Astakos

--------------------

User activation methods

~~~~~~~~~~~~~~~~~~~~~~~

When a new user signs up, he/she is not marked as active. You can see his/her

state by running (on the machine that runs the Astakos app):

.. code-block:: console

   $ snf-manage user-list

There are two different ways to activate a new user. Both need access to a

running :ref:`mail server <mail-server>`.

Manual activation

`````````````````

You can manually activate a new user that has already signed up, by sending

him/her an activation email. The email will contain an approriate activation

link, which will complete the activation process if followed. You can send the

email by running:

.. code-block:: console

   $ snf-manage user-activation-send <user ID or email>

Be sure to have already setup your mail server and defined it in your Synnefo

settings, before running the command.

Automatic activation

````````````````````

FIXME: Describe Regex activation method

Astakos advanced operations

---------------------------

Adding "Terms of Use"

~~~~~~~~~~~~~~~~~~~~~

Astakos supports versioned terms-of-use. First of all you need to create an

html file that will contain your terms. For example, create the file

``/usr/share/synnefo/sample-terms.html``, which contains the following:

.. code-block:: console

   <h1>~okeanos terms</h1>

   These are the example terms for ~okeanos

Then, add those terms-of-use with the snf-manage command:

.. code-block:: console

   $ snf-manage term-add /usr/share/synnefo/sample-terms.html

Your terms have been successfully added and you will see the corresponding link

appearing in the Astakos web pages' footer.

Enabling reCAPTCHA

~~~~~~~~~~~~~~~~~~

Astakos supports the `reCAPTCHA <http://www.google.com/recaptcha>`_ feature.

If enabled, it protects the Astakos forms from bots. To enable the feature, go

to https://www.google.com/recaptcha/admin/create and create your own reCAPTCHA

key pair. Then edit ``/etc/synnefo/20-snf-astakos-app-settings.conf`` and set

the corresponding variables to reflect your newly created key pair. Finally, set

the ``ASTAKOS_RECAPTCHA_ENABLED`` variable to ``True``:

.. code-block:: console

   ASTAKOS_RECAPTCHA_PUBLIC_KEY = 'example_recaptcha_public_key!@#$%^&*('

   ASTAKOS_RECAPTCHA_PRIVATE_KEY = 'example_recaptcha_private_key!@#$%^&*('

   ASTAKOS_RECAPTCHA_ENABLED = True

Restart the service on the Astakos node(s) and you are ready:

.. code-block:: console

   # /etc/init.d/gunicorn restart

Checkout your new Sign up page. If you see the reCAPTCHA box, you have setup

everything correctly.

File Storage Service (Pithos)

=============================

Overview

--------

Architecture

------------

Prereqs

-------

Installation

------------

Configuration

-------------

Working with Pithos

-------------------

Pithos advanced operations

--------------------------

Compute/Network/Image Service (Cyclades)

========================================

Compute Overview

----------------

Network Overview

----------------

Image Overview

--------------

Architecture

------------

Asynchronous communication with Ganeti backends

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Synnefo uses Google Ganeti backends for VM cluster management. In order for

Cyclades to be able to handle thousands of user requests, Cyclades and Ganeti

communicate asynchronously. Briefly, requests are submitted to Ganeti through

Ganeti's RAPI/HTTP interface, and then asynchronous notifications about the

progress of Ganeti jobs are being created and pushed upwards to Cyclades. The

architecture and communication with a Ganeti backend is shown in the graph

below:

.. image:: images/cyclades-ganeti-communication.png

   :width: 50%

   :target: _images/cyclades-ganeti-communication.png

The Cyclades API server is responsible for handling user requests. Read-only

requests are directly served by looking up the Cyclades DB. If the request

needs an action in the Ganeti backend, Cyclades submit jobs to the Ganeti

master using the `Ganeti RAPI interface

<http://docs.ganeti.org/ganeti/2.2/html/rapi.html>`_.

While Ganeti executes the job, `snf-ganeti-eventd`, `snf-ganeti-hook` and

`snf-progress-monitor` are monitoring the progress of the job and send

corresponding messages to the RabbitMQ servers. These components are part

of `snf-cyclades-gtools` and must be installed on all Ganeti nodes. Specially:

* *snf-ganeti-eventd* sends messages about operations affecting the operating

  state of instances and networks. Works by monitoring the Ganeti job queue.

* *snf-ganeti_hook* sends messages about the NICs of instances. It includes a

  number of `Ganeti hooks <http://docs.ganeti.org/ganeti/2.2/html/hooks.html>`_

  for customisation of operations.

* *snf-progress_monitor* sends messages about the progress of the Image deployment

  phase which is done by the Ganeti OS Definition `snf-image`.

Finally, `snf-dispatcher` consumes messages from the RabbitMQ queues, processes

these messages and properly updates the state of the Cyclades DB. Subsequent

requests to the Cyclades API, will retrieve the updated state from the DB.

Prereqs

-------

Work in progress. Please refer to :ref:`quick administrator quide <quick-install-admin-guide>`.

Installation

------------

Work in progress. Please refer to :ref:`quick administrator quide <quick-install-admin-guide>`.

Configuration

-------------

Work in progress. Please refer to :ref:`quick administrator quide <quick-install-admin-guide>`.

Working with Cyclades

---------------------

Managing Ganeti Backends

