Blazer

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

Try it out

Blazer 2.0 was recently released! See instructions for upgrading.

🍊 Battle-tested at Instacart

• Multiple data sources - PostgreSQL, MySQL, Redshift, and many more
• 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
• Queries
• Charts
• Dashboards
• Checks

Add this line to your application’s Gemfile:

gem 'blazer'

Run:

rails generate blazer:install
rails 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.

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

config.action_mailer.default_url_options = {host: "blazer.dokkuapp.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

For Slack notifications, create an incoming webhook and set:

BLAZER_SLACK_WEBHOOK_URL=https://hooks.slack.com/...

Name the webhook “Blazer” and add a cool icon.

Don’t forget to protect the dashboard in production.

Set the following variables in your environment or an initializer.

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

authenticate :user, ->(user) { user.admin? } do
  mount Blazer::Engine, at: "blazer"
end

Specify a before_action method to run in blazer.yml.

before_action_method: require_admin

You can define this method in your ApplicationController.

def require_admin
  # depending on your auth, something like...
  redirect_to root_path unless current_user && current_user.admin?
end

Be sure to render or redirect for unauthorized users.

Blazer runs each query in a transaction and rolls it back to prevent queries from modifying data. As an additional line of defense, we recommend using a read only user.

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;

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;

Create a user with read only permissions:

db.createUser({user: "blazer", pwd: "password", roles: ["read"]})

Also, make sure authorization is enabled when you start the server.

If your database contains sensitive or personal data, check out Hypershield to shield it.

If you need to search encrypted data, use blind indexing.

You can have Blazer transform specific variables with: [master]

Blazer.transform_variable = lambda do |name, value|
  value = User.compute_email_bidx(value) if name == "email_bidx"
  value
end

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}

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.

You can also use an array or hash for static data and enums.

smart_variables:
  period: ["day", "week", "month"]
  status: {0: "Active", 1: "Archived"}

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: "https://www.infosniper.net/index.php?ip_address={value}"

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}"

You can also use a hash for static data and enums.

smart_columns:
  status: {0: "Active", 1: "Archived"}

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.

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

Note: The order of columns matters.

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

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 - Example

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

2 columns - both numeric - Example

SELECT x, y FROM table

2 columns - string, numeric - and last column named pie - Example

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

Columns named latitude and longitude or lat and lon or lat and lng - Example

SELECT name, latitude, longitude FROM cities

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

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

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

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 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.

Blazer supports two different approaches to anomaly detection.

Trend is easiest to set up but uses an external service.

Add trend to your Gemfile:

gem 'trend'

And add to config/blazer.yml:

anomaly_checks: trend

R is harder to set up but doesn’t use an external service. It uses Twitter’s AnomalyDetection library.

First, install R. Then, run:

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

And add to config/blazer.yml:

anomaly_checks: r

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

If you’re on Heroku, follow these additional instructions.

Blazer has experimental support for forecasting through Trend.

Example

Add trend to your Gemfile:

gem 'trend'

And add to config/blazer.yml:

forecasting: trend

A forecast link will appear for queries that return 2 columns with types timestamp and numeric.

Blazer supports multiple data sources 🎉

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"] %>
    # ...

• Amazon Athena
• Amazon Redshift
• Apache Drill
• Cassandra
• Druid
• Elasticsearch
• Google BigQuery
• IBM DB2 and Informix
• MongoDB
• MySQL
• Oracle
• PostgreSQL
• Presto
• Snowflake
• SQLite
• SQL Server

You can also create an adapter for any other data store.

Note: In the examples below, we recommend using environment variables for urls.

data_sources:
  my_source:
    url: <%= ENV["BLAZER_MY_SOURCE_URL"] %>

Add aws-sdk-athena and aws-sdk-glue to your Gemfile and set:

data_sources:
  my_source:
    adapter: athena
    database: database
    output_location: s3://some-bucket/

Add activerecord4-redshift-adapter or activerecord5-redshift-adapter to your Gemfile and set:

data_sources:
  my_source:
    url: redshift://user:password@hostname:5439/database

Add drill-sergeant to your Gemfile and set:

data_sources:
  my_source:
    adapter: drill
    url: http://hostname:8047

Add cassandra-driver to your Gemfile and set:

data_sources:
  my_source:
    url: cassandra://user:password@hostname:9042/keyspace

First, enable SQL support on the broker.

