Blazer

Explore your data with SQL. Easily create charts and dashboards, and share them with your team.

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Features

Multiple data sources - works with PostgreSQL, MySQL, and Redshift
Variables - run the same queries with different values
Checks & alerts - get emailed when bad data appears
Audits - all queries are tracked
Security - works with your authentication system

Installation

Add this line to your application’s Gemfile:

gem 'blazer'

Run:

rails g blazer:install
rake db:migrate

And mount the dashboard in your config/routes.rb:

mount Blazer::Engine, at: "blazer"

For production, specify your database:

ENV["BLAZER_DATABASE_URL"] = "postgres://user:password@hostname:5432/database"

Blazer tries to protect against queries which modify data (by running each query in a transaction and rolling it back), but a safer approach is to use a read only user. See how to create one.

Checks (optional)

Be sure to set a host in config/environments/production.rb for emails to work.

config.action_mailer.default_url_options = {host: "blazerme.herokuapp.com"}

Schedule checks to run (with cron, Heroku Scheduler, etc). The default options are every 5 minutes, 1 hour, or 1 day, which you can customize. For each of these options, set up a task to run.

rake blazer:run_checks SCHEDULE="5 minutes"
rake blazer:run_checks SCHEDULE="1 hour"
rake blazer:run_checks SCHEDULE="1 day"

You can also set up failing checks to be sent once a day (or whatever you prefer).

rake blazer:send_failing_checks

Here’s what it looks like with cron.

*/5 * * * * rake blazer:run_checks SCHEDULE="5 minutes"
0   * * * * rake blazer:run_checks SCHEDULE="1 hour"
30  7 * * * rake blazer:run_checks SCHEDULE="1 day"
0   8 * * * rake blazer:send_failing_checks

Permissions

PostgreSQL

Create a user with read only permissions:

BEGIN;
CREATE ROLE blazer LOGIN PASSWORD 'secret123';
GRANT CONNECT ON DATABASE database_name TO blazer;
GRANT USAGE ON SCHEMA public TO blazer;
GRANT SELECT ON ALL TABLES IN SCHEMA public TO blazer;
ALTER DEFAULT PRIVILEGES IN SCHEMA public GRANT SELECT ON TABLES TO blazer;
COMMIT;

MySQL

Create a user with read only permissions:

GRANT SELECT, SHOW VIEW ON database_name.* TO blazer@’127.0.0.1′ IDENTIFIED BY ‘secret123‘;
FLUSH PRIVILEGES;

Sensitive Data

To protect sensitive info like password hashes and access tokens, use views. Documentation coming soon.

Authentication

Don’t forget to protect the dashboard in production.

Basic Authentication

Set the following variables in your environment or an initializer.

ENV["BLAZER_USERNAME"] = "andrew"
ENV["BLAZER_PASSWORD"] = "secret"

Devise

authenticate :user, lambda { |user| user.admin? } do
  mount Blazer::Engine, at: "blazer"
end

Other

Specify a before_action method to run in blazer.yml.

before_action: require_admin

Queries

Variables

Create queries with variables.

SELECT * FROM users WHERE gender = {gender}

Use {start_time} and {end_time} for time ranges. Example

SELECT * FROM ratings WHERE rated_at >= {start_time} AND rated_at <= {end_time}

Smart Variables

Example

Suppose you have the query:

SELECT * FROM users WHERE occupation_id = {occupation_id}

Instead of remembering each occupation’s id, users can select occupations by name.

Add a smart variable with:

smart_variables:
  occupation_id: "SELECT id, name FROM occupations ORDER BY name ASC"

The first column is the value of the variable, and the second column is the label.

Linked Columns

Example - title column

Link results to other pages in your apps or around the web. Specify a column name and where it should link to. You can use the value of the result with {value}.

linked_columns:
  user_id: "/admin/users/{value}"
  ip_address: "http://www.infosniper.net/index.php?ip_address={value}"

Smart Columns

Example - occupation_id column

Suppose you have the query:

SELECT name, city_id FROM users

See which city the user belongs to without a join.

smart_columns:
  city_id: "SELECT id, name FROM cities WHERE id IN {value}"

Caching

Blazer can automatically cache results to improve speed. It can cache slow queries:

cache:
  mode: slow
  expires_in: 60 # min
  slow_threshold: 15 # sec

Or it can cache all queries:

cache:
  mode: all
  expires_in: 60 # min

Of course, you can force a refresh at any time.

Charts

Blazer will automatically generate charts based on the types of the columns returned in your query.

Line Chart

There are two ways to generate line charts.

2+ columns - timestamp, numeric(s) - Example

SELECT date_trunc('week', created_at), COUNT(*) FROM users GROUP BY 1

3 columns - timestamp, string, numeric - Example

SELECT date_trunc('week', created_at), gender, COUNT(*) FROM users GROUP BY 1, 2

Column Chart

There are also two ways to generate column charts.

