MySQL Galera cluster叢集常用引數說明

1、wsrep_local_state_uuid：
與叢集的wsrep_cluster_state_uuid一致
)]> show status like '%wsrep_%_state_uuid%';
+--------------------------+--------------------------------------+
| Variable_name            | Value                                |
+--------------------------+--------------------------------------+
| wsrep_local_state_uuid   | eebe303f-5262-11e8-9e80-8a8d79151541 |
| wsrep_cluster_state_uuid | eebe303f-5262-11e8-9e80-8a8d79151541 |
+--------------------------+--------------------------------------+

2、wsrep_last_committed：
叢集已經提交事務數目，是一個累計值，所有節點應該相等，如果出現不一致，說明事務有延遲，可以用來計算延遲。
)]> show status like '%wsrep_last_committed%';
+----------------------+--------+
| Variable_name        | Value  |
+----------------------+--------+
| wsrep_last_committed | 115562 |
+----------------------+--------+

3、wsrep_replicated：
從本地節點複製出去的寫集(write set)數目，wsrep_replicated_bytes為寫集的總位元組數；可以用於參考節點之間的負載均衡是否平衡；該值較大的節點較為繁忙。
)]> show status like '%wsrep_replicated%';
+------------------------+----------+
| Variable_name          | Value    |
+------------------------+----------+
| wsrep_replicated       | 13579    |
| wsrep_replicated_bytes | 35585864 |
+------------------------+----------+

4、wsrep_received：
與wsrep_replicated對應，表示接收來自其他節點的寫集(write set)數目.
)]> show status like '%wsrep_received%';
+----------------------+----------+
| Variable_name        | Value    |
+----------------------+----------+
| wsrep_received       | 11036    |
| wsrep_received_bytes | 35576367 |
+----------------------+----------+

5、wsrep_local_commits：
從本地節點發出的寫集(write set)被提交的數目，不超過wsrep_replicated的數目。
)]> show status like '%wsrep_local_commits%';
+---------------------+-------+
| Variable_name       | Value |
+---------------------+-------+
| wsrep_local_commits | 13582 |
+---------------------+-------+

6、wsrep_local_cert_failures：
同步過程中節點認證失敗計數，衝突來自本地提交的事務和同步佇列中事務存在鎖衝突，則本地驗證失敗（保證全域性資料一致性）。
)]> show status like '%wsrep_local_cert_failures%';
+---------------------------+-------+
| Variable_name             | Value |
+---------------------------+-------+
| wsrep_local_cert_failures | 0     |
+---------------------------+-------+

7、wsrep_local_bf_aborts：
強制放棄的寫集數目，本地事務和同步佇列中正在執行的事務存在鎖衝突時，將強制保證先提交的事務成功，後者回滾或報錯。
)]> show status like '%wsrep_local_bf_aborts%';
+-----------------------+-------+
| Variable_name         | Value |
+-----------------------+-------+
| wsrep_local_bf_aborts | 1     |
+-----------------------+-------+

8、wsrep_local_send_queue：
傳送佇列的長度。wsrep_local_send_queue_avg：從上次查詢狀態到目前傳送佇列的平均長度，>0.0意味著複製過程被節流了。
)]> show status like '%wsrep_local_send_queue%';
+----------------------------+----------+
| Variable_name              | Value    |
+----------------------------+----------+
| wsrep_local_send_queue     | 0        |
| wsrep_local_send_queue_max | 2        |
| wsrep_local_send_queue_min | 0        |
| wsrep_local_send_queue_avg | 0.000145 |
+----------------------------+----------+

9、wsrep_local_recv_queue：
接收佇列的長度，與wsrep_local_send_queue對應。
)]> show status like '%wsrep_local_send_queue%';
+----------------------------+----------+
| Variable_name              | Value    |
+----------------------------+----------+
| wsrep_local_send_queue     | 0        |
| wsrep_local_send_queue_max | 2        |
| wsrep_local_send_queue_min | 0        |
| wsrep_local_send_queue_avg | 0.000145 |
+----------------------------+----------+

10、wsrep_cert_deps_distance：
可以並行執行的寫集(write set)的最大seqno與最小seqno之間的平均差值。
)]> show status like '%wsrep_cert_deps_distance%';
+--------------------------+-----------+
| Variable_name            | Value     |
+--------------------------+-----------+
| wsrep_cert_deps_distance | 33.977434 |
+--------------------------+-----------+

