Advanced operations

This section provides guidance on some delicate operations that must be performed manually as they could potentially result in data loss or other types of irrecoverable damage.

Always be careful while performing these operations!

Advanced operations are described in the following sections:

Manual deletion of interfaces

Right now, Astarte only allows deleting draft interfaces, i.e. interfaces with major version 0 and not used by any device.

If you want to delete an interface that has already published data, you must proceed manually with the steps described below. This guide assumes the aim of the operation is deleting the org.astarte-platform.genericsensors.Values interface in the test realm.

The guide requires that cqlsh is connected to the Cassandra/ScyllaDB instance that your Astarte instance is using.

Switch to the target keyspace

The keyspace has the same name of the realm, in this case it is test:

cqlsh> use test;

Find out the interface id

cqlsh:test> SELECT interface_id FROM interfaces
  WHERE name='org.astarte-platform.genericsensors.Values'
  AND major_version = 1;

cqlsh will reply with the interface id:

 interface_id
--------------------------------------
 c238b244-b90f-4c6d-f276-25768bf6abac

Delete the interface

WARNING: This is a destructive step that will erase the correlation between the Interface name and internal ID. Before proceeding, ensure you saved the interface ID, or you will end up with dangling data. Further steps in this guide will require the interface ID.

To delete the interface,

cqlsh:test> DELETE FROM interfaces
  WHERE name='org.astarte-platform.genericsensors.Values'
  AND major_version = 1;

Keep in mind that after this step, all existing devices that attempt to publish on this interface will be disconnected as soon as they try to do so.

Delete interface data

The interface data is stored in a different place depending on the interface type (datastream or properties) and aggregation.

  • Individual datastream interfaces store their data in the individual_datastreams table.
  • Individual properties interfaces store their data in the individual_properties table.
  • Object datastream interfaces store their data in a dedicated table which is created starting from the interface (e.g. an interface called com.test.Sensors with major version 1 creates a com_test_sensors_v1 table in the realm keyspace).

To delete data from object datastreams, a simple DROP of the table where the data is stored is needed.

Deleting data from individual interfaces requires more steps. In this example the interface is an individual datastream, but the procedure for individual properties is the same, but concerns the individual_properties table instead.

To delete the interface data, first all relevant primary keys must be found:

cqlsh:test> SELECT DISTINCT device_id, interface_id, endpoint_id, path FROM individual_datastreams
  WHERE interface_id=c238b244-b90f-4c6d-f276-25768bf6abac ALLOW FILTERING;

This will return a set of primary keys of data belonging to that interface:

 device_id                            | interface_id                         | endpoint_id                          | path
--------------------------------------|--------------------------------------|--------------------------------------|-------------
 41c1c072-d416-4686-ba23-673fe4ad926f | c238b244-b90f-4c6d-f276-25768bf6abac | 33751412-3e77-ad1f-ad57-280cc9fad581 | /test/value
 81c60277-4645-441f-a49b-66a71ce54b83 | c238b244-b90f-4c6d-f276-25768bf6abac | 33751412-3e77-ad1f-ad57-280cc9fad581 | /foo/value
 ...

After that, all data belonging to those primary keys must be deleted:

cqlsh:test> DELETE FROM individual_datastreams
  WHERE device_id=41c1c072-d416-4686-ba23-673fe4ad926f
  AND interface_id=c238b244-b90f-4c6d-f276-25768bf6abac
  AND endpoint_id=33751412-3e77-ad1f-ad57-280cc9fad581
  AND path='/test/value';

cqlsh:test> DELETE FROM individual_datastreams
  WHERE device_id=81c60277-4645-441f-a49b-66a71ce54b83
  AND interface_id=c238b244-b90f-4c6d-f276-25768bf6abac
  AND endpoint_id=33751412-3e77-ad1f-ad57-280cc9fad581
  AND path='/foo/value';
...

devices-by-interface cleanup

If this guide is being used so as to remove a draft interface (i.e. with major version 0) that cannot be deleted since it has data on it, an additional step is required for a complete cleanup.

