No errors/info at logs, when `probe_success 0`

[KES777]

What did you do?

version: '3.8'

services:
  postgres-exporter:
    image: quay.io/prometheuscommunity/postgres-exporter:master
    command: [
      "--config.file", "/etc/postgres-exporter.yml",
      "--log.level", "debug",
      "--disable-default-metrics",
    ]
    volumes:
      - ${STACK_ROOT}/postgres-exporter.yml:/etc/postgres-exporter.yml
    environment:
      DATA_SOURCE_NAME: "postgresql://postgres:xxx@db:5432/postgres?sslmode=disable,postgresql://postgres:password@tsdb:5432/postgres?sslmode=disable"
      PG_EXPORTER_AUTO_DISCOVER_DATABASES: "false"
      PG_EXPORTER_EXCLUDE_DATABASES: "template0,template1"
      PG_EXPORTER_CONSTANT_LABELS: "dbcluster=pgdb"

# cat postgres-exporter.yml 
auth_modules:
  pgdb:
    type: userpass
    userpass:
      username: postgres
      password: xxx
    options:
      # options become key=value parameters of the DSN
      sslmode: disable

  tsdb:
    type: userpass
    userpass:
      username: postgres
      password: password
    options:
      # options become key=value parameters of the DSN
      sslmode: disable

What did you expect to see?
I expect some errors are reported.

What did you see instead? Under which circumstances?
I do not see any errors at logs.

Environment

• System information: Docker compose
• postgres_exporter version: 0.12.0
• postgres_exporter flags:

"--config.file", "/etc/postgres-exporter.yml",
"--log.level", "debug",
"--disable-default-metrics",

When I did the query:
http://host:9187/probe?target=tsdb:5432&auth_module=tsdd

auth_module tsdd not found

This is expected, because tsdd was not configured.

http://host:9187/probe?target=xxtsdb:5432&auth_module=tsdb
I see this output:

# HELP pg_scrape_collector_duration_seconds postgres_exporter: Duration of a collector scrape.
# TYPE pg_scrape_collector_duration_seconds gauge
pg_scrape_collector_duration_seconds{collector="bgwriter"} 0.011608647
pg_scrape_collector_duration_seconds{collector="database"} 0.010288506
# HELP pg_scrape_collector_success postgres_exporter: Whether a collector succeeded.
# TYPE pg_scrape_collector_success gauge
pg_scrape_collector_success{collector="bgwriter"} 0
pg_scrape_collector_success{collector="database"} 0
# HELP probe_duration_seconds Returns how long the probe took to complete in seconds
# TYPE probe_duration_seconds gauge
probe_duration_seconds 5.5028e-05
# HELP probe_success Displays whether or not the probe was a success
# TYPE probe_success gauge
probe_success 0

I expect here some error instead of prometheus metrics. Or, at least, some errors at log file.
There should be error that xxtsdb:5432 does not exists/not configured/no connection.

When I query:
http://172.22.22.15:9187/probe?target=tsdb:5432/postgres&auth_module=tsdb
or
http://172.22.22.15:9187/probe?target=tsdb:5432&auth_module=tsdb

