mysqldump Wordpress issue

[BigBang]

While doing mysqldump command for databases about 2GB I get an error in Wordpress sites "error establishing database connection". It's about 10-15 sec while mysqldump is running.

Can someone help me where should I digging?

max_user_connections = 50
max_connections = 800

Server 48 cores, 128 GB RAM

Thanks in advance.