MySQLdump leads to exceeding max connections. Skip-Quick as a solution? Every night I do a full mysqldump of a 17G DB in MySQL 5.7.32. This worke for years, now I am doing some heavy load on inserts during the night which caused at exactly the backup time the connections to rise to max_connections which led to connections errors.
As the Server has enough RAM 64G (30G free), I increased max_connections from 150 to 300 in a first reaction.
However looking at the dump command I found the option -- quick (also enabled by default) which tells me that it is exporting row by row.
--single-transaction --routines --quick --compact

I am thinking of changing this to --skip-quick. but dare to change this since I would need to check the restore again and this is very time consuming.
Looking at the connections over time I also noticed that there are some interruptions around that time period. So maybe connections stack up since there is a block during MySQLdump?
MySQL error log shows a large amount of the following error, although not at this time points but continuously throughout the day:
Aborted connection 63182018 to db: 'mydb' user: 'test' host: 'myhost' (Got an error reading communication packets)

How would you approach this problem?
mysqldump takes only 1 connection.
There is 1 extra connection for root.  (Note the 151 vs 152.)  I hope you are not using root for your app; change that if you are.  Then allow mysqldump to be the only root process running when it is doing a dump.
Limite the number of connections requested -- by adjusting the web server (or whatever is doing connections).  Web servers tend to allow far more children than is efficient.
Disconnect (in the app) from MySQL when finished processing.
Lower wait_timeout -- this will lead to disconnecting idle threads or threads that are held unnecessarily long by a &quot;connection pool&quot;.
Running mysqldump takes resources away from other queries; be sure to run it at off times.
Use the slowlog to find out what queries are the most impacted by the dump; then let's discuss improving them.
If you have an LVM snapshot, why bother with mysqldump?  LVM is so much faster and less invasive.