Ceph Storage Cluster Progressive Delivery

Ceph Storage Cluster Progressive Delivery คืออะไร

Ceph เป็น open source distributed storage system ที่รองรับ Object Storage (S3-compatible), Block Storage (RBD) และ File System (CephFS) ในระบบเดียว Progressive Delivery คือการ deploy changes แบบค่อยๆ เปิดให้ผู้ใช้ทีละกลุ่ม ลดความเสี่ยงจาก bad deployments รวมถึง canary releases, blue-green deployments และ feature flags การรวมสองแนวคิดนี้ช่วยให้ upgrade Ceph clusters ได้อย่างปลอดภัย ลด downtime และป้องกัน data loss จาก faulty updates

Ceph Architecture Overview

# ceph_arch.py — Ceph architecture overview

import json



class CephArchitecture:

    COMPONENTS = {

        "mon": {

            "name": "Ceph Monitor (MON)",

            "description": "รักษา cluster map — track สถานะ OSD, PG, CRUSH map",

            "count": "อย่างน้อย 3 (odd number สำหรับ quorum)",

            "upgrade_risk": "สูง — ถ้า majority down = cluster unavailable",

        },

        "osd": {

            "name": "Ceph OSD (Object Storage Daemon)",

            "description": "เก็บข้อมูลจริง — 1 OSD ต่อ 1 disk/SSD",

            "count": "ขึ้นกับ capacity — ทั่วไป 10-1000+",

            "upgrade_risk": "ปานกลาง — upgrade ทีละ OSD, data replicated",

        },

        "mgr": {

            "name": "Ceph Manager (MGR)",

            "description": "Dashboard, monitoring, orchestration",

            "count": "2 (active-standby)",

            "upgrade_risk": "ต่ำ — standby takeover อัตโนมัติ",

        },

        "mds": {

            "name": "Metadata Server (MDS)",

            "description": "จัดการ metadata สำหรับ CephFS",

            "count": "1-2 active + standby",

            "upgrade_risk": "ปานกลาง — CephFS unavailable ชั่วคราว",

        },

        "rgw": {

            "name": "RADOS Gateway (RGW)",

            "description": "S3/Swift compatible object storage API",

            "count": "2+ behind load balancer",

            "upgrade_risk": "ต่ำ — load balancer route around upgrading instance",

        },

    }



    def show_components(self):

        print("=== Ceph Components ===\n")

        for key, comp in self.COMPONENTS.items():

            print(f"[{comp['name']}]")

            print(f"  {comp['description']}")

            print(f"  Upgrade risk: {comp['upgrade_risk']}")

            print()



arch = CephArchitecture()

arch.show_components()

Progressive Delivery Strategies

# progressive.py — Progressive delivery for Ceph

import json



class ProgressiveDelivery:

    STRATEGIES = {

        "rolling_upgrade": {

            "name": "1. Rolling Upgrade (ทีละ daemon)",

            "description": "Upgrade Ceph daemons ทีละตัว — MON → MGR → OSD → MDS → RGW",

            "steps": [

                "1. Set noout flag (ป้องกัน rebalance ขณะ upgrade)",

                "2. Upgrade MON ทีละตัว (รอ quorum กลับก่อนทำตัวถัดไป)",

                "3. Upgrade MGR (active → standby → switch)",

                "4. Upgrade OSD ทีละกลุ่ม (ทีละ rack/host)",

                "5. Upgrade MDS + RGW",

                "6. Unset noout flag",

            ],

            "risk": "ต่ำ — ทีละตัว, rollback ได้ทันที",

        },

        "canary_osd": {

            "name": "2. Canary OSD Upgrade",

            "description": "Upgrade OSD กลุ่มเล็กก่อน (1-2 hosts) → monitor → ค่อยขยาย",

            "steps": [

                "1. เลือก canary hosts (1-2 hosts ที่มี non-critical data)",

                "2. Upgrade OSDs บน canary hosts",

                "3. Monitor 24-48 ชั่วโมง: I/O latency, error rate, recovery",

                "4. ถ้า OK → upgrade batch ถัดไป (25% → 50% → 100%)",

                "5. ถ้ามีปัญหา → rollback canary hosts",

            ],

            "risk": "ต่ำมาก — impact แค่ canary hosts",

        },

        "blue_green_rgw": {

            "name": "3. Blue-Green RGW Deployment",

            "description": "Deploy RGW version ใหม่คู่กับเก่า → switch traffic ที่ load balancer",

