さくらのクラウドでオートスケールを検証｜CPU負荷に応じてWebサーバを自動で増減させる

dnf install httpd

mkdir -p /var/www/autoscale

vi /etc/httpd/conf.d/autoscale.conf

<VirtualHost *:80>
    ServerName example.com

    DocumentRoot /var/www/autoscale

    <Directory /var/www/autoscale>
        Require all granted
    </Directory>

    ErrorLog /var/log/httpd/autoscale_error.log
    CustomLog /var/log/httpd/autoscale_access.log combined
</VirtualHost>

vi /var/www/autoscale/index.html

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="UTF-8">
    <title>オートスケールテスト</title>
    <style>
        body {
            font-family: sans-serif;
            text-align: center;
            margin-top: 100px;
        }
    </style>
</head>
<body>
    <h1>オートスケールテスト</h1>
    <p>server: autoscale-base</p>
</body>
</html>

httpd -t

systemctl enable httpd --now

systemctl status httpd

firewall-cmd --zone=public --add-service=http --permanent

firewall-cmd --reload

resources:
  - type: ServerGroup
    name: "AutoScale-worker"
    server_name_prefix: "AutoScale-worker"
    zone: "is1c"

    parent:
      type: ELB
      selector: "AutoScale-elb"

    min_size: 0
    max_size: 1

    plans:
      - name: "minimum"
        size: 0
      - name: "maximum"
        size: 1

    setup_grace_period: 120
    shutdown_force: false

    auto_healing:
      enabled: false

    template:
      interface_driver: "virtio"

      plan:
        core: 1
        memory: 1
        dedicated_cpu: false

      network_interfaces:
        - upstream: "shared"
          expose:
            ports:
              - 80

      disks:
        - source_archive: "AutoScale-template"
          plan: "ssd"
          connection: "virtio"
          size: 20

      edit_parameter:
        disabled: false
        password: ""
        disable_pw_auth: true
        enable_dhcp: false
        change_partition_uuid: true

        ssh_keys:
          - "使用しているSSH公開鍵"

        startup_scripts:
          - |
            #!/bin/bash
            # @sacloud-once
            set -eu

            cat > /var/www/autoscale/index.html <<'HTML'
            <!DOCTYPE html>
            <html lang="ja">
            <head>
                <meta charset="UTF-8">
                <title>オートスケールテスト</title>
                <style>
                    body {
                        font-family: sans-serif;
                        text-align: center;
                        margin-top: 100px;
                    }
                </style>
            </head>
            <body>
                <h1>オートスケールテスト</h1>
                <p>server: {{ .Name }}</p>
            </body>
            </html>
            HTML

            systemctl enable httpd --now

autoscaler:
  cooldown: 300

dnf install stress-ng

stress-ng --cpu 0 --cpu-load 60

top

top - 21:21:02 up  1:43,  2 users,  load average: 0.47, 0.30, 0.11
Tasks:  94 total,   2 running,  92 sleeping,   0 stopped,   0 zombie
%Cpu0  : 59.9 us,  0.3 sy,  0.0 ni, 39.1 id,  0.0 wa,  0.3 hi,  0.3 si,  0.0 st
MiB Mem :    957.0 total,    345.5 free,    345.8 used,    432.8 buff/cache
MiB Swap:   4096.0 total,   4049.9 free,     46.1 used.    611.2 avail Mem

    PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
  21900 root      20   0   39196   7528   4260 R  59.8   0.8   0:05.19 stress-ng-cpu
    630 root      20   0  405156  18328   7216 S   0.3   1.9   0:04.35 fail2ban-server
      1 root      20   0  172692   9788   5592 S   0.0   1.0   0:01.11 systemd
      2 root      20   0       0      0      0 S   0.0   0.0   0:00.00 kthreadd
      3 root      20   0       0      0      0 S   0.0   0.0   0:00.00 pool_workqueue_
      4 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/R-rcu_gp
      5 root       0 -20       0      0      0 I   0.0   0.0   0:00.00 kworker/R-sync_wq

curl -i http://ELB_VIP/

[root@autoscale-base ~]# curl -i http://ELB_VIP/
HTTP/1.1 200 OK
date: Wed, 30 Sep 2026 12:43:10 GMT
server: Apache/2.4.62 (AlmaLinux)
last-modified: Wed, 30 Sep 2026 12:38:44 GMT
etag: "178-65cb29470e0d7"
accept-ranges: bytes
content-length: 376
content-type: text/html; charset=UTF-8
via: 1.1 sac-elb

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="UTF-8">
    <title>オートスケールテスト</title>
    <style>
        body {
            font-family: sans-serif;
            text-align: center;
            margin-top: 100px;
        }
    </style>
</head>
<body>
    <h1>オートスケールテスト</h1>
    <p>server: autoscale-base</p>
</body>
</html>
[root@autoscale-base ~]#

[root@autoscale-base ~]# curl -i http://ELB_VIP/
HTTP/1.1 200 OK
date: Wed, 30 Sep 2026 12:43:11 GMT
server: Apache/2.4.62 (AlmaLinux)
last-modified: Wed, 30 Sep 2026 12:30:15 GMT
etag: "17e-65cb2761b7548"
accept-ranges: bytes
content-length: 382
content-type: text/html; charset=UTF-8
via: 1.1 sac-elb

<!DOCTYPE html>
<html lang="ja">
<head>
    <meta charset="UTF-8">
    <title>オートスケールテスト</title>
    <style>
        body {
            font-family: sans-serif;
            text-align: center;
            margin-top: 100px;
        }
    </style>
</head>
<body>
    <h1>オートスケールテスト</h1>
    <p>server: AutoScale-worker-001</p>
</body>
</html>
[root@autoscale-base ~]#

<p>server: autoscale-base</p>

<p>server: AutoScale-worker-001</p>