Shulou(Shulou.com)05/31 Report--

This article introduces what is the most common note log in Mysql5.7 's error log, which is very detailed. Interested friends can use it for reference. I hope it will be helpful to you.

The following are the three most common note logs

The first kind, Aborted connection. :

[Note] Aborted connection 61 to db: 'unconnected' user:' mha' host: '197.xx.xx.xx (Got an error reading communication packets)

The reason is due to the network and other reasons.

[Note] Aborted connection 61 to db: 'unconnected' user:' mha' host: '197.xx.xx.xx (Got timeout reading communication packets)

The reason is that the idle time of the session has reached the timeout time specified by the database.

The second kind: information of SLAVE multithread synchronization

2016-03-14T15:48:26.432150Z 73 [Note] Multi-threaded slave statistics for channel ": seconds elapsed = 121; eventsassigned = 100374529; worker queues filled over

Overrun level = 0; waited due aWorker queue full = 0; waited due the total size = 0; waited at clock conflicts= 1451875661700 waited (count) whenWorkers occupied = 3211993 waited whenWorkers occupied = 445032386000

Events assigned: the total number of event allocated for execution is the total.

Worker queues filled over overrun level: in multithreaded synchronization, the number of times the private queue length of worker is too long, which is counted as the total.

Waited due a Worker queue full: the number of waits due to the long queue of worker, which is the total.

Waited due the total size: the number of times the maximum size has been exceeded, which is specified by the parameter slave_pending_jobs_size_max.

Waited at clock conflicts: wait time in nanoseconds due to logical time conflicts.

Waited (count) when Workers occupied: the number of times a wait occurred because the workder was occupied. (total value).

Waited when Workersoccupied: the total time to wait because the workder is occupied, in nanoseconds.

The third type: output log of page_cleaner thread

[Note] InnoDB:page_cleaner: 1000ms intended loop took 4750ms.The

Settings might not be optimal. Flushed=1519 and evicted=0, during the time.

This refresh time-the last refresh time > 1 second (sleep time) + 3 seconds is a warning. It is generally due to insufficient IO capability.

Parameter optimization (designed to reduce the amount of each refresh and make the number of blocks per refresh more average):

Innodb_io_capacity should be reduced.

Innodb_max_dirty_pages_pct should be reduced.

If innodb_max_dirty_pages_pct_lwm is set, you should consider reducing it.

Innodb_io_capacity_max decrease

About the Mysql5.7 error log how the most common note log is shared here, I hope the above content can be of some help to you, can learn more knowledge. If you think the article is good, you can share it for more people to see.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.