# HELP pg_database_size_bytes Disk space used by the database
# TYPE pg_database_size_bytes gauge
pg_database_size_bytes{datname="postgres"} 1.637802787e+09
pg_database_size_bytes{datname="template0"} 8.602115e+06
pg_database_size_bytes{datname="template1"} 1.1125251e+07
# HELP pg_scrape_collector_duration_seconds postgres_exporter: Duration of a collector scrape.
# TYPE pg_scrape_collector_duration_seconds gauge
pg_scrape_collector_duration_seconds{collector="bgwriter"} 0.331756757
pg_scrape_collector_duration_seconds{collector="database"} 0.275337993
# HELP pg_scrape_collector_success postgres_exporter: Whether a collector succeeded.
# TYPE pg_scrape_collector_success gauge
pg_scrape_collector_success{collector="bgwriter"} 1
pg_scrape_collector_success{collector="database"} 1
# HELP pg_stat_bgwriter_buffers_alloc_total Number of buffers allocated
# TYPE pg_stat_bgwriter_buffers_alloc_total counter
pg_stat_bgwriter_buffers_alloc_total 506044
# HELP pg_stat_bgwriter_buffers_backend_fsync_total Number of times a backend had to execute its own fsync call (normally the background writer handles those even when the backend does its own write)
# TYPE pg_stat_bgwriter_buffers_backend_fsync_total counter
pg_stat_bgwriter_buffers_backend_fsync_total 0
# HELP pg_stat_bgwriter_buffers_backend_total Number of buffers written directly by a backend
# TYPE pg_stat_bgwriter_buffers_backend_total counter
pg_stat_bgwriter_buffers_backend_total 469537
# HELP pg_stat_bgwriter_buffers_checkpoint_total Number of buffers written during checkpoints
# TYPE pg_stat_bgwriter_buffers_checkpoint_total counter
pg_stat_bgwriter_buffers_checkpoint_total 1.639138e+06
# HELP pg_stat_bgwriter_buffers_clean_total Number of buffers written by the background writer
# TYPE pg_stat_bgwriter_buffers_clean_total counter
pg_stat_bgwriter_buffers_clean_total 0
# HELP pg_stat_bgwriter_checkpoint_sync_time_total Total amount of time that has been spent in the portion of checkpoint processing where files are synchronized to disk, in milliseconds
# TYPE pg_stat_bgwriter_checkpoint_sync_time_total counter
pg_stat_bgwriter_checkpoint_sync_time_total 40829
# HELP pg_stat_bgwriter_checkpoint_write_time_total Total amount of time that has been spent in the portion of checkpoint processing where files are written to disk, in milliseconds
# TYPE pg_stat_bgwriter_checkpoint_write_time_total counter
pg_stat_bgwriter_checkpoint_write_time_total 9.4221717e+07
# HELP pg_stat_bgwriter_checkpoints_req_total Number of requested checkpoints that have been performed
# TYPE pg_stat_bgwriter_checkpoints_req_total counter
pg_stat_bgwriter_checkpoints_req_total 1
# HELP pg_stat_bgwriter_checkpoints_timed_total Number of scheduled checkpoints that have been performed
# TYPE pg_stat_bgwriter_checkpoints_timed_total counter
pg_stat_bgwriter_checkpoints_timed_total 118
# HELP pg_stat_bgwriter_maxwritten_clean_total Number of times the background writer stopped a cleaning scan because it had written too many buffers
# TYPE pg_stat_bgwriter_maxwritten_clean_total counter
pg_stat_bgwriter_maxwritten_clean_total 0
# HELP pg_stat_bgwriter_stats_reset_total Time at which these statistics were last reset
# TYPE pg_stat_bgwriter_stats_reset_total counter
pg_stat_bgwriter_stats_reset_total 1.666883095e+09
# HELP probe_duration_seconds Returns how long the probe took to complete in seconds
# TYPE probe_duration_seconds gauge
probe_duration_seconds 0.000113717
# HELP probe_success Displays whether or not the probe was a success
# TYPE probe_success gauge
probe_success 0

Still probe_success 0 and no any reports about errors at log file =(

[KES777]

Also there is no any errors when I provide incorrect database name cc:
http://172.22.22.15:9187/probe?target=db:5432/cc&auth_module=pgdb

# HELP pg_scrape_collector_duration_seconds postgres_exporter: Duration of a collector scrape.
# TYPE pg_scrape_collector_duration_seconds gauge
pg_scrape_collector_duration_seconds{collector="bgwriter"} 0.028025201
pg_scrape_collector_duration_seconds{collector="database"} 0.046365659
# HELP pg_scrape_collector_success postgres_exporter: Whether a collector succeeded.
# TYPE pg_scrape_collector_success gauge
pg_scrape_collector_success{collector="bgwriter"} 0
pg_scrape_collector_success{collector="database"} 0
# HELP probe_duration_seconds Returns how long the probe took to complete in seconds
# TYPE probe_duration_seconds gauge
probe_duration_seconds 0.000192409
# HELP probe_success Displays whether or not the probe was a success
# TYPE probe_success gauge
probe_success 0

probe_success 0 is not informative. I expect to see something at container log, at least GET /probe...

[kjbass]

I could be completely off base, but I believe the probe_sucess field is actually never set to success. Take a peek at this code here. Potentially worthy of a new issue in its own right, though.

[sysadmind]

The probe_success field should be set now. This should be resolved with #724

[KES777]

@sysadmind Hi, thanks for improvement. But I do not see any informative messages at logs after that fix =(