「Foreign Data Wrapper / PostgreSQL」
https://decode.red/net/archives/1417

参考) https://qiita.com/Yokogawa_Ishino/items/c3467efb83e7fa342734

influxdbモジュールのインストール
環境) Ubuntu 22.04

n@n10:~$ python3 -V
Python 3.10.6
n@n10:~$ sudo apt install python3-pip
n@n10:~$ python3 -m pip install influxdb

from influxdb import InfluxDBClient
from datetime import datetime
import time
import random

db = InfluxDBClient(host='localhost', port=8086, database='sample01')

for i in range(10):
    json_body = [
        {
            "measurement": "sample_measurement",
            "time": datetime.utcnow(),
            "fields": {
                "data01": random.randint(0, 100),
                "data02": random.randint(0, 100)
            }
        }
    ]
    print("Write data: {0}".format(json_body))
    db.write_points(json_body)
    time.sleep(1)

(1秒ごとにランダムなデータを書くプログラム)

n@n10:~$ influx
Connected to http://localhost:8086 version 1.6.7~rc0
InfluxDB shell version: 1.6.7~rc0
> use sample01
Using database sample01
> select * from sample_measurement
name: sample_measurement
time data01 data02
—- —— ——
1682121753264329000 31 85
1682121754336419000 8 80
1682121755826517000 31 50
1682121756839369000 15 43
1682121757854193000 24 63
1682121758873117000 84 59
….

Grafanaの接続設定

テスト接続

データ表示

IoTデバイスのデータ取集、表示に使うと便利そうですが、単純にブログラムの出力結果にこういう使い方するのもいい感じです。

ここではSpring-bootフレームワークを使ってメトリクスデータを収集することとし、まずは下記を参考にサンプルのJava Webアプリを作成しました。
https://spring.pleiades.io/spring-boot/docs/current/reference/html/getting-started.html#getting-started.first-application

環境) Ubuntu 22.04　(192.168.1.172)

n@n10:~/spring/work01$ cat ~/.bash_profile
export JAVA_HOME=$(readlink -f /usr/bin/java | sed “s:bin/java::”)
export PATH=$PATH:/opt/apache-maven/bin
n@n10:~/spring/work01$ java -version
openjdk version “17.0.6” 2023-01-17
OpenJDK Runtime Environment (build 17.0.6+10-Ubuntu-0ubuntu122.04)
OpenJDK 64-Bit Server VM (build 17.0.6+10-Ubuntu-0ubuntu122.04, mixed mode, sharing)
n@n10:~/spring/work01$ mvn -v
Apache Maven 3.9.0 (9b58d2bad23a66be161c4664ef21ce219c2c8584)
Maven home: /opt/apache-maven
Java version: 17.0.6, vendor: Private Build, runtime: /usr/lib/jvm/java-17-openjdk-amd64
Default locale: en_US, platform encoding: UTF-8
OS name: “linux”, version: “5.15.0-67-generic”, arch: “amd64”, family: “unix”

mavenとかpomとか、いつも開発の初めに戸惑いますので、手順を残しておきます。(mavenのインストールは下記参照)
https://decode.red/net/archives/1424

spring.pleiades.ioのサイトにあるpom.xmlをベースに、Webアプリを構築するためのスタータ、メトリクスを収集するためのアクチュエータ、Prometheusとの連携するためのライブラリ、そしてjarにビルドするための設定を追加しました。(pom.xmlをエディタで作成してから、同フォルダでmvnコマンド実行)

pom.xml

<?xml version="1.0" encoding="UTF-8"?>
<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>

    <groupId>com.example</groupId>
    <artifactId>myproject</artifactId>
    <version>0.0.1-SNAPSHOT</version>

    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.0.4</version>
    </parent>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>

      <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
      </dependency>

      <dependency>
            <groupId>io.micrometer</groupId>
            <artifactId>micrometer-registry-prometheus</artifactId>
      </dependency>
    </dependencies>

   <build>
    <plugins>
      <plugin>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-maven-plugin</artifactId>
        <configuration>
          <mainClass>com.example.MyApplication</mainClass>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

src/main/resources/application.properties

debug=true
management.endpoints.enabled-by-default=true
management.endpoints.web.exposure.include=*

src/main/java/MyApplication.java　(メトリクスには無関係だが一応作成)

package com.example;

import org.springframework.boot.*;
import org.springframework.boot.autoconfigure.*;
import org.springframework.web.bind.annotation.*;