~~~~~~~~~~~~~~~~~~~~~~~~

Since v0.11, Synnefo is able to manage multiple Ganeti clusters (backends)

making it capable to scale linearly to tens of thousands of VMs. Backends

can be dynamically added or removed via `snf-manage` commands.

Each newly created VM is allocated to a Ganeti backend by the Cyclades backend

allocator. The VM is "pinned" to this backend, and can not change through its

lifetime. The backend allocator decides in which backend to spawn the VM based

on the available resources of each backend, trying to balance the load between

them.

Handling of Networks, as far as backends are concerned, is based on whether the

network is public or not. Public networks are created through the `snf-manage

network-create` command, and are only created on one backend. Private networks

are created on all backends, in order to ensure that VMs residing on different

backends can be connected to the same private network.

Listing existing backends

`````````````````````````

To list all the Ganeti backends known to Synnefo, we run:

.. code-block:: console

   $ snf-manage backend-list

Adding a new Ganeti backend

```````````````````````````

Backends are dynamically added under the control of Synnefo with `snf-manage

backend-add` command. In this section it is assumed that a Ganeti cluster,

named ``cluster.example.com`` is already up and running and configured to be

able to host Synnefo VMs.

To add this Ganeti cluster, we run:

.. code-block:: console

   $ snf-manage backend-add --clustername=cluster.example.com --user="synnefo_user" --pass="synnefo_pass"

where ``clustername`` is the Cluster hostname of the Ganeti cluster, and

``user`` and ``pass`` are the credentials for the `Ganeti RAPI user

<http://docs.ganeti.org/ganeti/2.2/html/rapi.html#users-and-passwords>`_.  All

backend attributes can be also changed dynamically using the `snf-manage

backend-modify` command.

``snf-manage backend-add`` will also create all existing private networks to

the new backend. You can verify that the backend is added, by running

`snf-manage backend-list`.

Note that no VMs will be spawned to this backend, since by default it is in a

``drained`` state after addition and also it has no public network assigned to

it.

So, first you need to create its public network, make sure everything works as

expected and finally make it active by un-setting the ``drained`` flag. You can

do this by running:

.. code-block:: console

   $ snf-manage backend-modify --drained=False <backend_id>

Removing an existing Ganeti backend

```````````````````````````````````

In order to remove an existing backend from Synnefo, we run:

.. code-block:: console

   # snf-manage backend-remove <backend_id>

This command will fail if there are active VMs on the backend. Also, the

backend is not cleaned before removal, so all the Synnefo private networks

will be left on the Ganeti nodes. You need to remove them manually.

Allocation of VMs in Ganeti backends

````````````````````````````````````

As already mentioned, the Cyclades backend allocator is responsible for

allocating new VMs to backends. This allocator does not choose the exact Ganeti

node that will host the VM but just the Ganeti backend. The exact node is

chosen by the Ganeti cluster's allocator (hail).

The decision about which backend will host a VM is based on the available

resources. The allocator computes a score for each backend, that shows its load

factor, and the one with the minimum score is chosen. The admin can exclude

backends from the allocation phase by marking them as ``drained`` by running:

.. code-block:: console

   $ snf-manage backend-modify --drained=True <backend_id>

The backend resources are periodically updated, at a period defined by

the ``BACKEND_REFRESH_MIN`` setting, or by running `snf-manage backend-update-status`

command. It is advised to have a cron job running this command at a smaller

interval than ``BACKEND_REFRESH_MIN`` in order to remove the load of refreshing

the backends stats from the VM creation phase.

