With the introduction of MySQL InnoDB Cluster we also got the
MySQL Shell (mysqlsh) interface. The shell offers scripting in
Javascript (default), SQL or Python. This offers a lot more
options for writing scripts on MySQL, for example it is much
easier now to use multiple server connections in a single
script.
A customer recently asked for a way to compare the transaction
sets between servers. That is useful when setting up replication
or identifying the server that has most transactions applied
already. So I wrote this little script which can be executed from
the OS shell:
#!/usr/bin/mysqlsh -f
// it is important to connect to the X protocol port,
// usually it is the traditional port + "0"
//
var serverA="root:root@localhost:40010"
var serverB="root:root@localhost:50010"
shell.connect(serverA)
var gtidA=session.sql("SELECT @@global.gtid_executed").execute().fetchOne()[0]
shell.connect(serverB) …
