I am debugging a checkout problem, where the shipping address is not saved. This can be reproduced only some times and on production, under unclear circumstances.
Checking the logs I found
Serialization failure: 1213 Deadlock found when trying to get lock; try restarting transaction, query was: UPDATE `quote_address` SET ...
And googling I found an post in the Magento community forums, stating that
cron_schedule might be involved with deadlocks.
I did a
mysql> select count(*) from cron_schedule; +----------+ | count(*) | +----------+ | 3778 | +----------+ 1 row in set (32.83 sec)
And it took very long. So I truncated the problem and seem to be not able to reproduce the problem any more at all (before in maybe 25% of the tries)
The Id column of the cron_schedule was around 14916548, so I am wondering if that is a problem for MySQL / MariaDB (5.5.5-10.0.38-MariaDB-0ubuntu0.16.04.1)?