Finally, the admin can decide to have a user's VMs being allocated to a

specific backend, with the ``BACKEND_PER_USER`` setting. This is a mapping

between users and backends. If the user is found in ``BACKEND_PER_USER``, then

Synnefo allocates all his/hers VMs to the specific backend in the variable,

even if is marked as drained (useful for testing).

Managing Virtual Machines

~~~~~~~~~~~~~~~~~~~~~~~~~

As mentioned, Cyclades uses Ganeti for management of VMs. The administrator can

handle Cyclades VMs just like any other Ganeti instance, via `gnt-instance`

commands. All Ganeti instances that belong to Synnefo, are separated from

others, by a prefix in their names. This prefix is defined in

``BACKEND_PREFIX_ID`` setting in

``/etc/synnefo/20-snf-cyclades-app-backend.conf``.

Apart from handling instances directly in the Ganeti level, a number of `snf-manage`

commands are available:

* ``snf-manage server-list``: List servers

* ``snf-manage server-show``: Show information about a server in the Cyclades DB

* ``snf-manage server-inspect``: Inspect the state of a server both in DB and Ganeti

* ``snf-manage server-modify``: Modify the state of a server in the Cycldes DB

* ``snf-manage server-create``: Create a new server

* ``snf-manage server-import``: Import an existing Ganeti instance to Cyclades

Managing Virtual Networks

~~~~~~~~~~~~~~~~~~~~~~~~~

Cyclades is able to create and manage Virtual Networks. Networking is

desployment specific and must be customized based on the specific needs of the

system administrator. For better understanding of networking please refer to

the :ref:`Network <networks>` section.

Exactly as Cyclades VMs can be handled like Ganeti instances, Cyclades Networks

can also by handled as Ganeti networks, via `gnt-network commands`. All Ganeti

networks that belong to Synnefo are named with the prefix

`${BACKEND_PREFIX_ID}-net-`.

There are also the following `snf-manage` commands for managing networks:

* ``snf-manage network-list``: List networks

* ``snf-manage network-show``: Show information about a network in the Cyclades DB

* ``snf-manage network-inspect``: Inspect the state of the network in DB and Ganeti backends

* ``snf-manage network-modify``: Modify the state of a network in the Cycldes DB

* ``snf-manage network-create``: Create a new network

* ``snf-manage network-remove``: Remove an existing network

Managing Network Resources

``````````````````````````

Proper operation of the Cyclades Network Service depends on the unique

assignment of specific resources to each type of virtual network. Specifically,

these resources are:

* IP addresses. Cyclades creates a Pool of IPs for each Network, and assigns a

  unique IP address to each VM, thus connecting it to this Network. You can see

  the IP pool of each network by running `snf-manage network-inspect

  <network_ID>`. IP pools are automatically created and managed by Cyclades,

  depending on the subnet of the Network.

* Bridges corresponding to physical VLANs, which are required for networks of

  type `PRIVATE_PHYSICAL_VLAN`.

* One Bridge corresponding to one physical VLAN which is required for networks of

  type `PRIVATE_MAC_PREFIX`.

Cyclades allocates those resources from pools that are created by the

administrator with the `snf-manage pool-create` management command.

Pool Creation

`````````````

Pools are created using the `snf-manage pool-create` command:

.. code-block:: console

   # snf-manage pool-create --type=bridge --base=prv --size=20

will create a pool of bridges, containing bridges prv1, prv2,..prv21.

You can verify the creation of the pool, and check its contents by running:

.. code-block:: console

   # snf-manage pool-list

   # snf-manage pool-show --type=bridge 1

With the same commands you can handle a pool of MAC prefixes. For example:

.. code-block:: console

   # snf-manage pool-create --type=mac-prefix --base=aa:00:0 --size=65536

will create a pool of MAC prefixes from ``aa:00:1`` to ``b9:ff:f``. The MAC

prefix pool is responsible for providing only unicast and locally administered

MAC addresses, so many of these prefixes will be externally reserved, to

exclude from allocation.