The information about which devices are using draft interfaces is kept in the kv_store table. You can inspect the groups with:

cqlsh:test> SELECT group FROM kv_store;

The group that has to be deleted may be easily identified by inspecting the returned groups, since it is the one with its name derived from the interface name. For example, if the purpose of the operation is removing all data from the org.astarte-platform.genericevents.DeviceEvents v0.1 interface, the corresponding group in kv_store will be devices-by-interface-org.astarte-platform.genericevents.DeviceEvents-v0.

As the target group is identified, just remove all its entries with:

cqlsh:test> DELETE FROM kv_store WHERE group='devices-by-interface-org.astarte-platform.genericevents.DeviceEvents-v0';

Conclusion

After performing all the steps above, the interface will be completely removed from Astarte. You can then proceed to install a new interface with the same name and major version without any conflict. Remember to remove the interface also on the device side, otherwise devices will keep getting disconnected if they try to publish on the deleted interface.


Manual deletion of a device

Currently, the Astarte API allows for the unregistration and the inhibition of a specific device. If you want to entirely delete a device from your realm along with its data, a manual procedure is required.

This section assumes:

  • that cqlsh is connected to the Cassandra/ScyllaDB instance that your Astarte is using;
  • that astartectl is installed on your machine.

Please keep in mind that this is a destructive procedure. Before moving on, ensure you saved your device ID or you might end up with dangling data and possibly a damaged Astarte deployment.

Retrieve the device uuid

To interact with the device and its data, the device uuid must be retrieved. Assuming that the id of the device to be deleted is k3oPTXaGGGGGGGGGGGGGGG, its uuid can be obtained with the following:

$ astartectl utils device-id to-uuid k3oPTXaGGGGGGGGGGGGGGG
937a0f4d-7686-1861-8618-618618618618

Please, make sure not to lose the device uuid as it will be employed in all the following steps of this section.

Switch to the target keyspace

The keyspace takes its name from the realm, in this case it is test.

cqlsh> use test;

Delete device data on a specific interface

Depending on the interface type and aggregation, data published by the device is stored into different tables:

  • data published over an individual datastream interface are available within the individual_datastreams table;
  • data published over an individual property interface are available within the individual_properties table;
  • data published over an object datastream interfaces are stored in a dedicated table named after the interface name: e.g. an interface called com.test.Sensors with major version 1 creates a com_test_sensors_v1 table in the realm keyspace.

Delete device data from an individual_datastreams interface

The first step consists in finding all the relevant primary keys for the device. To do so, simply run:

cqlsh:test> SELECT DISTINCT device_id, interface_id, endpoint_id, path FROM individual_datastreams
  WHERE device_id=937a0f4d-7686-1861-8618-618618618618 ALLOW FILTERING;

The output will show a set of primary keys of data belonging to your device:

 device_id                            | interface_id                         | endpoint_id                          | path
--------------------------------------|--------------------------------------|--------------------------------------|-------------
 937a0f4d-7686-1861-8618-618618618618 | c238b244-b90f-4c6d-f276-25768bf6abac | 33751412-3e77-ad1f-ad57-280cc9fad581 | /test/value
 937a0f4d-7686-1861-8618-618618618618 | 1e6fb841-9ee3-0e60-72ed-1f55b334b832 | 33751412-3e77-ad1f-ad57-280cc9fad581 | /foo/value
 ...

It is now time to perform the actual data deletion: to do so, repeat the following instruction iterating over every combination of primary keys as obtained from the output of the previous command:

cqlsh:test> DELETE FROM individual_datastreams
  WHERE device_id=937a0f4d-7686-1861-8618-618618618618
  AND interface_id=c238b244-b90f-4c6d-f276-25768bf6abac
  AND endpoint_id=33751412-3e77-ad1f-ad57-280cc9fad581
  AND path='/test/value';

Delete device data from an individual_properties interface

The first step consists in retrieving the primary keys for the device. Just run:

cqlsh:test> SELECT DISTINCT device_id, interface_id FROM individual_properties
  WHERE device_id = 937a0f4d-7686-1861-8618-618618618618 ALLOW FILTERING;

The output will be similar to the following one:

 device_id                            | interface_id
--------------------------------------+--------------------------------------
 937a0f4d-7686-1861-8618-618618618618 | c238b244-b90f-4c6d-f276-25768bf6abac
 937a0f4d-7686-1861-8618-618618618618 | 8ed086db-0bcc-5a9f-2fc2-ddf49c35e87d
 937a0f4d-7686-1861-8618-618618618618 | c61879ce-c60c-adaf-c6b4-d04b1e1b14c4

