8. ClustrixDB 监控

一、 列出集群中当前会话

sql> select * from system.sessions\G

二、 显示CPU利用率、磁盘读/写利用率和缓冲区缓存失误率

MySQL [system]> show load;
+--------------+------+
| facility | LOAD |
+--------------+------+
| bm_miss_rate | 0 |
| cpu | 0.1 |
| disk_util | NULL |
+--------------+------+

三、监控集群中表大小

SELECT dbs.name AS `Database`,
               rs.name AS `Table`,
               rs.bytes/1024/1024 AS `Mb`
FROM   system.`relation_sizes` AS rs,
             system.`databases` AS dbs
WHERE rs.database = dbs.db order by mb desc;

四、使用statd监视集群

http://docs.clustrix.com/display/CLXDOC/Monitoring+Your+Cluster+Using+statd

列出消耗CPU最大的3个历史SQL

SELECT nodeid, exec_count, exec_ms, exec_ms/exec_count as avg_ms, left(statement,100)
     FROM system.qpc_queries
     ORDER BY exec_ms desc
     LIMIT 3;

列出过去24小时内最频繁运行的100个SQL

sql> SELECT query_key,

             min(rank),
             max(rank),
             database,
             left(statement,100),
             sum(exec_count) as calc_exec_count,
             round(avg(avg_rows_read)) as calc_avg_rows_read,
             round(avg(avg_exec_ms)) as calc_avg_exec_ms
     FROM    clustrix_statd.qpc_history
     WHERE   timestamp BETWEEN (now() - interval 24 hour) AND now()
     AND     database !='clustrix_statd'
     GROUP BY query_key
     ORDER BY calc_exec_count     DESC,
              calc_avg_rows_read  DESC
     LIMIT 100;

列出过去24小时内返回行数最多的100个SQL

sql> SELECT query_key,
            min(rank),
            max(rank),
            database,
            left(statement,100),
            sum(exec_count) as calc_exec_count,
            round(avg(avg_rows_read)) as calc_avg_rows_read,
            round(avg(avg_exec_ms)) as calc_avg_exec_ms
     FROM   clustrix_statd.qpc_history
     WHERE  timestamp BETWEEN (now() - interval 24 hour) AND now()
     AND    database !='clustrix_statd'
     GROUP BY query_key
     ORDER BY calc_avg_rows_read DESC,
              calc_exec_count DESC
     LIMIT 100;

列出过去24小时内返回运行时间最长的100个SQL

sql> SELECT query_key,
            min(rank),
            max(rank),
            database,
            left(statement,100),
            sum(exec_count) as calc_exec_count,
            round(avg(avg_rows_read)) as calc_avg_rows_read,
            round(avg(avg_exec_ms)) as calc_avg_exec_ms
     FROM   clustrix_statd.qpc_history
     WHERE  timestamp BETWEEN (now() - interval 24 hour) AND now()
     AND    database !='clustrix_statd'
     GROUP BY query_key
     ORDER BY calc_avg_exec_ms  DESC,
              calc_exec_count   DESC
     LIMIT 100;

五、监控Rebalance

sql> select * from system.rebalancer_activity_log order by started desc limit 10; 

六、检查数据库参数不是默认值的参数

SELECT name, value, default_value
     FROM system.global_variables
     JOIN system.global_variable_definitions USING (name)
     WHERE value != default_value
     AND name NOT IN
          ('cluster_id', 'cluster_name', 'clustrix_version', 'customer_name', 'format_version',
           'global_variables_ignored_version', 'license', 'mysql_port', 'server_id',
           'ssl_cert', 'ssl_key', 'view_strmaps_upgraded');

七、