            "steps": [

                "1. Deploy new RGW instances (green) คู่กับ existing (blue)",

                "2. Route 10% traffic ไป green",

                "3. Monitor: S3 API latency, error rate, compatibility",

                "4. Gradually increase: 10% → 25% → 50% → 100%",

                "5. Decommission blue instances",

            ],

            "risk": "ต่ำ — rollback = switch traffic กลับ blue",

        },

    }



    def show_strategies(self):

        print("=== Progressive Delivery Strategies ===\n")

        for key, strat in self.STRATEGIES.items():

            print(f"[{strat['name']}]")

            print(f"  {strat['description']}")

            print(f"  Risk: {strat['risk']}")

            for step in strat["steps"][:4]:

                print(f"    {step}")

            print()



pd = ProgressiveDelivery()

pd.show_strategies()

Automation Scripts

# automation.py — Ceph upgrade automation

import json

import random



class CephUpgradeAutomation:

    CODE = """

# ceph_upgrade.py — Automated progressive Ceph upgrade

import subprocess

import time

import json



class CephUpgrader:

    def __init__(self, target_version):

        self.target_version = target_version

        self.cluster_status = None

    

    def get_health(self):

        result = subprocess.run(

            ['ceph', 'health', '--format=json'],

            capture_output=True, text=True

        )

        return json.loads(result.stdout)

    

    def wait_healthy(self, timeout=600):

        start = time.time()

        while time.time() - start < timeout:

            health = self.get_health()

            if health.get('status') == 'HEALTH_OK':

                return True

            print(f"  Waiting for HEALTH_OK... ({health.get('status')})")

            time.sleep(30)

        return False

    

    def set_noout(self):

        subprocess.run(['ceph', 'osd', 'set', 'noout'])

        print("Set noout flag")

    

    def unset_noout(self):

        subprocess.run(['ceph', 'osd', 'unset', 'noout'])

        print("Unset noout flag")

    

    def upgrade_mon(self, host):

        print(f"Upgrading MON on {host}...")

        subprocess.run(['ssh', host, f'apt install -y ceph-mon={self.target_version}'])

        subprocess.run(['ssh', host, 'systemctl restart ceph-mon.target'])

        time.sleep(30)

        return self.wait_healthy(300)

    

    def upgrade_osd_host(self, host):

        print(f"Upgrading OSDs on {host}...")

        # Get OSDs on this host

        result = subprocess.run(

            ['ceph', 'osd', 'tree', '--format=json'],

            capture_output=True, text=True

        )

        tree = json.loads(result.stdout)

        

        # Upgrade package

        subprocess.run(['ssh', host, f'apt install -y ceph-osd={self.target_version}'])

        

        # Restart OSDs one by one

        for osd in self._get_osds_on_host(host, tree):

            subprocess.run(['ssh', host, f'systemctl restart ceph-osd@{osd}'])

            time.sleep(10)

        

        return self.wait_healthy(600)

    

    def progressive_upgrade(self, hosts, batch_pct=[10, 25, 50, 100]):

        self.set_noout()

        

        for pct in batch_pct:

            n = max(1, len(hosts) * pct // 100)

            batch = hosts[:n]

            print(f"\\n=== Batch: {pct}% ({n}/{len(hosts)} hosts) ===")

            

            for host in batch:

                success = self.upgrade_osd_host(host)

                if not success:

                    print(f"FAILED on {host}! Stopping.")

                    self.unset_noout()

                    return False

            

            print(f"Batch {pct}% complete. Monitoring...")

            time.sleep(3600)  # Monitor 1 hour

        

        self.unset_noout()

        return True



upgrader = CephUpgrader("18.2.1")

