[Maria-discuss] New Question: Simple cluster two nodes, error.

11 Dec 2013

      Hello,

A new question has been asked in "MariaDB FAQ" by maximilianodipietro:
--------------------------------
Hi people, i have a two nodes cluster of MariaDb, and i need some help, i have this simple script to do a solve failover, the script works like this: if the master node dies, the script kills the slave and restart it as master, and then the master as slave when the script detects that the process is down, here's the code:

----------------------------------------------------------------------------------------------------------------------------------
#!/bin/bash

if [ $1 = "start" ]
then

PidMaria=$(ps -ef | grep wsrep_cluster  | grep -v grep | awk {'print $2'})
Server2=$(nmap -v ipnodo2 | grep 3306 | tail -n1 | awk {'print $2'})
TipoPid=$(ssh ipnodo2 "ps -ef |grep mysql | grep -v grep | cut -d "=" -f 2 | cut -d "/" -f 3 | cut -d "-" -f 1 | cut -d "." -f 1")
TipoPidLocal=$(ps -ef |grep mysql | grep -v grep | cut -d "=" -f 2 | cut -d "/" -f 3 | cut -d "-" -f 1 | cut -d "." -f 1)

if [ -z $PidMaria ]
then
#sleep 20
Server2=$(nmap -v ipnodo2 | grep 3306 | tail -n1 | awk {'print $2'})
        if [ -z $Server2 ]
        then
                        if [ -z $TipoPid ]
                        then
                                if [ -z $(ssh ipnodo2 "ps -ef |grep mysql | grep -v grep " | awk {'print $2'}) ]
                                then
                        /usr/sbin/mysqld --wsrep_cluster_address=gcomm:// --user=mysql --wsrep_sst_auth=root:root --wsrep_provider=/usr/lib64/galera/libgalera_smm.so
                                fi
                        else
                        /usr/sbin/mysqld --wsrep_cluster_address=gcomm://ipnodo2 --wsrep_sst_auth=root:root --user=mysql --wsrep_provider=/usr/lib64/galera/libgalera_smm.so
                        fi
        else
                        if [ -z $TipoPid ]
                        then
        /usr/sbin/mysqld --wsrep_cluster_address=gcomm://ipnodo2 --user=mysql --wsrep_sst_auth=root:root --wsrep_provider=/usr/lib64/galera/libgalera_smm.so
                       fi
       fi

else
        if [ -z $Server2 ]
        then
                if [ -z $TipoPidLocal ] 
                then
                echo "hola"
                else
                kill -9 $PidMaria
                /usr/sbin/mysqld --wsrep_cluster_address=gcomm:// --wsrep_sst_auth=root:root --user=mysql --wsrep_provider=/usr/lib64/galera/libgalera_smm.so
                fi
        else
                if [ -z $PidMaria ]
                then
                /usr/sbin/mysqld --wsrep_cluster_address=gcomm://ipnodo2 --user=mysql --wsrep_sst_auth=root:root --wsrep_provider=/usr/lib64/galera/libgalera_smm.so
        fi
        fi

fi
fi
--------------------------------------------------------------------------------------------------------------------------------

This is the error i get in the slave output when i run the script by hand.