Cyclades advanced operations

----------------------------

Reconciliation mechanism

~~~~~~~~~~~~~~~~~~~~~~~~

On certain occasions, such as a Ganeti or RabbitMQ failure, the state of

Cyclades database may differ from the real state of VMs and networks in the

Ganeti backends. The reconciliation process is designed to synchronize

the state of the Cyclades DB with Ganeti. There are two management commands

for reconciling VMs and Networks

Reconciling Virtual Machines

````````````````````````````

Reconciliation of VMs detects the following conditions:

 * Stale DB servers without corresponding Ganeti instances

 * Orphan Ganeti instances, without corresponding DB entries

 * Out-of-sync state for DB entries wrt to Ganeti instances

To detect all inconsistencies you can just run:

.. code-block:: console

  $ snf-manage reconcile-servers

Adding the `--fix-all` option, will do the actual synchronization:

.. code-block:: console

  $ snf-manage reconcile --fix-all

Please see ``snf-manage reconcile --help`` for all the details.

Reconciling Networks

````````````````````

Reconciliation of Networks detects the following conditions:

  * Stale DB networks without corresponding Ganeti networks

  * Orphan Ganeti networks, without corresponding DB entries

  * Private networks that are not created to all Ganeti backends

  * Unsynchronized IP pools

To detect all inconsistencies you can just run:

.. code-block:: console

  $ snf-manage reconcile-networks

Adding the `--fix-all` option, will do the actual synchronization:

.. code-block:: console

  $ snf-manage reconcile-networks --fix-all

Please see ``snf-manage reconcile-networks --help`` for all the details.

Block Storage Service (Archipelago)

===================================

Overview

--------

Archipelago offers Copy-On-Write snapshotable volumes. Pithos images can be used

to provision a volume with Copy-On-Write semantics (i.e. a clone). Snapshots

offer a unique deduplicated image of a volume, that reflects the volume state

during snapshot creation and are indistinguishable from a Pithos image.

Archipelago is used by Cyclades and Ganeti for fast provisioning of VMs based on

CoW volumes. Moreover, it enables live migration of thinly-provisioned VMs with

no physically shared storage.

Archipelago Architecture

------------------------

.. image:: images/archipelago-architecture.png

   :width: 50%

   :target: _images/archipelago-architecture.png

.. _syn+archip+rados:

Overview of Synnefo + Archipelago + RADOS

-----------------------------------------

.. image:: images/synnefo-arch3.png

   :width: 100%

   :target: _images/synnefo-arch3.png

Prereqs

-------

The administrator must initialize the storage backend where archipelago volume

blocks will reside.

In case of a files backend, the administrator must create two directories. One

for the archipelago data blocks and one for the archipelago map blocks. These

should probably be over shared storage to enable sharing archipelago volumes

between multiple nodes. He or she, must also be able to supply a directory where

the pithos data and map blocks reside.

In case of a RADOS backend, the administrator must create two rados pools, one

for data blocks, and one for the map blocks. These pools, must be the same pools

used in pithos, in order to enable volume creation based on pithos images.

Installation

------------

Archipelago consists of

* ``libxseg0``: libxseg used to communicate over shared memory segments

* ``python-xseg``: python bindings for libxseg

* ``archipelago-kernel-dkms``: contains archipelago kernel modules to provide

  block devices to be used as vm disks

* ``python-archipelago``: archipelago python module. Includes archipelago and

  vlmc functionality.

* ``archipelago``: user space tools and peers for the archipelago management and

  volume composition

* ``archipelago-ganeti``: ganeti ext storage scripts, that enable ganeti to

  provision VMs over archipelago

Performing

.. code-block:: console

  $ apt-get install archipelago-ganeti 

should fetch all the required packages and get you up 'n going with archipelago

Bare in mind, that custom librados is required, which is provided in the apt

repo of GRNet.

For now, librados is a dependency of archipelago, even if you do not intend to

use archipelago over RADOS.

Configuration

-------------

Archipelago should work out of the box with a RADOS backend, but basic

configuration can be done in ``/etc/default/archipelago`` .

If you wish to change the storage backend to files, set

.. code-block:: console

   STORAGE="files"

and provide the appropriate settings for files storage backend in the conf file.

These are:

* ``FILED_IMAGES``: directory for archipelago data blocks.

* ``FILED_MAPS``: directory for archipelago map blocks.

* ``PITHOS``: directory of pithos data blocks.

* ``PITHOSMAPS``: directory of pithos map blocks.

The settings for RADOS storage backend are:

* ``RADOS_POOL_MAPS``: The pool where archipelago and pithos map blocks reside.

* ``RADOS_POOL_BLOCKS``: The pool where archipelago and pithos data blocks

  reside.

Examples can be found in the conf file.

Be aware that archipelago infrastructure doesn't provide default values for this

settings. If they are not set in the conf file, archipelago will not be able to

function.

Archipelago also provides ``VERBOSITY`` config options to control the output

generated by the userspace peers.

The available options are:

* ``VERBOSITY_BLOCKERB``

* ``VERBOSITY_BLOCKERM``

* ``VERBOSITY_MAPPER``

* ``VERBOSITY_VLMC``

and the available values are:

* 0 : Error only logging.

* 1 : Warning logging.

* 2 : Info logging.

* 3 : Debug logging. WARNING: This options produces tons of output, but the

  logrotate daemon should take care of it.

Working with Archipelago

------------------------

``archipelago`` provides basic functionality for archipelago.

Usage:

.. code-block:: console

  $ archipelago [-u] command

Currently it supports the following commands:

* ``start [peer]``

  Starts archipelago or the specified peer.

* ``stop [peer]``

  Stops archipelago or the specified peer.

* ``restart [peer]``

