说MGR - MGR的监控

表performance_schema.replication_group_member_stats可以显示MGR成员的诸多统计信息。

[root@mysql.sock][performance_schema]> select * from replication_group_member_stats\G

*************************** 1. row ***************************

CHANNEL_NAME: group_replication_applier

VIEW_ID: 15683632267713610:5

MEMBER_ID: 77731d39-bc4c-11e9-956d-080027aa34ac

COUNT_TRANSACTIONS_IN_QUEUE: 7

COUNT_TRANSACTIONS_CHECKED: 209004

COUNT_CONFLICTS_DETECTED: 0

COUNT_TRANSACTIONS_ROWS_VALIDATING: 174106

TRANSACTIONS_COMMITTED_ALL_MEMBERS: 27a60549-a643-11e9-bc30-080027f22add:1-4,

aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:1-2465742

LAST_CONFLICT_FREE_TRANSACTION: aaaaaaaa-aaaa-aaaa-aaaa-aaaaaaaaaaaa:2552795

1 row in set (0.00 sec)

重点字段的含义如下：

COUNT_TRANSACTIONS_IN_QUEUE - The number of transactions in the queue pending conflict detection checks. Once the transactions have been checked for conflicts, if they pass the check, they are queued to be applied as well.

COUNT_TRANSACTIONS_CHECKED - The number of transactions that have been checked for conflicts.

COUNT_CONFLICTS_DETECTED - The number of transactions that have not passed the conflict detection check.

COUNT_TRANSACTIONS_ROWS_VALIDATING - Number of transactions which can be used for certification, but have not been garbage collected. Can be thought of as the current size of the conflict detection database against which each transaction is certified.

TRANSACTIONS_COMMITTED_ALL_MEMBERS - The transactions that have been successfully committed on all members of the replication group, shown as GTID Sets. This is updated at a fixed time interval.

LAST_CONFLICT_FREE_TRANSACTION - The transaction identifier of the last conflict free transaction which was checked.