以下是一个场景，必须在 3 节点集群中对 Mariadb 进行配置更改。我编辑了配置文件，然后使用以下命令关闭了节点：
# service mysqld stop
在其他 2 个节点上进行了更改并执行了相同的操作。当我使用
# galera_new_cluster
已开始
在网络节点上启动，启动正常。最后一个节点是我进行更改的第一个节点。
此节点无法启动。它遇到服务启动超时并死机。我在故障节点或主节点上找不到任何错误。我确实将超时时间从默认的 90 秒调整为 2 小时，但同样超时了。
只是寻找一些可能发生的事情的线索。
现在 galera 配置失败：
[galera]
# Mandatory settings
binlog_format=ROW
default-storage-engine=innodb
innodb_autoinc_lock_mode=2
bind-address=192.168.10.238
wsrep_on=ON
wsrep_provider=/usr/lib64/galera/libgalera_smm.so
wsrep_cluster_address="gcomm://192.168.10.200,192.168.10.201"
## Galera Cluster Configuration
wsrep_cluster_name="Cluster1"
## Galera Synchronization Configuration
wsrep_sst_method=rsync
## Galera Node Configuration
wsrep_node_address="192.168.10.238"
wsrep_node_name="db3"
启动超时消息：
# service mysql start
Starting mysql (via systemctl): Job for mariadb.service failed because a timeout was exceeded. See "systemctl status mariadb.service" and "journalctl -xe" for details.
[FAILED]
在主节点上，我看到最后一个节点成功加入集群：
2018-03-13 9:08:36 140261636175616 [Note] WSREP: (050b87ee, 'tcp://0.0.0.0:4567') connection established to ce802915 tcp://192.168.10.238:4567
2018-03-13 9:08:36 140261636175616 [Note] WSREP: (050b87ee, 'tcp://0.0.0.0:4567') turning message relay requesting on, nonlive peers:
2018-03-13 9:08:36 140261636175616 [Note] WSREP: declaring 8ee7874f at tcp://192.168.10.201:4567 stable
2018-03-13 9:08:36 140261636175616 [Note] WSREP: declaring ce802915 at tcp://192.168.10.238:4567 stable
2018-03-13 9:08:36 140261636175616 [Note] WSREP: Node 050b87ee state prim
2018-03-13 9:08:36 140261636175616 [Note] WSREP: view(view_id(PRIM,050b87ee,87) memb {
050b87ee,0
8ee7874f,0
ce802915,0
} joined {
} left {
} partitioned {
})
2018-03-13 9:08:36 140261636175616 [Note] WSREP: save pc into disk
2018-03-13 9:08:36 140261627782912 [Note] WSREP: New COMPONENT: primary = yes, bootstrap = no, my_idx = 0, memb_num = 3
2018-03-13 9:08:36 140261627782912 [Note] WSREP: STATE_EXCHANGE: sent state UUID: a3fa8cd5-26bf-11e8-8f00-a686a9b10fbd
2018-03-13 9:08:36 140261627782912 [Note] WSREP: STATE EXCHANGE: sent state msg: a3fa8cd5-26bf-11e8-8f00-a686a9b10fbd
2018-03-13 9:08:36 140261627782912 [Note] WSREP: STATE EXCHANGE: got state msg: a3fa8cd5-26bf-11e8-8f00-a686a9b10fbd from 0 (b1)
2018-03-13 9:08:36 140261627782912 [Note] WSREP: STATE EXCHANGE: got state msg: a3fa8cd5-26bf-11e8-8f00-a686a9b10fbd from 1 (db2)
2018-03-13 9:08:36 140261627782912 [Note] WSREP: STATE EXCHANGE: got state msg: a3fa8cd5-26bf-11e8-8f00-a686a9b10fbd from 2 (db3)
2018-03-13 9:08:36 140261627782912 [Note] WSREP: Quorum results:
version = 4,
component = PRIMARY,
conf_id = 20,
members = 2/3 (joined/total),
act_id = 3166274,
last_appl. = 3166245,
protocols = 0/7/3 (gcs/repl/appl),
group UUID = 4687a061-0310-11e8-a49f-534404044853
2018-03-13 9:08:36 140261627782912 [Note] WSREP: Flow-control interval: [28, 28]
2018-03-13 9:08:36 140261627782912 [Note] WSREP: Trying to continue unpaused monitor
2018-03-13 9:08:36 140261931068160 [Note] WSREP: New cluster view: global state: 4687a061-0310-11e8-a49f-534404044853:3166274, view# 21: Primary, number of nodes: 3, my index: 0, protocol version 3
2018-03-13 9:08:36 140261931068160 [Note] WSREP: wsrep_notify_cmd is not defined, skipping notification.
2018-03-13 9:08:36 140261931068160 [Note] WSREP: REPL Protocols: 7 (3, 2)
2018-03-13 9:08:36 140261931068160 [Note] WSREP: Assign initial position for certification: 3166274, protocol version: 3
2018-03-13 9:08:36 140261686085376 [Note] WSREP: Service thread queue flushed.
2018-03-13 9:08:39 140261636175616 [Note] WSREP: (050b87ee, 'tcp://0.0.0.0:4567') turning message relay requesting off
当 Mariadb 尝试在故障主机上启动时，我没有看到任何错误：
Mar 13 09:11:43 pn09 systemd: Starting MariaDB 10.1.30 database server...
Mar 13 09:11:49 pn09 sh: WSREP: Recovered position 4687a061-0310-11e8-a49f-534404044853:2564462
Mar 13 09:11:49 pn09 mysqld: 2018-03-13 9:11:49 122545243265280 [Note] /usr/sbin/mysqld (mysqld 10.1.30-MariaDB) starting as process 7558 ...
Mar 13 09:11:50 pn09 rsyncd[7667]: rsyncd version 3.0.9 starting, listening on port 4444
我对这个问题有点困惑，任何指导都值得感激。我不明白为什么在单个节点上停止和启动服务会出现问题。其他两个我可以干净利落地启动和关闭，没有任何问题。
需要注意的一点是，在深入研究这个问题时，我注意到 grastate.dat 文件中所有 3 个节点的 SEQNO 都设置为 -1。不确定为什么会发生这种情况，不知道这是不是关键问题。
其他关注点——服务启动失败后，一些后台进程仍在运行：
# ps aux |grep mysql
mysql 7558 0.2 0.3 349912 57920 ? Ssl 09:11 0:00 /usr/sbin/mysqld --wsrep_start_position=4687a061-0310-11e8-a49f-534404044853:2564462
mysql 7567 1.2 0.0 113388 1796 ? S 09:11 0:03 /bin/bash -ue /usr//bin/wsrep_sst_rsync --role joiner --address 192.168.10.238 --datadir /var/lib/mysql/ --parent 7558
mysql 7667 0.0 0.0 114652 1068 ? S 09:11 0:00 rsync --daemon --no-detach --port 4444 --config /var/lib/mysql//rsync_sst.conf