2+ columns - string, numeric(s) - Example

SELECT gender, COUNT(*) FROM users GROUP BY 1

3 columns - string, string, numeric

SELECT gender, zip_code, COUNT(*) FROM users GROUP BY 1, 2

Maps

Columns named latitude and longitude or lat and lon - Example

SELECT name, latitude, longitude FROM cities

To enable, get an access token from Mapbox and set ENV["MAPBOX_ACCESS_TOKEN"].

Targets

Use the column name target to draw a line for goals.

SELECT date_trunc('week', created_at), COUNT(*) AS new_users, 100000 AS target FROM users GROUP BY 1

Dashboards

Create a dashboard with multiple queries. Example

If the query has a chart, the chart is shown. Otherwise, you’ll see a table.

If any queries have variables, they will show up on the dashboard.

Checks

Checks give you a centralized place to see the health of your data. Example

Create a query to identify bad rows.

SELECT * FROM ratings WHERE user_id IS NULL /* all ratings should have a user */

Then create check with optional emails if you want to be notified. Emails are sent when a check starts failing, and when it starts passing again.

Anomaly Detection

Anomaly detection is supported thanks to Twitter’s AnomalyDetection library.

First, install R. Then, run:

install.packages("devtools")
devtools::install_github("twitter/AnomalyDetection")

And add to config/blazer.yml:

anomaly_checks: true

If upgrading from version 1.4 or below, also follow the upgrade instructions.

Data Sources

Blazer supports multiple data sources :tada:

Add additional data sources in config/blazer.yml:

data_sources:
  main:
    url: <%= ENV["BLAZER_DATABASE_URL"] %>
    # timeout, smart_variables, linked_columns, smart_columns
  catalog:
    url: <%= ENV["CATALOG_DATABASE_URL"] %>
    # ...
  redshift:
    url: <%= ENV["REDSHIFT_DATABASE_URL"] %>
    # ...

Redshift

Add activerecord4-redshift-adapter to your Gemfile and set:

ENV["BLAZER_DATABASE_URL"] = "redshift://user:password@hostname:5439/database"

Learn SQL

Have team members who want to learn SQL? Here are a few great, free resources.

Useful Tools

For an easy way to group by day, week, month, and more with correct time zones, check out Groupdate.

Upgrading

1.5

To take advantage of the anomaly detection, create a migration

rails g migration upgrade_blazer_to_1_5

with:

add_column(:blazer_checks, :check_type, :string)
add_column(:blazer_checks, :message, :text)
commit_db_transaction

Blazer::Check.reset_column_information

Blazer::Check.where(invert: true).update_all(check_type: "missing_data")
Blazer::Check.where(check_type: nil).update_all(check_type: "bad_data")

1.3

To take advantage of the latest features, create a migration

rails g migration upgrade_blazer_to_1_3

with:

add_column :blazer_dashboards, :creator_id, :integer
add_column :blazer_checks, :creator_id, :integer
add_column :blazer_checks, :invert, :boolean
add_column :blazer_checks, :schedule, :string
add_column :blazer_checks, :last_run_at, :timestamp
commit_db_transaction

Blazer::Check.update_all schedule: "1 hour"

1.0

Blazer 1.0 brings a number of new features:

multiple data sources, including Redshift
dashboards
checks

To upgrade, run:

bundle update blazer

Create a migration

rails g migration upgrade_blazer_to_1_0

with:

add_column :blazer_queries, :data_source, :string
add_column :blazer_audits, :data_source, :string

create_table :blazer_dashboards do |t|
  t.text :name
  t.timestamps
end

create_table :blazer_dashboard_queries do |t|
  t.references :dashboard
  t.references :query
  t.integer :position
  t.timestamps
end

create_table :blazer_checks do |t|
  t.references :query
  t.string :state
  t.text :emails
  t.timestamps
end

And run:

rake db:migrate

Update config/blazer.yml with:

# see https://github.com/ankane/blazer for more info

data_sources:
  main:
    url: <%= ENV["BLAZER_DATABASE_URL"] %>

    # statement timeout, in seconds
    # applies to PostgreSQL only
    # none by default
    # timeout: 15

    # time to cache results, in minutes
    # can greatly improve speed
    # none by default
    # cache: 60

    # wrap queries in a transaction for safety
    # not necessary if you use a read-only user
    # true by default
    # use_transaction: false

    smart_variables:
      # zone_id: "SELECT id, name FROM zones ORDER BY name ASC"

    linked_columns:
      # user_id: "/admin/users/{value}"

    smart_columns:
      # user_id: "SELECT id, name FROM users WHERE id IN {value}"

# create audits
audit: true

# change the time zone
# time_zone: "Pacific Time (US & Canada)"

# class name of the user model
# user_class: User

# method name for the user model
# user_name: name

# email to send checks from
# from_email: [email protected]

TODO

advanced permissions
standalone version
better navigation

History

View the changelog

Thanks

Blazer uses a number of awesome, open source projects.

Created by ankane and righi

Demo data from MovieLens.

Want to Make Blazer Better?

That’s awesome! Here are a few ways you can help:

Report bugs
Fix bugs and submit pull requests
Write, clarify, or fix documentation
Suggest or add new features

Check out the dev app to get started.