  Restarts archipelago or the specified peer.

* ``status``

  Show the status of archipelago.

Available peers: ``blockerm``, ``blockerb``, ``mapperd``, ``vlmcd``.

``start``, ``stop``, ``restart`` can be combined with the ``-u / --user`` option

to affect only the userspace peers supporting archipelago.

Archipelago advanced operations

-------------------------------

The ``vlmc`` tool provides a way to interact with archipelago volumes

* ``vlmc map <volumename>``: maps the volume to a xsegbd device.

* ``vlmc unmap </dev/xsegbd[1-..]>``: unmaps the specified device from the

  system.

* ``vlmc create <volumename> --snap <snapname> --size <size>``: creates a new

  volume named <volumename> from snapshot name <snapname> with size <size>.

  The ``--snap`` and ``--size`` are optional, but at least one of them is

  mandatory. e.g:

  ``vlmc create <volumename> --snap <snapname>`` creates a volume named

  volumename from snapshot snapname. The size of the volume is the same as

  the size of the snapshot.

  ``vlmc create <volumename> --size <size>`` creates an empty volume of size

  <size> named <volumename>.

* ``vlmc remove <volumename>``: removes the volume and all the related

  archipelago blocks from storage.

* ``vlmc list``: provides a list of archipelago volumes. Currently only works

  with RADOS storage backend.

* ``vlmc info <volumename>``: shows volume information. Currently returns only

  volume size.

* ``vlmc open <volumename>``: opens an archipelago volume. That is, taking all

  the necessary locks and also make the rest of the infrastructure aware of the

  operation.

  This operation succeeds if the volume is alread opened.

* ``vlmc close <volumename>``: closes an archipelago volume. That is, performing

  all the necessary functions in the insfrastrure to successfully release the

  volume. Also releases all the acquired locks.

  ``vlmc close`` should be performed after a ``vlmc open`` operation.

* ``vlmc lock <volumename>``: locks a volume. This step allow the administrator

  to lock an archipelago volume, independently from the rest of the

  infrastrure.

* ``vlmc unlock [-f] <volumename>``: unlocks a volume. This allow the

  administrator to unlock a volume, independently from the rest of the

  infrastructure.

  The unlock option can be performed only by the blocker that acquired the lock

  in the first place. To unlock a volume from another blocker, ``-f`` option

  must be used to break the lock.

The "kamaki" API client

=======================

To upload, register or modify an image you will need the **kamaki** tool.

Before proceeding make sure that it is configured properly. Verify that

*image_url*, *storage_url*, and *token* are set as needed:

.. code-block:: console

   $ kamaki config list

To chage a setting use ``kamaki config set``:

.. code-block:: console

   $ kamaki config set image_url https://cyclades.example.com/plankton

   $ kamaki config set storage_url https://pithos.example.com/v1

   $ kamaki config set token ...

Upload Image

------------

As a shortcut, you can configure a default account and container that will be

used by the ``kamaki store`` commands:

.. code-block:: console

   $ kamaki config set storage_account images@example.com

   $ kamaki config set storage_container images

If the container does not exist, you will have to create it before uploading

any images:

.. code-block:: console

   $ kamaki store create images

You are now ready to upload an image. You can upload it with a Pithos+ client,

or use kamaki directly:

.. code-block:: console

   $ kamaki store upload ubuntu.iso

You can use any Pithos+ client to verify that the image was uploaded correctly.

The full Pithos URL for the previous example will be

``pithos://images@example.com/images/ubuntu.iso``.

Register Image

--------------

To register an image you will need to use the full Pithos+ URL. To register as

a public image the one from the previous example use:

.. code-block:: console

   $ kamaki glance register Ubuntu pithos://images@example.com/images/ubuntu.iso --public

The ``--public`` flag is important, if missing the registered image will not

be listed by ``kamaki glance list``.

Use ``kamaki glance register`` with no arguments to see a list of available

options. A more complete example would be the following:

.. code-block:: console

   $ kamaki glance register Ubuntu pithos://images@example.com/images/ubuntu.iso \

            --public --disk-format diskdump --property kernel=3.1.2

To verify that the image was registered successfully use:

.. code-block:: console

   $ kamaki glance list -l

Miscellaneous

=============

.. RabbitMQ

RabbitMQ Broker

---------------

Queue nodes run the RabbitMQ sofware, which provides AMQP functionality. To

guarantee high-availability, more than one Queue nodes should be deployed, each

of them belonging to the same `RabbitMQ cluster

<http://www.rabbitmq.com/clustering.html>`_. Synnefo uses the RabbitMQ

active/active `High Available Queues <http://www.rabbitmq.com/ha.html>`_ which

are mirrored between two nodes within a RabbitMQ cluster.

The RabbitMQ nodes that form the cluster, are declared to Synnefo through the

`AMQP_HOSTS` setting. Each time a Synnefo component needs to connect to

RabbitMQ, one of these nodes is chosen in a random way. The client that Synnefo

uses to connect to RabbitMQ, handles connection failures transparently and

tries to reconnect to a different node. As long as one of these nodes are up

and running, functionality of Synnefo should not be downgraded by the RabbitMQ

node failures.

All the queues that are being used are declared as durable, meaning that

messages are persistently stored to RabbitMQ, until they get successfully

processed by a client.

Currently, RabbitMQ is used by the following components:

* `snf-ganeti-eventd`, `snf-ganeti-hook` and `snf-progress-monitor`:

  These components send messages concerning the status and progress of

  jobs in the Ganeti backend.

* `snf-dispatcher`: This daemon, consumes the messages that are sent from

  the above components, and updates the Cyclades DB accordingly.

Installation

