节点从集群中移除的状态

show status like '%wsrep%';

wsrep_cluster_status为Disconnected则表示该节点已经不在集群中了，示例如下

> show status like '%wsrep%';+--------------------------+----------------------+| Variable_name            | Value                |+--------------------------+----------------------+| wsrep_cluster_conf_id    | 18446744073709551615 || wsrep_cluster_size       | 0                    || wsrep_cluster_state_uuid |                      || wsrep_cluster_status     | Disconnected         || wsrep_connected          | OFF                  || wsrep_local_bf_aborts    | 0                    || wsrep_local_index        | 18446744073709551615 || wsrep_provider_name      |                      || wsrep_provider_vendor    |                      || wsrep_provider_version   |                      || wsrep_ready              | ON                   |+--------------------------+----------------------+11 rows in set (0.00 sec)

正常的集群节点状态

>show status like '%wsrep%';+----------------------------------+-----------------------------------------------------+| Variable_name                    | Value                                               |+----------------------------------+-----------------------------------------------------+| wsrep_local_state_uuid           | 5a290219-fcfc-11e8-b8b9-13c62e5c16f1                || wsrep_protocol_version           | 8                                                   || wsrep_last_applied               | 6611991575                                          || wsrep_last_committed             | 6611991589                                          || wsrep_replicated                 | 524590452                                           || wsrep_replicated_bytes           | 1094596990048                                       || wsrep_repl_keys                  | 5967904705                                          || wsrep_repl_keys_bytes            | 60340440512                                         || wsrep_repl_data_bytes            | 998666384164                                        || wsrep_repl_other_bytes           | 0                                                   || wsrep_received                   | 3695397                                             || wsrep_received_bytes             | 29564596                                            || wsrep_local_commits              | 524590438                                           || wsrep_local_cert_failures        | 0                                                   || wsrep_local_replays              | 0                                                   || wsrep_local_send_queue           | 0                                                   || wsrep_local_send_queue_max       | 66                                                  || wsrep_local_send_queue_min       | 0                                                   || wsrep_local_send_queue_avg       | 2.321160                                            || wsrep_local_recv_queue           | 0                                                   || wsrep_local_recv_queue_max       | 3                                                   || wsrep_local_recv_queue_min       | 0                                                   || wsrep_local_recv_queue_avg       | 0.000160                                            || wsrep_local_cached_downto        | 6605892261                                          || wsrep_flow_control_paused_ns     | 173078420690665                                     || wsrep_flow_control_paused        | 0.164600                                            || wsrep_flow_control_sent          | 0                                                   || wsrep_flow_control_recv          | 2806150                                             || wsrep_flow_control_interval      | [ 141, 141 ]                                        || wsrep_flow_control_interval_low  | 141                                                 || wsrep_flow_control_interval_high | 141                                                 || wsrep_flow_control_status        | OFF                                                 || wsrep_cert_deps_distance         | 418.873157                                          || wsrep_apply_oooe                 | 0.723585                                            || wsrep_apply_oool                 | 0.047621                                            || wsrep_apply_window               | 3.941686                                            || wsrep_commit_oooe                | 0.000000                                            || wsrep_commit_oool                | 0.000000                                            || wsrep_commit_window              | 1.047392                                            || wsrep_local_state                | 4                                                   || wsrep_local_state_comment        | Synced                                              || wsrep_cert_index_size            | 468                                                 || wsrep_cert_bucket_count          | 520252                                              || wsrep_gcache_pool_size           | 4294968600                                          || wsrep_causal_reads               | 0                                                   || wsrep_cert_interval              | 9.885857                                            || wsrep_ist_receive_status         |                                                     || wsrep_ist_receive_seqno_start    | 0                                                   || wsrep_ist_receive_seqno_current  | 0                                                   || wsrep_ist_receive_seqno_end      | 0                                                   || wsrep_incoming_addresses         | 10.*.*.*:3306,10.*.*.*:3306             || wsrep_desync_count               | 0                                                   || wsrep_evs_delayed                |                                                     || wsrep_evs_evict_list             |                                                     || wsrep_evs_repl_latency           | 0.000125601/0.000556424/0.00157762/0.000167964/6997 || wsrep_evs_state                  | OPERATIONAL                                         || wsrep_gcomm_uuid                 | e52417ca-fcf6-11e8-ad11-12b1aba37990                || wsrep_cluster_conf_id            | 4                                                   || wsrep_cluster_size               | 2                                                   || wsrep_cluster_state_uuid         | 5a290219-fcfc-11e8-b8b9-13c62e5c16f1                || wsrep_cluster_status             | Primary                                             || wsrep_connected                  | ON                                                  || wsrep_local_bf_aborts            | 0                                                   || wsrep_local_index                | 1                                                   || wsrep_provider_name              | Galera                                              || wsrep_provider_vendor            | Codership Oy 
     
                         || wsrep_provider_version           | 3.26(rac090bc)                                      || wsrep_ready                      | ON                                                  |+----------------------------------+-----------------------------------------------------+68 rows in set (0.04 sec)
     

主要参数说明

该集群原来是三个节点，一个节点从集群移出之后，wsrep_incoming_addresses 显示为了两个节点；

wsrep_cluster_status 在所在正常的节点中都显示为Primary ，显示为其他值时表示节点有异常

wsrep_flow_control_paused表示复制停止了多少秒

 

监控状态说明

集群完整性检查:

wsrep_cluster_state_uuid:在集群所有节点的值应该是相同的,有不同值的节点,说明其没有连接入集群.

wsrep_cluster_conf_id:正常情况下所有节点上该值是一样的.如果值不同,说明该节点被临时”分区”了.当节点之间网络连接恢复 的时候应该会恢复一样的值.

wsrep_cluster_size:如果这个值跟预期的节点数一致,则所有的集群节点已经连接.

wsrep_cluster_status:集群组成的状态.如果不为”Primary”,说明出现”分区”或是”split-brain”脑裂状况.

节点状态检查:

wsrep_ready: 该值为 ON,则说明可以接受 SQL 负载.如果为 Off,则需要检查 wsrep_connected.

wsrep_connected: 如果该值为 Off,且 wsrep_ready 的值也为 Off,则说明该节点没有连接到集群.(可能是 wsrep_cluster_address 或 wsrep_cluster_name 等配置错造成的.具体错误需要查看错误日志)

wsrep_local_state_comment:如果 wsrep_connected 为 On,但 wsrep_ready 为 OFF,则可以从该项查看原因.

复制健康检查:

wsrep_flow_control_paused:表示复制停止了多长时间.即表明集群因为 Slave 延迟而慢的程度.值为 0~1,越靠近 0 越好,值为 1 表示 复制完全停止.可优化 wsrep_slave_threads 的值来改善.

wsrep_cert_deps_distance:有多少事务可以并行应用处理.wsrep_slave_threads 设置的值不应该高出该值太多. 

wsrep_flow_control_sent:表示该节点已经停止复制了多少次.

wsrep_local_recv_queue_avg:表示 slave 事务队列的平均长度.slave 瓶颈的预兆.

最慢的节点的 wsrep_flow_control_sent 和 wsrep_local_recv_queue_avg 这两个值最高.这两个值较低的话,相对更好.

检测慢网络问题:

wsrep_local_send_queue_avg:网络瓶颈的预兆.如果这个值比较高的话,可能存在网络瓶

冲突或死锁的数目:

wsrep_last_committed:最后提交的事务数目

wsrep_local_cert_failures 和 wsrep_local_bf_aborts:回滚,检测到的冲突数目