踩坑指南：入门OpenTenBase之监控篇

yum-config-manager --add-repo http://mirrors.aliyun.com/docker-ce/linux/centos/docker-ce.repo
yum makecache

{
  "registry-mirrors": ["https://jbw52uwf.mirror.aliyuncs.com"]
}

systemctl daemon-reload
systemctl restart docker

# my 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:
    - static_configs:
        - targets:
          # - alertmanager:9093

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

# 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: ["192.168.56.10:9090"]
  # 主要修改这里，添加文件形式的扫描
  - job_name: "node"
    file_sd_configs:
    - refresh_interval: 10s
      files:
      - "/etc/prometheus/conf/node*.yaml"

- targets:
  - "ip:port"
  labels:
    hostname: pg

CREATE OR REPLACE FUNCTION __tmp_create_user() returns void as $$
BEGIN
  IF NOT EXISTS (
          SELECT                       -- SELECT list can stay empty for this
          FROM   pg_catalog.pg_user
          WHERE  usename = 'postgres_exporter') THEN
    CREATE USER postgres_exporter;
  END IF;
END;
$$ language plpgsql;

SELECT __tmp_create_user();

DROP FUNCTION __tmp_create_user();

ALTER USER postgres_exporter WITH PASSWORD 'password';

ALTER USER postgres_exporter SET SEARCH_PATH TO postgres_exporter,pg_catalog;

GRANT CONNECT ON DATABASE postgres TO postgres_exporter;

-- OpenTenBase中集成的PostgreSQL版本是10，所以可以执行以下语句，历史版本可前往开源地址进行查看。
GRANT pg_monitor to postgres_exporter;

panic: Error converting setting "session_memory_size" value "3M" to float: strconv.ParseFloat: parsing "3M": invalid syntax

goroutine 42 [running]:
main.(*pgSetting).metric(0xc000081720, 0xc0000d5c50?)
        /app/cmd/postgres_exporter/pg_setting.go:87 +0x325
main.querySettings(0x0?, 0xc00010d290)
        /app/cmd/postgres_exporter/pg_setting.go:56 +0x287
main.(*Server).Scrape(0xc00010d290, 0xc000028011?, 0x90?)
        /app/cmd/postgres_exporter/server.go:121 +0xcb
main.(*Exporter).scrapeDSN(0xc0000000c0, 0x44d406?, {0xc000028011, 0x46})
        /app/cmd/postgres_exporter/datasource.go:115 +0x1c5
main.(*Exporter).scrape(0xc0000000c0, 0x0?)
        /app/cmd/postgres_exporter/postgres_exporter.go:679 +0x16c
main.(*Exporter).Collect(0xc0000000c0, 0xc00003ff60?)
        /app/cmd/postgres_exporter/postgres_exporter.go:568 +0x25
github.com/prometheus/client_golang/prometheus.(*Registry).Gather.func1()
        /go/pkg/mod/github.com/prometheus/client_golang@v1.17.0/prometheus/registry.go:457 +0xe7
created by github.com/prometheus/client_golang/prometheus.(*Registry).Gather in goroutine 18
        /go/pkg/mod/github.com/prometheus/client_golang@v1.17.0/prometheus/registry.go:547 +0xbab

SELECT name, setting, COALESCE(unit, ''), short_desc, vartype FROM pg_settings WHERE vartype IN ('bool', 'integer', 'real') AND name != 'sync_commit_cancel_wait';