~~~~~~~~~~~~

Please check the RabbitMQ documentation which covers extensively the

`installation of RabbitMQ server <http://www.rabbitmq.com/download.html>`_ and

the setup of a `RabbitMQ cluster <http://www.rabbitmq.com/clustering.html>`_.

Also, check out the `web management plugin

<http://www.rabbitmq.com/management.html>`_ that can be useful for managing and

monitoring RabbitMQ.

For a basic installation of RabbitMQ on two nodes (node1 and node2) you can do

the following:

On both nodes, install rabbitmq-server and create a Synnefo user:

.. code-block:: console

  $ apt-get install rabbitmq-server

  $ rabbitmqctl add_user synnefo "example_pass"

  $ rabbitmqctl set_permissions synnefo  ".*" ".*" ".*"

Also guarantee that both nodes share the same cookie, by running:

.. code-block:: console

  $ scp node1:/var/lib/rabbitmq/.erlang.cookie node2:/var/lib/rabbitmq/.erlang.cookie

and restart the nodes:

.. code-block:: console

  $ /etc/init.d/rabbitmq-server restart

To setup the RabbitMQ cluster run:

.. code-block:: console

  root@node2: rabbitmqctl stop_app

  root@node2: rabbitmqctl reset

  root@node2: rabbitmqctl cluster rabbit@node1 rabbit@node2

  root@node2: rabbitmqctl start_app

You can verify that the cluster is set up correctly by running:

.. code-block:: console

  root@node2: rabbitmqctl cluster_status

Admin tool: snf-manage

----------------------

``snf-manage`` is a tool used to perform various administrative tasks. It needs

to be able to access the django database, so the following should be able to

import the Django settings.