@RestController
@SpringBootApplication
public class MyApplication {

    @RequestMapping("/")
    String home() {
        return "Hello World!";
    }

    public static void main(String[] args) {
        SpringApplication.run(MyApplication.class, args);
    }

}

依存性ツリーの表示

mvn dependency:tree

サンプルプログラム(192.168.1.172:8080)を実行するサーバの起動

mvn spring-boot:run

パッケージのビルド(一応確認)

mvn install　(or mvn package)

パッケージから実行

java -jar target/myproject-0.0.1-SNAPSHOT.jar

Prometheusのインストール

参考)
https://www.server-world.info/query?os=Ubuntu_22.04&p=prometheus&f=1
https://www.server-world.info/query?os=Ubuntu_22.04&p=prometheus&f=5

sudo apt install prometheus prometheus-node-exporter
service prometheus status

/etc/prometheus/prometheus.yml にspring-bootへ接続する設定を追加

– job_name: ‘spring’
metrics_path: ‘/actuator/prometheus’
static_configs:
– targets: [‘localhost:8080’]

サービスstart確認して下記にアクセス

http://192.168.1.172:9090/classic/graph

Grafanaのインストール
参考)
https://www.server-world.info/query?os=Ubuntu_22.04&p=grafana

rootユーザで

wget -q -O /usr/share/keyrings/grafana.key https://packages.grafana.com/gpg.key
echo “deb [signed-by=/usr/share/keyrings/grafana.key] https://packages.grafana.com/oss/deb stable main” | tee -a /etc/apt/sources.list.d/grafana.list
apt update
apt install grafana

root@n10:~# service grafana-server status
○ grafana-server.service – Grafana instance
Loaded: loaded (/lib/systemd/system/grafana-server.service; disabled; vendor preset: enabled)
Active: inactive (dead)
Docs: http://docs.grafana.org

サービスstartとして下記にアクセス

http://192.168.1.172:3000/login

Prometheus画面
jvm_memory_used_bytesというメトリクスを選択

Grafana画面
prometheusとの接続

同様に、jvm_memory_used_bytesというメトリクスを選択

このようにJVMのメモリを簡単にモニタすることができました。
prometheus.ymlの設定で、spring-bootへの接続設定をしていなくても、JVM関連のメトリクスの選択項目自体は表示されますが、選択しても”no data”となります。
長くなりますが、最後にactuatorでどのようなものが出力されるのか、のこしてみました。

n@n10:~$ curl http://localhost:8080/actuator | jq
% Total % Received % Xferd Average Speed Time Time Time Current
Dload Upload Total Spent Left Speed
100 1844 0 1844 0 0 328k 0 –:–:– –:–:– –:–:– 360k

{
  "_links": {
    "self": {
      "href": "http://localhost:8080/actuator",
      "templated": false
    },
    "beans": {
      "href": "http://localhost:8080/actuator/beans",
      "templated": false
    },
    "caches-cache": {
      "href": "http://localhost:8080/actuator/caches/{cache}",
      "templated": true
    },
    "caches": {
      "href": "http://localhost:8080/actuator/caches",
      "templated": false
    },
    "health": {
      "href": "http://localhost:8080/actuator/health",
      "templated": false
    },
    "health-path": {
      "href": "http://localhost:8080/actuator/health/{*path}",
      "templated": true
    },
    "info": {
      "href": "http://localhost:8080/actuator/info",
      "templated": false
    },
    "conditions": {
      "href": "http://localhost:8080/actuator/conditions",
      "templated": false
    },
    "shutdown": {
      "href": "http://localhost:8080/actuator/shutdown",
      "templated": false
    },
    "configprops": {
      "href": "http://localhost:8080/actuator/configprops",
      "templated": false
    },
    "configprops-prefix": {
      "href": "http://localhost:8080/actuator/configprops/{prefix}",
      "templated": true
    },
    "env": {
      "href": "http://localhost:8080/actuator/env",
      "templated": false
    },
    "env-toMatch": {
      "href": "http://localhost:8080/actuator/env/{toMatch}",
      "templated": true
    },
    "loggers": {
      "href": "http://localhost:8080/actuator/loggers",
      "templated": false
    },
    "loggers-name": {
      "href": "http://localhost:8080/actuator/loggers/{name}",
      "templated": true
    },
    "heapdump": {
      "href": "http://localhost:8080/actuator/heapdump",
      "templated": false
    },
    "threaddump": {
      "href": "http://localhost:8080/actuator/threaddump",
      "templated": false
    },
    "prometheus": {
      "href": "http://localhost:8080/actuator/prometheus",
      "templated": false
    },
    "metrics-requiredMetricName": {
      "href": "http://localhost:8080/actuator/metrics/{requiredMetricName}",
      "templated": true
    },
    "metrics": {
      "href": "http://localhost:8080/actuator/metrics",
      "templated": false
    },
    "scheduledtasks": {
      "href": "http://localhost:8080/actuator/scheduledtasks",
      "templated": false
    },
    "mappings": {
      "href": "http://localhost:8080/actuator/mappings",
      "templated": false
    }
  }
}

