how to mysqldump remote db from local machine

As I haven't seen it at serverfault yet, and the answer is quite simple:

Change:

ssh -f -L3310:remote.server:3306 user@remote.server -N

To:

ssh -f -L3310:localhost:3306 user@remote.server -N

And change:

mysqldump -P 3310 -h localhost -u mysql_user -p database_name table_name

To:

mysqldump -P 3310 -h 127.0.0.1 -u mysql_user -p database_name table_name

(do not use localhost, it's one of these 'special meaning' nonsense that probably connects by socket rather then by port)

edit: well, to elaborate: if host is set to localhost, a configured (or default) --socket option is assumed. See the manual for which option files are sought / used. Under Windows, this can be a named pipe.

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One can invoke mysqldump locally against a remote server.

Example that worked for me:

mysqldump -h hostname-of-the-server -u mysql_user -p database_name > file.sql

I followed the mysqldump documentation on connection options.

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mysqldump from remote server use SSL

1- Security with SSL

192.168.0.101 - remote server

192.168.0.102 - local server

Remore server

CREATE USER 'backup_remote_2'@'192.168.0.102' IDENTIFIED WITH caching_sha2_password BY '3333333' REQUIRE SSL;

GRANT ALL PRIVILEGES ON *.* TO 'backup_remote_2'@'192.168.0.102';

FLUSH PRIVILEGES;

-

Local server

sudo /usr/local/mysql/bin/mysqldump \
 --databases test_1 \
 --host=192.168.0.101 \
 --user=backup_remote_2 \
 --password=3333333 \
 --master-data \
 --set-gtid-purged \
 --events \
 --triggers \
 --routines \
 --verbose \
 --ssl-mode=REQUIRED \
 --result-file=/home/db_1.sql

====================================

2 - Security with SSL (REQUIRE X509)

192.168.0.101 - remote server

192.168.0.102 - local server

Remore server

CREATE USER 'backup_remote'@'192.168.0.102' IDENTIFIED WITH caching_sha2_password BY '1111111' REQUIRE X509;

GRANT ALL PRIVILEGES ON *.* TO 'backup_remote'@'192.168.0.102';

FLUSH PRIVILEGES;

-

Local server

sudo /usr/local/mysql/bin/mysqldump \
 --databases test_1 \
 --host=192.168.0.101 \
 --user=backup_remote \
 --password=1111111 \
 --events \
 --triggers \
 --routines \
 --verbose \
 --ssl-mode=VERIFY_CA \
 --ssl-ca=/usr/local/mysql/data/ssl/ca.pem \
 --ssl-cert=/usr/local/mysql/data/ssl/client-cert.pem \
 --ssl-key=/usr/local/mysql/data/ssl/client-key.pem \
 --result-file=/home/db_name.sql

[Note]

On local server

/usr/local/mysql/data/ssl/

-rw------- 1 mysql mysql 1.7K Apr 16 22:28 ca-key.pem
-rw-r--r-- 1 mysql mysql 1.1K Apr 16 22:28 ca.pem
-rw-r--r-- 1 mysql mysql 1.1K Apr 16 22:28 client-cert.pem
-rw------- 1 mysql mysql 1.7K Apr 16 22:28 client-key.pem

Copy this files from remote server for (REQUIRE X509) or if SSL without (REQUIRE X509) do not copy

On remote server

/usr/local/mysql/data/

-rw------- 1 mysql mysql 1.7K Apr 16 22:28  ca-key.pem
-rw-r--r-- 1 mysql mysql 1.1K Apr 16 22:28  ca.pem
-rw-r--r-- 1 mysql mysql 1.1K Apr 16 22:28  client-cert.pem
-rw------- 1 mysql mysql 1.7K Apr 16 22:28  client-key.pem
-rw------- 1 mysql mysql 1.7K Apr 16 22:28  private_key.pem
-rw-r--r-- 1 mysql mysql  451 Apr 16 22:28  public_key.pem
-rw-r--r-- 1 mysql mysql 1.1K Apr 16 22:28  server-cert.pem
-rw------- 1 mysql mysql 1.7K Apr 16 22:28  server-key.pem

my.cnf

[mysqld]
# SSL
ssl_ca=/usr/local/mysql/data/ca.pem
ssl_cert=/usr/local/mysql/data/server-cert.pem
ssl_key=/usr/local/mysql/data/server-key.pem

Increase Password Security

https://dev.mysql.com/doc/refman/8.0/en/password-security-user.html

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Bassed on this page here:

Compare two MySQL databases

I modified it so you can use ddbb in diferent hosts.

#!/bin/sh

echo "Usage: dbdiff [user1:pass1@dbname1:host] [user2:pass2@dbname2:host] [ignore_table1:ignore_table2...]"

dump () {
  up=${1%%@*}; down=${1##*@}; user=${up%%:*}; pass=${up##*:}; dbname=${down%%:*}; host=${down##*:};
  mysqldump --opt --compact --skip-extended-insert -u $user -p$pass $dbname -h $host $table > $2
}

rm -f /tmp/db.diff

# Compare
up=${1%%@*}; down=${1##*@}; user=${up%%:*}; pass=${up##*:}; dbname=${down%%:*}; host=${down##*:};
for table in `mysql -u $user -p$pass $dbname -h $host -N -e "show tables" --batch`; do
  if [ "`echo $3 | grep $table`" = "" ]; then
    echo "Comparing '$table'..."
    dump $1 /tmp/file1.sql
    dump $2 /tmp/file2.sql
    diff -up /tmp/file1.sql /tmp/file2.sql >> /tmp/db.diff
  else
    echo "Ignored '$table'..."
  fi
done
less /tmp/db.diff
rm -f /tmp/file1.sql /tmp/file2.sql

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