To perform the actual data deletion, run the following query for each pair of device_id and interface_id obtained from the previous query:

cqlsh:test> DELETE FROM individual_properties
  WHERE device_id = 937a0f4d-7686-1861-8618-618618618618
  AND interface_id = c238b244-b90f-4c6d-f276-25768bf6abac;

Delete device data for object datastreams

The first step consists in retrieving the primary keys for the device. For this particular example the sample interface named com.test.Sensors with major version v1 is employed. Please note that the upcoming steps must be repeated for each object datastream interface installed in your realm.

cqlsh:test> SELECT DISTINCT device_id, path FROM com_test_sensors_v1 WHERE
  device_id=937a0f4d-7686-1861-8618-618618618618 ALLOW FILTERING;

The output will show something like:

 device_id                            | path
--------------------------------------+------
 937a0f4d-7686-1861-8618-618618618618 | /foo
 ...

It is now time to perform the actual data deletion:

cqlsh:test> DELETE FROM com_test_sensors_v1
  WHERE device_id=937a0f4d-7686-1861-8618-618618618618
  AND path='/foo';

Delete device aliases

If your device has one or more aliases you will find them in the names table.

First, you have to find the primary key for the device:

cqlsh:test> SELECT object_name FROM names
  WHERE object_uuid=937a0f4d-7686-1861-8618-618618618618 ALLOW FILTERING;

If your device has any aliases, the output will show

 object_name
----------------
 my-device-alias
 ...

Thus, you can delete the alias simply executing:

cqlsh:test> DELETE FROM names WHERE object_name='my-device-alias';

Delete the device from groups

To delete the device from a device group let's find the needed keys:

SELECT group_name, insertion_uuid, device_id
  FROM grouped_devices
  WHERE device_id=937a0f4d-7686-1861-8618-618618618618
  ALLOW FILTERING;

If the device is contained in one or more groups, the output will be:

 group_name | insertion_uuid                       | device_id
------------+--------------------------------------+--------------------------------------
   my-group | c1a0dade-43bc-11ec-95be-41f7663270b3 | 937a0f4d-7686-1861-8618-618618618618
   ...

The actual deletion can be performed with:

cqlsh:test> DELETE FROM grouped_devices
  WHERE group_name='my-group'
  AND insertion_uuid=c1a0dade-43bc-11ec-95be-41f7663270b3
  AND device_id=937a0f4d-7686-1861-8618-618618618618;

Delete entries from kv_store

If your device is publishing over one or more interfaces with version v0, you will need to handle also the kv_store table.

Retrieve all the entries that must be handled:

cqlsh:test> SELECT group, key FROM kv_store WHERE key='937a0f4d-7686-1861-8618-618618618618' ALLOW
  FILTERING;

The output of the query will show something similar to

 group                                                   | key
---------------------------------------------------------+------------------------
             devices-by-interface-com.test.Sensor-v0 | k3oPTXaGGGGGGGGGGGGGGG
   devices-with-data-on-interface-com.test.Sensor-v0 | k3oPTXaGGGGGGGGGGGGGGG
   ...

To remove the entries, simply execute the following queries to remove the proper rows from the table. Please, make sure to remove all the entries referencing your device ID.

cqlsh:test> DELETE FROM kv_store
  WHERE group='devices-by-interface-com.test.Sensor-v0'
  AND key='fXBxAijfRjuJuc-ilMM90Q';

cqlsh:test> DELETE FROM kv_store
  WHERE group='devices-with-data-on-interface-com.test.Sensor-v0'
  AND key='fXBxAijfRjuJuc-ilMM90Q';

Eventually delete your device

Deleting your device from the devices table is as simple as

cqlsh:test> DELETE FROM devices WHERE device_id=937a0f4d-7686-1861-8618-618618618618;

Conclusions

If you managed to remove all the device-related entries as described in the previous sections, then your device and its data have been properly deleted from Astarte.

Before trying to reconnect your device you must make sure that the SSL certificate and all the credentials onboard your device are deleted. This is crucial for ensuring that new data published by the device can be properly ingested and processed by Astarte.