http://192.168.1.172:8080/actuator/prometheus

# HELP jvm_memory_used_bytes The amount of used memory
# TYPE jvm_memory_used_bytes gauge
jvm_memory_used_bytes{area=”heap”,id=”G1 Survivor Space”,} 610528.0
jvm_memory_used_bytes{area=”heap”,id=”G1 Old Gen”,} 1.536768E7
jvm_memory_used_bytes{area=”nonheap”,id=”Metaspace”,} 3.053188E7
jvm_memory_used_bytes{area=”nonheap”,id=”CodeCache”,} 7017856.0
jvm_memory_used_bytes{area=”heap”,id=”G1 Eden Space”,} 1.8874368E7
jvm_memory_used_bytes{area=”nonheap”,id=”Compressed Class Space”,} 4342440.0
# HELP application_ready_time_seconds Time taken (ms) for the application to be ready to service requests
# TYPE application_ready_time_seconds gauge
application_ready_time_seconds{main_application_class=”com.example.MyApplication”,} 1.848
# HELP jvm_info JVM version info
# TYPE jvm_info gauge
jvm_info{runtime=”OpenJDK Runtime Environment”,vendor=”Private Build”,version=”17.0.6+10-Ubuntu-0ubuntu122.04″,} 1.0
# HELP jvm_gc_memory_allocated_bytes_total Incremented for an increase in the size of the (young) heap memory pool after one GC to before the next
# TYPE jvm_gc_memory_allocated_bytes_total counter
jvm_gc_memory_allocated_bytes_total 0.0
# HELP tomcat_sessions_rejected_sessions_total
# TYPE tomcat_sessions_rejected_sessions_total counter
tomcat_sessions_rejected_sessions_total 0.0
# HELP executor_active_threads The approximate number of threads that are actively executing tasks
# TYPE executor_active_threads gauge
executor_active_threads{name=”applicationTaskExecutor”,} 0.0
# HELP process_files_open_files The open file descriptor count
# TYPE process_files_open_files gauge
process_files_open_files 53.0
# HELP system_load_average_1m The sum of the number of runnable entities queued to available processors and the number of runnable entities running on the available processors averaged over a period of time
# TYPE system_load_average_1m gauge
system_load_average_1m 0.14697265625
# HELP application_started_time_seconds Time taken (ms) to start the application
# TYPE application_started_time_seconds gauge
application_started_time_seconds{main_application_class=”com.example.MyApplication”,} 1.812
# HELP disk_total_bytes Total space for path
# TYPE disk_total_bytes gauge
disk_total_bytes{path=”/home/n/spring/work01/.”,} 5.5836598272E10
# HELP process_cpu_usage The “recent cpu usage” for the Java Virtual Machine process
# TYPE process_cpu_usage gauge
process_cpu_usage 0.0
# HELP jvm_threads_live_threads The current number of live threads including both daemon and non-daemon threads
# TYPE jvm_threads_live_threads gauge
jvm_threads_live_threads 21.0
# HELP jvm_memory_usage_after_gc_percent The percentage of long-lived heap pool used after the last GC event, in the range [0..1]
# TYPE jvm_memory_usage_after_gc_percent gauge
jvm_memory_usage_after_gc_percent{area=”heap”,pool=”long-lived”,} 0.0
# HELP tomcat_sessions_created_sessions_total
# TYPE tomcat_sessions_created_sessions_total counter
tomcat_sessions_created_sessions_total 0.0
# HELP executor_pool_size_threads The current number of threads in the pool
# TYPE executor_pool_size_threads gauge
executor_pool_size_threads{name=”applicationTaskExecutor”,} 0.0
# HELP jvm_classes_unloaded_classes_total The total number of classes unloaded since the Java virtual machine has started execution
# TYPE jvm_classes_unloaded_classes_total counter
jvm_classes_unloaded_classes_total 0.0
# HELP jvm_gc_live_data_size_bytes Size of long-lived heap memory pool after reclamation
# TYPE jvm_gc_live_data_size_bytes gauge
jvm_gc_live_data_size_bytes 0.0
