Bool Operator does not work as expected

[toninis]

Bug Report

What did you do?
Tried to bool compare two vectors.
Vector 1

count by (container_env_monitored_environment_name) (container_last_seen{job="dcos-docker-metrics",container_env_driver_type="engine"})

which has output:

{container_env_monitored_environment_name="value1"} | 1
{container_env_monitored_environment_name="value2"} | 1
{container_env_monitored_environment_name="value3"} | 1
{container_env_monitored_environment_name="value4"} | 1

Vector 2

count by (container_env_monitored_environment_name) (container_last_seen{job="dcos-docker-metrics",container_env_driver_type="riskevolution"})  

which has output:

{container_env_monitored_environment_name="value1"} | 1
{container_env_monitored_environment_name="value2"} | 1

So I compared the two vectors with the bool option:

count by (container_env_monitored_environment_name) (container_last_seen{job="dcos-docker-metrics",container_env_driver_type="engine"}) == bool count by (container_env_monitored_environment_name) (container_last_seen{job="dcos-docker-metrics",container_env_driver_type="riskevolution"})  

What did you expect to see?
Based on docs here :

Comparison operators are defined between scalar/scalar, vector/scalar, and vector/vector value pairs. By default they filter. Their behavior can be modified by providing bool after the operator, which will return 0 or 1 for the value rather than filtering.

Shouldn't the result of this operation using the bool option to keep the ones unmached and provide the output below.

{container_env_monitored_environment_name="value4"} | 0
{container_env_monitored_environment_name="value2"} | 1
{container_env_monitored_environment_name="value3"} | 0
{container_env_monitored_environment_name="value1"} | 1

What did you see instead? Under which circumstances?
Instead the expected results get filtered out as below. Is this the corect behaviour ?
What am I missing ?

{container_env_monitored_environment_name="value1"} | 1
{container_env_monitored_environment_name="value2"} | 1

Environment

• System information:
  Linux 4.15.0-1031-aws x86_64
• Docker Info

Client:
 Version:           18.09.1
 API version:       1.39
 Go version:        go1.10.6
 Git commit:        4c52b90
 Built:             Wed Jan  9 19:35:31 2019
 OS/Arch:           linux/amd64
 Experimental:      false

Server: Docker Engine - Community
 Engine:
  Version:          18.09.1
  API version:      1.39 (minimum version 1.12)
  Go version:       go1.10.6
  Git commit:       4c52b90
  Built:            Wed Jan  9 19:02:44 2019
  OS/Arch:          linux/amd64
  Experimental:     false

• Prometheus version:

prometheus, version 2.6.1 (branch: HEAD, revision: b639fe140c1f71b2cbad3fc322b17efe60839e7e)
  build user:       root@4c0e286fe2b3
  build date:       20190115-19:12:04
  go version:       go1.11.4

• Alertmanager version:

alertmanager, version 0.15.3 (branch: HEAD, revision: d4a7697cc90f8bce62efe7c44b63b542578ec0a1)
  build user:       root@4ecc17c53d26
  build date:       20181109-15:40:48
  go version:       go1.11.2

• Prometheus configuration file:

# global config
global:
  scrape_interval:     15s # Set the scrape interval to every 15 seconds. Default is every 1 minute.
  evaluation_interval: 15s # Evaluate rules every 15 seconds. The default is every 1 minute.
  # scrape_timeout is set to the global default (10s).

# Alertmanager configuration
alerting:
  alertmanagers:
  - scheme: http
    static_configs:
    - targets:
      - alertmanager:9093


# Load rules once and periodically evaluate them according to the global 'evaluation_interval'.
rule_files:
  - "alert.rules"

# A scrape configuration containing exactly one endpoint to scrape:
# Here it's Prometheus itself.
scrape_configs:
  # The job name is added as a label `job=<job_name>` to any timeseries scraped from this config.
  - job_name: 'prometheus'

    # metrics_path defaults to '/metrics'
    # scheme defaults to 'http'.

    static_configs:
    - targets: ['localhost:9090']

