Ceph实验室：第四课：Ceph监控

本课程演示如何监控一个Ceph集群。我们将学习如何用ceph的命令行 工具 进行监控。

监控集群的整体状态

• 健康状态

ceph命令的health选项查看集群的健康状态。

# ceph health detail 

HEALTH_WARN clock skew detected on mon.ceph-node2; Monitor clock skew detected 
mon.ceph-node2 addr 192.168.1.121:6789/0 clock skew 0.194536s > max 0.05s (latency 0.00103766s)

HEALTH_WARN表示集群处于“告警”状态。

• 集群事件监控

ceph命令的－w选项用于监控集群的事件，这个命令会实时显示集群中所有的事件消息。

# ceph -w    

    cluster b6e0c604-c9dd-4eac-9b00-45ff246d64fb  
     health HEALTH_WARN  
            clock skew detected on mon.ceph-node2  
            Monitor clock skew detected   
    monmap e2: 2 mons at {ceph-node1=192.168.1.120:6789/0,ceph-node2=192.168.1.121:6789/0}  
            election epoch 24, quorum 0,1 ceph-node1,ceph-node2  
    osdmap e28: 6 osds: 6 up, 6 in  
             flags sortbitwise,require_jewel_osds  
     pgmap v99: 0 pgs, 0 pools, 0 bytes data, 0 objects  
            197 MB used, 91895 MB / 92093 MB avail    
 2017-03-16 12:00:00.000245 mon.0 [INF] HEALTH_WARN; clock skew detected on mon.ceph-node2; Monitor clock skew detected

• 集群存储空间统计

ceph命令的df选项可以获取集群的存储空间使用统计数据，包括集群的总容量，剩余的可用容量，以及已使用容量的百分百。

# ceph df    

GLOBAL:
    SIZE       AVAIL      RAW USED     %RAW USED 
    92093M     91895M         197M          0.21 
POOLS:
    NAME     ID     USED     %USED     MAX AVAIL     OBJECTS

• 集群状态

使用status选项可以查看集群的状态。

# ceph -s    

    cluster b6e0c604-c9dd-4eac-9b00-45ff246d64fb
     health HEALTH_WARN
            clock skew detected on mon.ceph-node2
            Monitor clock skew detected 
     monmap e2: 2 mons at {ceph-node1=192.168.1.120:6789/0,ceph-node2=192.168.1.121:6789/0}
            election epoch 24, quorum 0,1 ceph-node1,ceph-node2
     osdmap e28: 6 osds: 6 up, 6 in
            flags sortbitwise,require_jewel_osds
      pgmap v99: 0 pgs, 0 pools, 0 bytes data, 0 objects
            197 MB used, 91895 MB / 92093 MB avail
# ntpdate pool.ntp.org
17 Mar 04:18:56 ntpdate[20268]: adjust time server 61.216.153.106 offset 0.000257 sec
# ceph -s

    cluster b6e0c604-c9dd-4eac-9b00-45ff246d64fb
     health HEALTH_OK
     monmap e2: 2 mons at {ceph-node1=192.168.1.120:6789/0,ceph-node2=192.168.1.121:6789/0}
            election epoch 26, quorum 0,1 ceph-node1,ceph-node2
     osdmap e30: 6 osds: 6 up, 6 in
            flags sortbitwise,require_jewel_osds
      pgmap v106: 0 pgs, 0 pools, 0 bytes data, 0 objects
            198 MB used, 91895 MB / 92093 MB avail

监控monitor

• 查看MON状态

使用ceph命令的mon stat或者mon dump子命令来查看monitor的状态和map信息。

# ceph mon stat    

e2: 2 mons at {ceph-node1=192.168.1.120:6789/0,ceph-node2=192.168.1.121:6789/0}, election epoch 26, quorum 0,1 ceph-node1,ceph-node2

# ceph mon dump    
dumped monmap epoch 2
epoch 2
fsid b6e0c604-c9dd-4eac-9b00-45ff246d64fb
last_changed 2017-03-16 10:10:30.700537
created 2017-03-16 09:56:25.645057
0: 192.168.1.120:6789/0 mon.ceph-node1
1: 192.168.1.121:6789/0 mon.ceph-node2

• 查看MON的仲裁状态

在IO操作中，客户端会首先尝试与仲裁中的Leader Mon建立连接。如果leader不可用，客户端会以此尝试连接其他的mon。

# ceph quorum_status -f json-pretty    

{
    "election_epoch": 26,
    "quorum": [
        0,
        1
    ],
    "quorum_names": [
        "ceph-node1",
        "ceph-node2"
    ],
    "quorum_leader_name": "ceph-node1",
    "monmap": {
        "epoch": 2,
        "fsid": "b6e0c604-c9dd-4eac-9b00-45ff246d64fb",
        "modified": "2017-03-16 10:10:30.700537",
        "created": "2017-03-16 09:56:25.645057",
        "mons": [
            {
                "rank": 0,
                "name": "ceph-node1",
                "addr": "192.168.1.120:6789\/0"
            },
            {
                "rank": 1,
                "name": "ceph-node2",
                "addr": "192.168.1.121:6789\/0"
            }
        ]
    }
}

监控OSD

• OSD tree

OSD tree会显示每个节点上所有OSD及其在CRUSH map中的位置。

# ceph osd tree

ID WEIGHT  TYPE NAME           UP/DOWN REWEIGHT PRIMARY-AFFINITY 
-1 0.08752 root default                                          
-2 0.04376     host ceph-node1                                   
 0 0.01459         osd.0            up  1.00000          1.00000 
 1 0.01459         osd.1            up  1.00000          1.00000 
 2 0.01459         osd.2            up  1.00000          1.00000 
-3 0.04376     host ceph-node2                                   
 3 0.01459         osd.3            up  1.00000          1.00000 
 4 0.01459         osd.4            up  1.00000          1.00000 
 5 0.01459         osd.5            up  1.00000          1.00000

• 查看CRUSH map

# ceph osd crush rule list

[
    "replicated_ruleset"
]

# ceph osd crush rule dump "replicated_ruleset"

{
    "rule_id": 0,
    "rule_name": "replicated_ruleset",
    "ruleset": 0,
    "type": 1,
    "min_size": 1,
    "max_size": 10,
    "steps": [
        {
            "op": "take",
            "item": -1,
            "item_name": "default"
        },
        {
            "op": "chooseleaf_firstn",
            "num": 0,
            "type": "host"
        },
        {
            "op": "emit"
        }
    ]
}

• 监控PG

# ceph pg stat

v107: 0 pgs: ; 0 bytes data, 198 MB used, 91895 MB / 92093 MB avail