11、wsrep_apply_oooe：
佇列中事務併發執行佔比，值越高意味著效率越高。
)]> show status like '%wsrep_apply_oooe%';
+------------------+----------+
| Variable_name    | Value    |
+------------------+----------+
| wsrep_apply_oooe | 0.006204 |
+------------------+----------+

12、wsrep_commit_window：
平均併發提交視窗大小。
)]> show status like '%wsrep_commit_window%';
+---------------------+----------+
| Variable_name       | Value    |
+---------------------+----------+
| wsrep_commit_window | 1.000423 |
+---------------------+----------+

13、wsrep_local_state：
節點的狀態,取值1-6。
取值1：The node starts and establishes a connection to the Primary Component.
取值2：When the node succeeds with a state transfer request, it begins to cache write-sets.
取值3：The node receives a State Snapshot Transfer. It now has all cluster data and begins to apply the cached write-sets.
Here the node enables Flow Control to ensure an eventual decrease in the slave queue.
取值4：The node finishes catching up with the cluster. Its slave queue is now empty and it enables Flow Control to keep it empty.
The node sets the MySQL status variable wsrep_ready to the value 1. The node is now allowed to process transactions.
取值5：The node receives a state transfer request. Flow Control relaxes to DONOR. The node caches all write-sets it cannot apply.
取值6：The node completes the state transfer to joiner node.
)]> show status like '%wsrep_local_state%';
+---------------------------+--------------------------------------+
| Variable_name             | Value                                |
+---------------------------+--------------------------------------+
| wsrep_local_state_uuid    | eebe303f-5262-11e8-9e80-8a8d79151541 |
| wsrep_local_state         | 4                                    |
| wsrep_local_state_comment | Synced                               |
+---------------------------+--------------------------------------+

14、wsrep_incoming_addresses：
叢集中其它節點的地址，多個地址之間用逗號分隔。
)]> show status like '%wsrep_incoming_addresses%';
+--------------------------+-------------------------- -+
| Variable_name            | Value                      |
+--------------------------+-------------------------- -+
| wsrep_incoming_addresses | IP1:3306,IP2:3306,IP3:3306 |
+--------------------------+----------------------------+

15、wsrep_cluster_conf_id：
叢集節點關係改變的次數（每次增加/刪除都會+1）。
)]> show status like '%wsrep_cluster_conf_id%';
+-----------------------+-------+                        
| Variable_name         | Value |                        
+-----------------------+-------+                        
| wsrep_cluster_conf_id | 53    |                        
+-----------------------+-------+      

16、wsrep_cluster_size：叢集節點個數。
)]> show status like '%wsrep_cluster_size%';
+--------------------+-------+
| Variable_name      | Value |
+--------------------+-------+
| wsrep_cluster_size | 3     |
+--------------------+-------+
17、wsrep_cluster_status：
叢集的目前狀態，取值：PRIMARY（正常）/NON_PRIMARY（不一致）。
)]> show status like '%wsrep_cluster_status';
+----------------------+---------+
| Variable_name        | Value   |
+----------------------+---------+
| wsrep_cluster_status | Primary |
+----------------------+---------+
18、wsrep_connected：
節點是否連線到叢集，取值：ON/OFF。
)]> show status like 'wsrep_connected';
+-----------------+-------+
| Variable_name   | Value |
+-----------------+-------+
| wsrep_connected | ON    |
+-----------------+-------+

19、wsrep_local_index：
節點id，取值從0開始。This node index in the cluster (base 0).
)]> show status like 'wsrep_local_index';
+-------------------+-------+
| Variable_name     | Value |
+-------------------+-------+
| wsrep_local_index | 0     |
+-------------------+-------+

20、wsrep_ready：
節點是否接收查詢，即節點是否可正常使用。
)]> show status like '%wsrep_ready%';
+---------------+-------+
| Variable_name | Value |
+---------------+-------+
| wsrep_ready   | ON    |
+---------------+-------+

完整詳細的引數說明可參考官方文件：http://galeracluster.com/documentation-webpages/galerastatusvariables.html?highlight=wsrep_local_index#wsrep-local-index

----------------------------------------------------End By TangYun20180516-----------------------------------------------------