# upgrader.progressive_upgrade(osd_hosts, [10, 25, 50, 100])

"""



    def show_code(self):

        print("=== Upgrade Automation ===")

        print(self.CODE[:600])



    def upgrade_dashboard(self):

        print(f"\n=== Upgrade Progress Dashboard ===")

        phases = [

            {"phase": "MON upgrade", "status": "Complete", "hosts": "3/3"},

            {"phase": "MGR upgrade", "status": "Complete", "hosts": "2/2"},

            {"phase": "OSD canary (10%)", "status": "Complete", "hosts": "3/30"},

            {"phase": "OSD batch 2 (25%)", "status": "In Progress", "hosts": "5/8"},

            {"phase": "OSD batch 3 (50%)", "status": "Pending", "hosts": "0/15"},

            {"phase": "OSD batch 4 (100%)", "status": "Pending", "hosts": "0/30"},

        ]

        for p in phases:

            print(f"  [{p['status']:>12}] {p['phase']:<25} Hosts: {p['hosts']}")



auto = CephUpgradeAutomation()

auto.show_code()

auto.upgrade_dashboard()

Health Monitoring

# monitoring.py — Ceph health monitoring during upgrade

import json

import random



class CephMonitoring:

    HEALTH_CHECKS = {

        "cluster_health": "ceph health detail — ตรวจ HEALTH_OK/WARN/ERR",

        "osd_status": "ceph osd tree — ดู OSD up/down status",

        "pg_status": "ceph pg stat — ดู PG states (active+clean = ดี)",

        "io_stats": "ceph osd pool stats — ดู read/write IOPS per pool",

        "recovery": "ceph -s — ดู recovery/rebalance progress",

        "slow_ops": "ceph daemon osd.X perf dump — ดู slow operations",

    }



    ALERT_THRESHOLDS = {

        "osd_latency_p99": {"threshold": "50ms", "action": "Pause upgrade, investigate"},

        "pg_not_clean": {"threshold": "> 0 for 30min", "action": "Wait for PGs to clean"},

        "recovery_rate": {"threshold": "< 100MB/s", "action": "Check network, disk I/O"},

        "osd_down": {"threshold": "> 0 unexpected", "action": "Investigate, rollback if needed"},

        "cluster_health": {"threshold": "HEALTH_ERR", "action": "Stop upgrade immediately"},

    }



    def show_checks(self):

        print("=== Health Checks ===\n")

        for check, cmd in self.HEALTH_CHECKS.items():

            print(f"  [{check}] {cmd}")



    def show_alerts(self):

        print(f"\n=== Alert Thresholds ===")

        for metric, alert in self.ALERT_THRESHOLDS.items():

            print(f"  [{metric}] Threshold: {alert['threshold']} → {alert['action']}")



    def live_dashboard(self):

        print(f"\n=== Live Cluster Status ===")

        print(f"  Health: HEALTH_OK")

        print(f"  OSDs: {random.randint(28, 30)}/30 up")

        print(f"  PGs: {random.randint(250, 256)} active+clean / 256 total")

        print(f"  Read IOPS: {random.randint(1000, 5000):,}")

        print(f"  Write IOPS: {random.randint(500, 3000):,}")

        print(f"  Latency P99: {random.uniform(5, 30):.1f}ms")

        print(f"  Recovery: {random.uniform(0, 500):.0f} MB/s")

        print(f"  Capacity: {random.uniform(40, 80):.1f}% used")



mon = CephMonitoring()

mon.show_checks()

mon.show_alerts()

mon.live_dashboard()

