High DB Load

High DB load usually is the cause of the 302 Global Call Limit reached problem for M2.

It looks like this:

As an example we see that load started to grow at ~09:46

We can check log files at the similar time.

Here in /var/log/m2/gui_crash.log we can find:

--------------------------------------------------------------------------------
ID:         20181008094632
Class:      Mysql2::Error
Message:    Lock wait timeout exceeded; try restarting transaction
Controller: tariffs
Action:     import_csv2
----------------------------------------

Which clearly shows us that problem was caused by importing CSV Tariff file.

Line ID:20181008094632 tells us the exact time when error occured: 2018-10-08 09:46:32

We can find such file in /tmp folder by the Modify Time and with name import_csv......csv

Then we can check /var/log/mysql.log

As an example we could see such error:

InnoDB: ERROR: the age of the last checkpoint is 9434252,
InnoDB: which exceeds the log group capacity 9433498.
InnoDB: If you are using big BLOB or TEXT rows, you must set the
InnoDB: combined size of log files at least 10 times bigger than the
InnoDB: largest such row.

Solution: InnoDB: ERROR: the age of the last checkpoint