  # EC2 Jobs
  - job_name: 'mss-production-nodes'
    ec2_sd_configs:
      - region: eu-west-1
        access_key: *******
        secret_key: *******
        port: 9100
    relabel_configs:
      - source_labels: [__meta_ec2_tag_Monitored]
        regex: PrometheusProduction.*
        action: keep
      - source_labels: [__meta_ec2_tag_privateurl]
        regex:  '(.*)'
        target_label: __address__
        replacement: '${1}:9100'
      - source_labels: [__meta_ec2_tag_Name]
        regex:  '(.*)'
        target_label: hostname
        replacement: '${1}'
  - job_name: 'mss-production-nodes-services'
    ec2_sd_configs:
      - region: eu-west-1
        access_key: ******
        secret_key: ******
        port: 9265
    relabel_configs:
      - source_labels: [__meta_ec2_tag_Monitored]
        regex: PrometheusProduction.*
        action: keep
      - source_labels: [__meta_ec2_private_ip]
        regex:  '(.*)'
        target_label: __address__
        replacement: '${1}:9256'
      - source_labels: [__meta_ec2_tag_Name]
        regex:  '(.*)'
        target_label: hostname
        replacement: '${1}'
  - job_name: 'dcos-cluster-nodes'
    ec2_sd_configs:
      - region: eu-west-1
        access_key: *****
        secret_key: *******
        port: 9100
    relabel_configs:
      - source_labels: [__meta_ec2_tag_Monitored]
        regex: DCOSProduction.*
        action: keep
      - source_labels: [__meta_ec2_tag_privateurl]
        regex:  '(.*)'
        target_label: __address__
        replacement: '${1}:9100'
      - source_labels: [__meta_ec2_tag_Name]
        regex:  '(.*)'
        target_label: hostname
        replacement: '${1}'
  - job_name: 'elastic-node-monitoring'
    ec2_sd_configs:
      - region: eu-west-1
        access_key: *****
        secret_key: ******
    relabel_configs:
      - source_labels: [__meta_ec2_tag_Monitored]
        regex: ElasticProduction.*
        action: keep
      - source_labels: [__meta_ec2_tag_privateurl]
        regex:  '(.*)'
        target_label: __address__
        replacement: '${1}:9100'
      - source_labels: [__meta_ec2_tag_Name]
        regex:  '(.*)'
        target_label: hostname
        replacement: '${1}'
  - job_name: 'elasticsearch'
    metrics_path: "/_prometheus/metrics"
    ec2_sd_configs:
      - region: eu-west-1
        access_key: ****
        secret_key: ******      
    relabel_configs:
      - source_labels: [__meta_ec2_tag_Monitored]
        regex: ElasticProduction.*
        action: keep
      - source_labels: [__meta_ec2_private_ip]
        regex:  '(.*)'
        target_label: __address__
        replacement: '${1}:9200'
      - source_labels: [__meta_ec2_tag_Name]
        regex:  '(.*)'
        target_label: hostname
        replacement: '${1}'
  - job_name: 'dcos-docker-metrics'
    ec2_sd_configs:
      - region: eu-west-1
        access_key: ****
        secret_key: ***
    relabel_configs:
      - source_labels: [__meta_ec2_tag_Monitored]
        regex: DCOSProduction.*
        action: keep
      - source_labels: [__meta_ec2_tag_privateurl]
        regex:  '(.*)'
        target_label: __address__
        replacement: '${1}:11256'
      - source_labels: [__meta_ec2_tag_Name]
        regex:  '(.*)'
        target_label: hostname
        replacement: '${1}'
    metric_relabel_configs:
      - source_labels: [container_label_MESOS_TASK_ID]
        regex:  '(.*)\.(.*)'
        target_label: mesos_service_name
        replacement: '${1}'
      - source_labels: [container_env_spark_executor_opts]
        regex:  '-DCLIENT_NAME=(.*) -DEXECUTOR_TYPE=(.*)'
        target_label: container_env_monitored_environment_name
        replacement: '${1}'
      - source_labels: [container_env_spark_executor_opts]
        regex:  '-DCLIENT_NAME=(.*) -DEXECUTOR_TYPE=(.*)'
        target_label: container_env_executor_type
        replacement: '${2}'

• Alertmanager configuration file:

global:
  resolve_timeout: 3m
  slack_api_url: *****************
templates:
- '/etc/alertmanager/templates/*.tmpl'
receivers:
- name: slack
  slack_configs:
  - api_url: ****************
    channel: '#******'
    send_resolved: true
  email_configs:
  - to: ********************
    from: *************************
    smarthost: ***********************
    auth_username: ********************
    auth_password: ****************
    send_resolved: true

route:
  group_by:
  - alertname
  - cluster
  - service
  group_interval: 2m
  group_wait: 30s
  receiver: slack
  repeat_interval: 4h

[brian-brazil]

Normal matching behaviour is what's happening here, try with values other than 1 and you'll see what's happening.

It makes more sense to ask questions like this on the prometheus-users mailing list rather than in a GitHub issue. On the mailing list, more people are available to potentially respond to your question, and the whole community can benefit from the answers provided.