To store our data, we need the support of Cloud Storage. We can use three different data storage services—Cloud BigQuery, Cloud Bigtable, and Cloud Datastore. To store time-series, Google suggest that you use Bigtable. Bigtable is very similar to the popular open source platform Apache HBase. Bigtable is organized in tables, rows, columns, and families of columns:

• A table is a collection of rows
• A row is a collection of column families
• A column family is a collection of columns
• A column is a collection of key value pairs

In our exercise, we are going to build a schema, where a combination of device IDs and timestamps is the row key and the column families are the sensors. Please look into the layout and the content of the following table:

Before starting our deployment, we can test Bigtable locally using the GCP Bigtable emulator. To run the Bigtable emulator, we need to launch the following command:

$ gcloud beta emulators bigtable start

When the Bigtable has been started, we can execute the following command:

$ export BIGTABLE_EMULATOR_HOST=localhost:8086
$ cbt -project iiot-book-local -instance iiot-book-data createtable iiot-book-signals
$ cbt -project iiot-book-local -instance iiot-book-data createfamily iiot-book-signals signal1

The first line forces the Bigtable command-line tool cbt to use a local emulator. The second line creates a table called iiot-book-signals. The third line names our first column family signal1.

We can now store our first record as follows:

$ cbt -project iiot-book-local -instance iiot-book-data set iiot-book-signals my-iiot-device#1531639262000 signal1:value=13.0 signal1:quality='GOOD'

To read it, use the following command:

$ cbt -project iiot-book-local -instance iiot-book-data read iiot-book-signals

We can now build our Bigtable in the cloud. Follow these steps:

1. We need to create an instance from the left-hand menu of the GCP homepage:

2. Now, we can define the instance name as iiot-book-storage. Select the instance type as Development, as shown in the following screenshot:

To create the data table, we can either use the UI or the cbt script. In this exercise, we will use the cbt tool.

3. We need to open a new Command Prompt and execute the following command:

$ cbt -project iiot-book-<id> -instance iiot-book-storage createtable iiot-book-signals
% cbt -project iiot-book-<id> -instance iiot-book-storage createfamily iiot-book-signals signal1

4. Finally we can check the creation of the table with the following command:

$ cbt -project iiot-book-<id> -instance iiot-book-storage ls iiot-book-signals