Rollback Procedures

# rollback.py — Ceph rollback procedures import json class RollbackProcedures: ROLLBACK_STEPS = { "osd_rollback": { "name": "OSD Rollback", "steps": [ "1. ceph osd set noout (ป้องกัน rebalance)", "2. ssh systemctl stop ceph-osd.target", "3. ssh apt install ceph-osd=", "4. ssh systemctl start ceph-osd.target", "5. ceph -s (verify HEALTH_OK)", "6. Repeat สำหรับ hosts ที่ upgrade แล้ว", "7. ceph osd unset noout", ], "time": "5-15 นาทีต่อ host", }, "mon_rollback": { "name": "MON Rollback", "steps": [ "1. Stop upgraded MON: systemctl stop ceph-mon@", "2. Downgrade package: apt install ceph-mon=", "3. Start MON: systemctl start ceph-mon@", "4. Verify quorum: ceph mon stat", "5. Repeat ทีละตัว — รักษา quorum ตลอด", ], "time": "2-5 นาทีต่อ MON", }, "full_rollback": { "name": "Full Cluster Rollback", "steps": [ "1. ceph osd set noout && ceph osd set norebalance", "2. Rollback RGW → MDS → OSD → MGR → MON (reverse order)", "3. Verify cluster health after each component", "4. Unset flags: ceph osd unset noout && ceph osd unset norebalance", "5. Monitor 24 hours", ], "time": "30 นาที - 2 ชั่วโมง (ขึ้นกับ cluster size)", }, } def show_rollback(self): print("=== Rollback Procedures ===\n") for key, rb in self.ROLLBACK_STEPS.items(): print(f"[{rb['name']}] Time: {rb['time']}") for step in rb["steps"][:4]: print(f" {step}") print() def decision_matrix(self): print("=== Rollback Decision Matrix ===") decisions = [ {"condition": "1 OSD failed to start", "action": "Rollback that OSD only"}, {"condition": "Multiple OSDs slow", "action": "Pause upgrade, investigate, rollback batch"}, {"condition": "MON quorum lost", "action": "Emergency: rollback MON immediately"}, {"condition": "Data corruption detected", "action": "Full cluster rollback + data verification"}, {"condition": "Performance degraded < 20%", "action": "Monitor, may be temporary"}, ] for d in decisions: print(f" [{d['condition']}] → {d['action']}") rb = RollbackProcedures() rb.show_rollback() rb.decision_matrix()

FAQ - คำถามที่พบบ่อย

Q: Upgrade Ceph ต้อง downtime ไหม?

A: ไม่จำเป็น — ใช้ rolling upgrade ไม่มี downtime (ถ้าทำถูกต้อง) Key: upgrade ทีละ daemon, รักษา quorum (MON), data replication (OSD) set noout flag ป้องกัน unnecessary rebalance ขณะ upgrade I/O อาจช้าลงเล็กน้อยระหว่าง upgrade — แต่ไม่ down

เนื้อหาเกี่ยวข้อง — ทำความเข้าใจ stop-loss military — ข้อมูลครบถ้วน 2026

Q: Progressive delivery จำเป็นไหมสำหรับ Ceph?

แนะนำเพิ่มเติม — XM Signal

A: จำเป็นมาก เพราะ: Ceph เก็บข้อมูลสำคัญ — ถ้า upgrade ผิดพลาดอาจ data loss Bad upgrade อาจ impact ทั้ง cluster — ถ้า upgrade ทีเดียว ไม่มีทางรู้ก่อน Progressive (canary → batch) ช่วย detect ปัญหาก่อน impact ทั้ง cluster Rollback ง่ายกว่า เมื่อ upgrade แค่บางส่วน

เนื้อหาเกี่ยวข้อง — ups express คือ — คู่มือฉบับสมบูรณ์ 2026

Q: Upgrade order สำคัญไหม?

A: สำคัญมาก ลำดับที่ถูกต้อง: 1) MON (cluster map) 2) MGR (dashboard/orchestration) 3) OSD (storage daemons) 4) MDS (CephFS metadata) 5) RGW (S3 gateway) ถ้า upgrade ผิดลำดับอาจเกิด compatibility issues ระหว่าง versions

แนะนำเพิ่มเติม — หนังสือเทรดที่ SiamCafeBook

เนื้อหาเกี่ยวข้อง — ทำความเข้าใจ Terraform Module High Availability HA Setup

Q: Monitor อะไรระหว่าง upgrade?

A: Critical: ceph health (ต้อง OK/WARN), PG states (ต้อง active+clean), OSD up count Performance: I/O latency, IOPS, throughput, recovery rate Alert: HEALTH_ERR, OSD down unexpected, PG stuck, slow ops ใช้ Prometheus + Grafana dashboard สำหรับ real-time monitoring

เนื้อหาเกี่ยวข้อง — ดูเพิ่มเติมเรื่อง Vue Nuxt Server IoT Gateway