# HELP jvm_buffer_total_capacity_bytes An estimate of the total capacity of the buffers in this pool
# TYPE jvm_buffer_total_capacity_bytes gauge
jvm_buffer_total_capacity_bytes{id=”mapped – ‘non-volatile memory'”,} 0.0
jvm_buffer_total_capacity_bytes{id=”mapped”,} 0.0
jvm_buffer_total_capacity_bytes{id=”direct”,} 8192.0
# HELP logback_events_total Number of events that made it to the logs
# TYPE logback_events_total counter
logback_events_total{level=”warn”,} 0.0
logback_events_total{level=”debug”,} 11.0
logback_events_total{level=”error”,} 0.0
logback_events_total{level=”trace”,} 0.0
logback_events_total{level=”info”,} 5.0
# HELP tomcat_sessions_expired_sessions_total
# TYPE tomcat_sessions_expired_sessions_total counter
tomcat_sessions_expired_sessions_total 0.0
# HELP jvm_gc_max_data_size_bytes Max size of long-lived heap memory pool
# TYPE jvm_gc_max_data_size_bytes gauge
jvm_gc_max_data_size_bytes 1.251999744E9
# HELP tomcat_sessions_active_current_sessions
# TYPE tomcat_sessions_active_current_sessions gauge
tomcat_sessions_active_current_sessions 0.0
# HELP executor_queue_remaining_tasks The number of additional elements that this queue can ideally accept without blocking
# TYPE executor_queue_remaining_tasks gauge
executor_queue_remaining_tasks{name=”applicationTaskExecutor”,} 2.147483647E9
# HELP executor_queued_tasks The approximate number of tasks that are queued for execution
# TYPE executor_queued_tasks gauge
executor_queued_tasks{name=”applicationTaskExecutor”,} 0.0
# HELP jvm_gc_memory_promoted_bytes_total Count of positive increases in the size of the old generation memory pool before GC to after GC
# TYPE jvm_gc_memory_promoted_bytes_total counter
jvm_gc_memory_promoted_bytes_total 0.0
# HELP jvm_buffer_memory_used_bytes An estimate of the memory that the Java virtual machine is using for this buffer pool
# TYPE jvm_buffer_memory_used_bytes gauge
jvm_buffer_memory_used_bytes{id=”mapped – ‘non-volatile memory'”,} 0.0
jvm_buffer_memory_used_bytes{id=”mapped”,} 0.0
jvm_buffer_memory_used_bytes{id=”direct”,} 8192.0
# HELP system_cpu_usage The “recent cpu usage” of the system the application is running in
# TYPE system_cpu_usage gauge
system_cpu_usage 0.0
# HELP tomcat_sessions_alive_max_seconds
# TYPE tomcat_sessions_alive_max_seconds gauge
tomcat_sessions_alive_max_seconds 0.0
# HELP jvm_threads_peak_threads The peak live thread count since the Java virtual machine started or peak was reset
# TYPE jvm_threads_peak_threads gauge
jvm_threads_peak_threads 21.0
# HELP jvm_threads_states_threads The current number of threads
# TYPE jvm_threads_states_threads gauge
jvm_threads_states_threads{state=”runnable”,} 7.0
jvm_threads_states_threads{state=”blocked”,} 0.0
jvm_threads_states_threads{state=”waiting”,} 11.0
jvm_threads_states_threads{state=”timed-waiting”,} 3.0
jvm_threads_states_threads{state=”new”,} 0.0
jvm_threads_states_threads{state=”terminated”,} 0.0
# HELP jvm_buffer_count_buffers An estimate of the number of buffers in the pool
# TYPE jvm_buffer_count_buffers gauge
jvm_buffer_count_buffers{id=”mapped – ‘non-volatile memory'”,} 0.0
jvm_buffer_count_buffers{id=”mapped”,} 0.0
jvm_buffer_count_buffers{id=”direct”,} 1.0
# HELP tomcat_sessions_active_max_sessions
# TYPE tomcat_sessions_active_max_sessions gauge
tomcat_sessions_active_max_sessions 0.0
# HELP process_files_max_files The maximum file descriptor count
# TYPE process_files_max_files gauge
process_files_max_files 1048576.0
# HELP executor_pool_max_threads The maximum allowed number of threads in the pool
# TYPE executor_pool_max_threads gauge
executor_pool_max_threads{name=”applicationTaskExecutor”,} 2.147483647E9