Backup your Astarte resources

Backing up your Astarte resources is crucial in all those cases when your Astarte instance has to be restored after an unforeseen event (e.g. accidental deletion of resources, deletion of the Operator - as it will be discussed later on - etc.).

A full recovery of your Astarte instance along with all the persisted data is possible if and only if your Cassandra/Scylla instance is deployed independently from Astarte, i.e. it must be deployed outside of the Astarte CR scope. Provided that this condition is met, all the data persist in the database even when Astarte is deleted from your cluster.

To restore your Astarte instance all you have to do is saving the following resources:

  • Astarte CR;
  • AstarteVoyagerIngress CR;
  • CA certificate and key;

and, assuming that the name of your Astarte is astarte and that it is deployed within the astarte namespace, it can be done simply executing the following commands:

kubectl get astarte -n astarte -o yaml > astarte-backup.yaml
kubectl get avi -n astarte -o yaml > avi-backup.yaml
kubectl get secret astarte-devices-ca -n astarte -o yaml > astarte-devices-ca-backup.yaml

Restore your backed up Astarte instance

To restore your Astarte instance simply apply the resources you saved as described here. Please, be aware that the order of the operations matters.

kubectl apply -f astarte-devices-ca-backup.yaml
kubectl apply -f astarte-backup.yaml

And when your Astarte resource is ready:

kubectl apply -f avi-backup.yaml

At the end of this step, your cluster is restored. Please, notice that the external IP of the ingress services might have changed. Take action to ensure that the changes of the IP are reflected anywhere appropriate in your deployment.


Handling Astarte when uninstalling the Operator

Installing the Astarte Operator is as simple as installing its Helm chart. Even if the install and upgrade procedures are very simple and straightforward, the design choices behind the development of the Operator must be taken into account to avoid undesired effects while handling the Operator's lifecycle.

The installation of the Operator's Helm chart is responsible for the creation of RBACs, the creation of the Operator's deployment and the installation of Astarte CRDs. The fact that all the CRDs installed with the Helm chart are templated has some important consequences: if on one hand this characteristic ensures great flexibility in configuring your Astarte instance, on the other hand it entails the possibility of deleting the CRDs by simply uninstalling the Operator.

The following sections will highlight what happens under the hood while uninstalling the Operator and show the suggested path to restore your Astarte instance after the removal of the Operator.

Please, read carefully the following sections before taking any actions on your cluster and be aware that improper operations may have catastrophic effects on your Astarte instance.

What happens when uninstalling the Operator

The Operator's installation procedure marks all the Astarte CRDs as owned by the Operator itself. Therefore, when the Operator is uninstalled all the CRDs are seen as orphaned and the Kubernetes controller automatically sets them as ready to be deleted. Thus, when the Operator is uninstalled you end up with the following situation:

  • Flow and AstarteVoyagerIngress CRDs are deleted, along with the custom resources depending on said CRDs;
  • Astarte CRD is marked for deletion, but its removal is postponed until the moment in which the Astarte finalizer is executed.

Backup your resources

Even if removing the Operator can potentially destroy your Astarte instance, there is a way to restore it avoiding any data loss. Please, refer to this dedicated section to understand how to backup your resources.

Uninstall the Operator

Once the backup of your resources is completed you can helm uninstall the Operator as explained here.

Once the Operator is deleted your Astarte instance will be marked for deletion. You can see it simply checking the Deletion timestamp field in the output of:

kubectl describe astarte -n astarte

Reinstalling the Operator

Reinstalling the Operator is crucial to have a correct management of your Astarte instance. The installation is handled simply with an helm install command as explained here.

When the first reconciliation loop is executed, the Operator becomes aware that the Astarte resource is marked for deletion, so it executes the Astarte finalizer and eventually destroys Astarte's CRD and its resources.

Even if it might look like the status of the cluster is compromised, a simple command reestablishes order:

helm upgrade --install astarte-operator astarte/astarte-operator -n kube-system

This command simply upgrades the Operator and, as a result, installs the missing CRDs. Now it is time to restore the Astarte resources.

Apply backed up resources

To restore your Astarte instance simply follow the instructions outlined here.

Conclusion

The procedure presented in the current section allows to handle the deletion of the Operator from your cluster without losing any of Astarte's data. Currently some manual intervention is required to ensure that the integrity of your instance is not compromised by the uninstall procedure.