Additionally, administrative tasks can be performed via the admin web interface

located in /admin. Only users of type ADMIN can access the admin pages. To

change the type of a user to ADMIN, snf-manage can be used:

.. code-block:: console

   $ snf-manage user-modify 42 --type ADMIN

Logging

-------

Logging in Synnefo is using Python's logging module. The module is configured

using dictionary configuration, whose format is described here:

http://docs.python.org/release/2.7.1/library/logging.html#logging-config-dictschema

Note that this is a feature of Python 2.7 that we have backported for use in

Python 2.6.

The logging configuration dictionary is defined in

``/etc/synnefo/10-snf-webproject-logging.conf``

The administrator can have finer logging control by modifying the

``LOGGING_SETUP`` dictionary, and defining subloggers with different handlers

and log levels.  e.g. To enable debug messages only for the API set the level

of 'synnefo.api' to ``DEBUG``

By default, the Django webapp and snf-manage logs to syslog, while

`snf-dispatcher` logs to `/var/log/synnefo/dispatcher.log`.

.. _scale-up:

Scaling up to multiple nodes

============================

Here we will describe how should a large scale Synnefo deployment look like. Make

sure you are familiar with Synnefo and Ganeti before proceeding with this section.

This means you should at least have already set up successfully a working Synnefo

deployment as described in the :ref:`Admin's Quick Installation Guide

<quick-install-admin-guide>` and also read the Administrator's Guide until this

section.

Graph of a scale-out Synnefo deployment

---------------------------------------

Each box in the following graph corresponds to a distinct physical node:

.. image:: images/synnefo-arch2-roles.png

   :width: 100%

   :target: _images/synnefo-arch2-roles.png

The above graph is actually the same with the one at the beginning of this

:ref:`guide <admin-guide>`, with the only difference that here we show the

Synnefo roles of each physical node. These roles are described in the

following section.

.. _physical-node-roles:

Physical Node roles

-------------------

As appears in the previous graph, a scale-out Synnefo deployment consists of

multiple physical nodes that have the following roles:

* **WEBSERVER**: A web server running in front of gunicorn (e.g.: Apache, nginx)

* **ASTAKOS**: The Astakos application (gunicorn)

* **ASTAKOS_DB**: The Astakos database (postgresql)

* **PITHOS**: The Pithos application (gunicorn)

* **PITHOS_DB**: The Pithos database (postgresql)

* **CYCLADES**: The Cyclades application (gunicorn)

* **CYCLADES_DB**: The Cyclades database (postgresql)

* **MQ**: The message queue (RabbitMQ)

* **GANETI_MASTER**: The Ganeti master of a Ganeti cluster

* **GANETI_NODE** : A VM-capable Ganeti node of a Ganeti cluster

You will probably also have:

* **CMS**: The CMS used as a frotend portal for the Synnefo services

* **NS**: A nameserver serving all other Synnefo nodes and resolving Synnefo FQDNs

* **CLIENT**: A machine that runs the Synnefo clients (e.g.: kamaki, Web UI),

              most of the times, the end user's local machine

From this point we will also refer to the following groups of roles:

* **SYNNEFO**: [ **ASTAKOS**, **ASTAKOS_DB**, **PITHOS**, **PITHOS_DB**, **CYCLADES**, **CYCLADES_DB**, **MQ**, **CMS**]

* **G_BACKEND**: [**GANETI_MASTER**, **GANETI_NODE**]

Of course, when deploying Synnefo you can combine multiple of the above roles on a

single physical node, but if you are trying to scale out, the above separation

gives you significant advantages.

So, in the next section we will take a look on what components you will have to

install on each physical node depending on its Synnefo role. We assume the graph's

architecture.

Components for each role

------------------------

When deploying Synnefo in large scale, you need to install different Synnefo

or/and third party components on different physical nodes according to their

Synnefo role, as stated in the previous section.