# HELP system_cpu_count The number of processors available to the Java virtual machine
# TYPE system_cpu_count gauge
system_cpu_count 2.0
# HELP executor_pool_core_threads The core number of threads for the pool
# TYPE executor_pool_core_threads gauge
executor_pool_core_threads{name=”applicationTaskExecutor”,} 8.0
# HELP jvm_gc_overhead_percent An approximation of the percent of CPU time used by GC activities over the last lookback period or since monitoring began, whichever is shorter, in the range [0..1]
# TYPE jvm_gc_overhead_percent gauge
jvm_gc_overhead_percent 0.0
# HELP jvm_threads_daemon_threads The current number of live daemon threads
# TYPE jvm_threads_daemon_threads gauge
jvm_threads_daemon_threads 17.0
# HELP jvm_memory_committed_bytes The amount of memory in bytes that is committed for the Java virtual machine to use
# TYPE jvm_memory_committed_bytes gauge
jvm_memory_committed_bytes{area=”heap”,id=”G1 Survivor Space”,} 1048576.0
jvm_memory_committed_bytes{area=”heap”,id=”G1 Old Gen”,} 2.7262976E7
jvm_memory_committed_bytes{area=”nonheap”,id=”Metaspace”,} 3.11296E7
jvm_memory_committed_bytes{area=”nonheap”,id=”CodeCache”,} 7536640.0
jvm_memory_committed_bytes{area=”heap”,id=”G1 Eden Space”,} 2.4117248E7
jvm_memory_committed_bytes{area=”nonheap”,id=”Compressed Class Space”,} 4587520.0
# HELP http_server_requests_active_seconds_max
# TYPE http_server_requests_active_seconds_max gauge
http_server_requests_active_seconds_max{exception=”none”,method=”GET”,outcome=”SUCCESS”,status=”200″,uri=”UNKNOWN”,} 0.043207552
# HELP http_server_requests_active_seconds
# TYPE http_server_requests_active_seconds summary
http_server_requests_active_seconds_active_count{exception=”none”,method=”GET”,outcome=”SUCCESS”,status=”200″,uri=”UNKNOWN”,} 1.0
http_server_requests_active_seconds_duration_sum{exception=”none”,method=”GET”,outcome=”SUCCESS”,status=”200″,uri=”UNKNOWN”,} 0.043175703
# HELP executor_completed_tasks_total The approximate total number of tasks that have completed execution
# TYPE executor_completed_tasks_total counter
executor_completed_tasks_total{name=”applicationTaskExecutor”,} 0.0
# HELP jvm_memory_max_bytes The maximum amount of memory in bytes that can be used for memory management
# TYPE jvm_memory_max_bytes gauge
jvm_memory_max_bytes{area=”heap”,id=”G1 Survivor Space”,} -1.0
jvm_memory_max_bytes{area=”heap”,id=”G1 Old Gen”,} 1.251999744E9
jvm_memory_max_bytes{area=”nonheap”,id=”Metaspace”,} -1.0
jvm_memory_max_bytes{area=”nonheap”,id=”CodeCache”,} 5.0331648E7
jvm_memory_max_bytes{area=”heap”,id=”G1 Eden Space”,} -1.0
jvm_memory_max_bytes{area=”nonheap”,id=”Compressed Class Space”,} 1.073741824E9
# HELP jvm_compilation_time_ms_total The approximate accumulated elapsed time spent in compilation
# TYPE jvm_compilation_time_ms_total counter
jvm_compilation_time_ms_total{compiler=”HotSpot 64-Bit Tiered Compilers”,} 688.0
# HELP process_start_time_seconds Start time of the process since unix epoch.
# TYPE process_start_time_seconds gauge
process_start_time_seconds 1.679636917197E9
# HELP disk_free_bytes Usable space for path
# TYPE disk_free_bytes gauge
disk_free_bytes{path=”/home/n/spring/work01/.”,} 3.8974779392E10
# HELP jvm_classes_loaded_classes The number of classes that are currently loaded in the Java virtual machine
# TYPE jvm_classes_loaded_classes gauge
jvm_classes_loaded_classes 7578.0
# HELP process_uptime_seconds The uptime of the Java virtual machine
# TYPE process_uptime_seconds gauge
process_uptime_seconds 9.749