Set:

data_sources:
  my_source:
    adapter: druid
    url: http://hostname:8082

Add elasticsearch and elasticsearch-xpack to your Gemfile and set:

data_sources:
  my_source:
    adapter: elasticsearch
    url: http://user:password@hostname:9200

Add google-cloud-bigquery to your Gemfile and set:

data_sources:
  my_source:
    adapter: bigquery
    project: your-project
    keyfile: path/to/keyfile.json

Use ibm_db.

Add mongo to your Gemfile and set:

data_sources:
  my_source:
    url: mongodb://user:password@hostname:27017/database

Add mysql2 to your Gemfile (if it’s not there) and set:

data_sources:
  my_source:
    url: mysql2://user:password@hostname:3306/database

Use activerecord-oracle_enhanced-adapter.

Add pg to your Gemfile (if it’s not there) and set:

data_sources:
  my_source:
    url: postgres://user:password@hostname:5432/database

Add presto-client to your Gemfile and set:

data_sources:
  my_source:
    url: presto://user@hostname:8080/catalog

First, install the ODBC driver. Add odbc_adapter to your Gemfile and set:

data_sources:
  my_source:
    adapter: snowflake
    dsn: ProductionSnowflake

Add sqlite3 to your Gemfile and set:

data_sources:
  my_source:
    url: sqlite3:path/to/database.sqlite3

Add tiny_tds and activerecord-sqlserver-adapter to your Gemfile and set:

data_sources:
  my_source:
    url: sqlserver://user:password@hostname:1433/database

Create an adapter for any data store with:

class FooAdapter < Blazer::Adapters::BaseAdapter
  # code goes here
end

Blazer.register_adapter "foo", FooAdapter

See the Presto adapter for a good example. Then use:

data_sources:
  my_source:
    adapter: foo
    url: http://user:password@hostname:9200/

Blazer supports a basic permissions model.

1. Queries without a name are unlisted
2. Queries whose name starts with # are only listed to the creator
3. Queries whose name starts with * can only be edited by the creator

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

• Khan Academy
• Codecademy

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

Looking for a standalone version? Check out Ghost Blazer.

By default, queries take up a request while they are running. To run queries asynchronously, add to your config:

async: true

Note: Requires Rails 5+ and caching to be enabled. If you have multiple web processes, your app must use a centralized cache store like Memcached or Redis.

config.cache_store = :mem_cache_store

Add the R buildpack to your app.

heroku buildpacks:add --index 1 https://github.com/virtualstaticvoid/heroku-buildpack-r.git\#cedar-14

And create an init.r with:

if (!"AnomalyDetection" %in% installed.packages()) {
  install.packages("devtools")
  devtools::install_github("twitter/AnomalyDetection")
}

Commit and deploy away. The first deploy may take a few minutes.

If views are stuck with a Loading... message, there might be a problem with strict CSP settings in your app. This can be checked with Firefox or Chrome dev tools. You can allow Blazer to override these settings for its controllers with:

override_csp: true

To use Slack notifications, create a migration

rails g migration add_slack_channels_to_blazer_checks

with:

add_column :blazer_checks, :slack_channels, :text

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")

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"

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:

rails 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 current user
# user_method: current_user

# method name for the display name
# user_name: name

# email to send checks from
# from_email: blazer@example.org

View the changelog

Blazer uses a number of awesome open source projects, including Rails, Vue.js, jQuery, Bootstrap, Selectize, StickyTableHeaders, Stupid jQuery Table Sort, and Date Range Picker.

Demo data from MovieLens.

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.