The Ultimate Guide to High Availability with MariaDB
This is a read-only copy of the MariaDB Knowledgebase generated on 2024-11-15. For the latest, interactive version please visit https://mariadb.com/kb/.

MaxScale, "No Master can be determined"

Hi!

I am trying to use maxscale (2.2.15) with mariadb (10.2.15).

maxscale is running on ubuntu 16.04. (I tried to run maxscale also in a container, but similar problems occurred there also.) mariadb servers are in containers.

All are running on a single laptop.

I get an error when maxscale is started:

... oct 17 17:25:42 mycomputer maxscale[8973]: [MySQLAuth] Added user: INSERT OR REPLACE INTO mysqlauth_users VALUES ('maxscale', '127.0.0.1', 'mysql', 0, '...') oct 17 17:25:42 mycomputer maxscale[8973]: [MySQLAuth] Added user: INSERT OR REPLACE INTO mysqlauth_users VALUES ('maxscale', '<laptop_ip>', 'mysql', 0, '...') oct 17 17:25:42 mycomputer maxscale[8973]: [mariadbmon] No Master can be determined

I have tried to give different kinds of grants.

E.g.:

create user 'maxscale'@'127.0.0.1' identified by 'paswd';

grant SELECT on mysql.user to 'maxscale'@'127.0.0.1'; GRANT SELECT ON mysql.db TO 'maxscale'@'127.0.0.1'; GRANT SELECT ON mysql.tables_priv TO 'maxscale'@'127.0.0.1'; GRANT SELECT ON mysql.roles_mapping TO 'maxscale'@'127.0.0.1'; GRANT SHOW DATABASES ON *.* TO 'maxscale'@'127.0.0.1'; grant REPLICATION CLIENT on *.* to 'maxscale'@'127.0.0.1';

GRANT ALL PRIVILEGES ON *.* TO 'maxscale'@'127.0.0.%' IDENTIFIED BY 'paswd';

(Same with laptop IPs, ...)

Could only some correct grants be missing? Or something else?

I am testing only, so I could give some even more powerful / generic grants also. Just to get forward.

maxscale.cnf is below. Also output from maxadmin, list servers, is below.

BR Sam

Master Slave Slave

maxscale.cnf:

cat /etc/maxscale.cnf

[maxscale] threads=auto log_trace=1

[server1] type=server address=172.17.0.3 port=3306 protocol=MariaDBBackend

[server2] type=server address=172.17.0.4 port=3306 protocol=MariaDBBackend

[server3] type=server address=172.17.0.5 port=3306 protocol=MariaDBBackend

[WriteService] type=service router=readconnroute router_options=master servers=server1,server2,server3 user=maxscale passwd=paswd

[ReadService] type=service router=readconnroute router_options=slave servers=server1,server2,server3 user=maxscale passwd=paswd

[WriteListener] type=listener service=WriteService protocol=MariaDBClient port=4306 socket=/tmp/ClusterMaster

[ReadListener] type=listener service=ReadService protocol=MariaDBClient

  1. protocol=MySQLClient port=4307

[ReplicationMonitor] type=monitor

  1. module=galeramon module=mariadbmon servers=server1,server2,server3 user=maxscale passwd=paswd monitor_interval=1000

[CLI] type=service router=cli

[CLIListener] type=listener

maxadmin shows all of the servers, but all three only in "Running" state:

MaxScale> list servers Servers. -------------------+-----------------+-------+-------------+-------------------- Server | Address | Port | Connections | Status -------------------+-----------------+-------+-------------+-------------------- server1 | 172.17.0.3 | 3306 | 0 | Running server2 | 172.17.0.4 | 3306 | 0 | Running server3 | 172.17.0.5 | 3306 | 0 | Running -------------------+-----------------+-------+-------------+--------------------

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