Specifically:

Role **WEBSERVER**

    * Synnefo components: `None`

    * 3rd party components: Apache

Role **ASTAKOS**

    * Synnefo components: `snf-webproject`, `snf-astakos-app`

    * 3rd party components: Django, Gunicorn

Role **ASTAKOS_DB**

    * Synnefo components: `None`

    * 3rd party components: PostgreSQL

Role **PITHOS**

    * Synnefo components: `snf-webproject`, `snf-pithos-app`, `snf-pithos-webclient`

    * 3rd party components: Django, Gunicorn

Role **PITHOS_DB**

    * Synnefo components: `None`

    * 3rd party components: PostgreSQL

Role **CYCLADES**

    * Synnefo components: `snf-webproject`, `snf-cyclades-app`, `snf-vncauthproxy`

    * 3rd party components: Django Gunicorn

Role **CYCLADES_DB**

    * Synnefo components: `None`

    * 3rd party components: PostgreSQL

Role **MQ**

    * Synnefo components: `None`

    * 3rd party components: RabbitMQ

Role **GANETI_MASTER**

    * Synnefo components: `snf-cyclades-gtools`

    * 3rd party components: Ganeti

Role **GANETI_NODE**

    * Synnefo components: `snf-cyclades-gtools`, `snf-network`, `snf-image`, `nfdhcpd`

    * 3rd party components: Ganeti

Role **CMS**

    * Synnefo components: `snf-webproject`, `snf-cloudcms`

    * 3rd party components: Django, Gunicorn

Role **NS**

    * Synnefo components: `None`

    * 3rd party components: BIND

Role **CLIENT**

    * Synnefo components: `kamaki`, `snf-image-creator`

    * 3rd party components: `None`

Example scale out installation

------------------------------

In this section we describe an example of a medium scale installation which

combines multiple roles on 10 different physical nodes. We also provide a

:ref:`guide <i-synnefo>` to help with such an install.

We assume that we have the following 10 physical nodes with the corresponding

roles:

Node1:

    **WEBSERVER**, **ASTAKOS**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`gunicorn <i-gunicorn>`

        * :ref:`apache <i-apache>`

        * :ref:`snf-webproject <i-webproject>`

        * :ref:`snf-astakos-app <i-astakos>`

Node2:

    **WEBSERVER**, **PITHOS**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`gunicorn <i-gunicorn>`

        * :ref:`apache <i-apache>`

        * :ref:`snf-webproject <i-webproject>`

        * :ref:`snf-pithos-app <i-pithos>`

        * :ref:`snf-pithos-webclient <i-pithos>`

Node3:

    **WEBSERVER**, **CYCLADES**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`gunicorn <i-gunicorn>`

        * :ref:`apache <i-apache>`

        * :ref:`snf-webproject <i-webproject>`

        * :ref:`snf-cyclades-app <i-cyclades>`

        * :ref:`snf-vncauthproxy <i-cyclades>`

Node4:

    **WEBSERVER**, **CMS**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`gunicorn <i-gunicorn>`

        * :ref:`apache <i-apache>`

        * :ref:`snf-webproject <i-webproject>`

        * :ref:`snf-cloudcms <i-cms>`

Node5:

    **ASTAKOS_DB**, **PITHOS_DB**, **CYCLADES_DB**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`postgresql <i-db>`

Node6:

    **MQ**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`rabbitmq <i-mq>`

Node7:

    **GANETI_MASTER**, **GANETI_NODE**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`general <i-backends>`

        * :ref:`ganeti <i-ganeti>`

        * :ref:`snf-cyclades-gtools <i-gtools>`

        * :ref:`snf-network <i-network>`

        * :ref:`snf-image <i-image>`

        * :ref:`nfdhcpd <i-network>`

Node8:

    **GANETI_NODE**

      Guide sections:

        * :ref:`apt <i-apt>`

        * :ref:`general <i-backends>`

        * :ref:`ganeti <i-ganeti>`

        * :ref:`snf-cyclades-gtools <i-gtools>`

        * :ref:`snf-network <i-network>`

        * :ref:`snf-image <i-image>`

        * :ref:`nfdhcpd <i-network>`

Node9:

    **GANETI_NODE**

      Guide sections:

        `Same as Node8`

Node10:

    **GANETI_NODE**

      Guide sections:

        `Same as Node8`

All sections: :ref:`Scale out Guide <i-synnefo>`

Synnefo Upgrade Notes

=====================

.. toctree::

   :maxdepth: 1

   upgrade-0.13

Older Cyclades upgrade notes

============================

.. toctree::

   :maxdepth: 2

   cyclades-upgrade

Changelog

=========