---------------------------------------------------------------------------------------------------------------------------
+ /usr/sbin/mysqld --wsrep_cluster_address=gcomm://IPMASTER --user=mysql --wsrep_sst_auth=root:root --wsrep_provider=/usr/lib64/galera/libgalera_smm.so
131211 20:04:35 [Note] WSREP: Read nil XID from storage engines, skipping position init
131211 20:04:35 [Note] WSREP: wsrep_load(): loading provider library '/usr/lib64/galera/libgalera_smm.so'
131211 20:04:35 [Note] WSREP: wsrep_load(): Galera 23.2.7(r157) by Codership Oy <info@codership.com> loaded succesfully.
131211 20:04:35 [Note] WSREP: Found saved state: 1503cc31-6281-11e3-abfc-5bf96ca010d8:-1
131211 20:04:35 [Note] WSREP: Reusing existing '/var/lib/mysql//galera.cache'.
131211 20:04:35 [Note] WSREP: Passing config to GCS: base_host = IPLOCALHOST; base_port = 4567; cert.log_conflicts = no; gcache.dir = /var/lib/mysql/; gcache.keep_pages_size = 0; gcache.mem_size = 0; gcache.name = /var/lib/mysql//galera.cache; gcache.page_size = 128M; gcache.size = 128M; gcs.fc_debug = 0; gcs.fc_factor = 1; gcs.fc_limit = 16; gcs.fc_master_slave = NO; gcs.max_packet_size = 64500; gcs.max_throttle = 0.25; gcs.recv_q_hard_limit = 9223372036854775807; gcs.recv_q_soft_limit = 0.25; gcs.sync_donor = NO; replicator.causal_read_timeout = PT30S; replicator.commit_order = 3
131211 20:04:35 [Note] WSREP: Assign initial position for certification: -1, protocol version: -1
131211 20:04:35 [Note] WSREP: wsrep_sst_grab()
131211 20:04:35 [Note] WSREP: Start replication
131211 20:04:35 [Note] WSREP: Setting initial position to 00000000-0000-0000-0000-000000000000:-1
131211 20:04:35 [Note] WSREP: protonet asio version 0
131211 20:04:35 [Note] WSREP: backend: asio
131211 20:04:35 [Note] WSREP: GMCast version 0
131211 20:04:35 [Note] WSREP: (74e621f3-629f-11e3-a86f-0adb496b3ff6, 'tcp://0.0.0.0:4567') listening at tcp://0.0.0.0:4567
131211 20:04:35 [Note] WSREP: (74e621f3-629f-11e3-a86f-0adb496b3ff6, 'tcp://0.0.0.0:4567') multicast: , ttl: 1
131211 20:04:35 [Note] WSREP: EVS version 0
131211 20:04:35 [Note] WSREP: PC version 0
131211 20:04:35 [Note] WSREP: gcomm: connecting to group 'my_wsrep_cluster', peer '162.243.62.104:'
131211 20:04:35 [Note] WSREP: declaring 15031b4b-6281-11e3-9ad7-8a59b1f0cba0 stable
131211 20:04:35 [Note] WSREP: view(view_id(NON_PRIM,15031b4b-6281-11e3-9ad7-8a59b1f0cba0,8) memb {
        15031b4b-6281-11e3-9ad7-8a59b1f0cba0,
        74e621f3-629f-11e3-a86f-0adb496b3ff6,
} joined {
} left {
} partitioned {
        18299990-6281-11e3-a268-975810126780,
        a6d47aea-6281-11e3-b007-16991d53e685,
        d52af178-6281-11e3-871d-03c1e15f1ac4,
})
131211 20:05:05 [ERROR] WSREP: failed to open gcomm backend connection: 110: failed to reach primary view: 110 (Connection timed out)
         at gcomm/src/pc.cpp:connect():139
131211 20:05:05 [ERROR] WSREP: gcs/src/gcs_core.c:gcs_core_open():195: Failed to open backend connection: -110 (Connection timed out)
131211 20:05:05 [ERROR] WSREP: gcs/src/gcs.c:gcs_open():1289: Failed to open channel 'my_wsrep_cluster' at 'gcomm://IPMASTER': -110 (Connection timed out)
131211 20:05:05 [ERROR] WSREP: gcs connect failed: Connection timed out
131211 20:05:05 [ERROR] WSREP: wsrep::connect() failed: 6
131211 20:05:05 [ERROR] Aborting

131211 20:05:05 [Note] WSREP: Service disconnected.
131211 20:05:06 [Note] WSREP: Some threads may fail to exit.
131211 20:05:06 [Note] /usr/sbin/mysqld: Shutdown complete
------------------------------------------------------------------------------------------------

When the script starts the master from the crontab, the PID is already up, and i can access to the mariadb, but i cant write any database, only list the databases. 

[root@xxx ~]# mysql -uxxx -pxxxx
Welcome to the MariaDB monitor.  Commands end with ; or \g.
Your MariaDB connection id is 24
Server version: 5.5.33a-MariaDB

Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.

MariaDB [(none)]> create database TESTEOKILL2;
ERROR 1047 (08S01): Unknown command
MariaDB [(none)]> 

Any idea?. Thanks in advance!
--------------------------------

To view or answer this question please visit: http://mariadb.com/kb/en/simple-cluster-two-nodes-error/

[Maria-discuss] New Question: Simple cluster two nodes, error.

AskMonty KB