Mysql replication-Master-Master

MySQL Master-Master replication.

Master-1 my.cnf configuration:

mkdir /var/lib/mysql/log/
log-bin=/var/lib/mysql/log/mysql-bin
log_warnings
log_slow_queries = /var/lib/mysql/log/slow.log
long_query_time = 5
log_long_format
tmpdir = /tmp
server-id = 1
log_slave_updates
replicate-same-server-id = 0
auto_increment_increment = 10
auto_increment_offset = 1
relay-log = mysql-relay-bin

Master-2 my.cnf configuration:
mkdir /var/lib/mysql/log/
log-bin=/var/lib/mysql/log/mysql-bin
log_warnings
log_slow_queries = /var/lib/mysql/log/slow.log
long_query_time = 5
log_long_format
tmpdir = /tmp
server-id = 2
replicate-same-server-id = 0
auto_increment_increment = 2
auto_increment_offset = 2
relay-log = mysql-relay-bin

First setup Master1 as Master and Master2 as slave for Master-1:

Follow below steps:
On Master-1:

grant replication slave on *.* to 'root'@'192.168.216.135' identified by 'admin';
show master status;

It shows file name and position, Use these records on Master-2 to run it as slave for Master-1.
Step 3: Now log on to master-2 and run the below query:

CHANGE MASTER TO MASTER_HOST='192.168.216.130', MASTER_USER='root',MASTER_PASSWORD='admin', MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=106;

Step 4: start slave
Step 5: show slave status \G

On this status, the following 2 records should be as follows
Slave_IO_Running: Yes
Slave_SQL_Running: Yes

These 2 records indicates Replication status. If these parameters show “Yes” that means replication is running successfully.

Setup Master2 as Master and Master1 as slave for Master-2:

On Master-2 server:

grant replication slave on *.* to 'root'@'192.168.216.130' identified by 'admin

Step 2: mysql> show master status;

Step 3: Now log on to master-1 and run the below query:
CHANGE MASTER TO MASTER_HOST='192.168.216.135', MASTER_USER='root',MASTER_PASSWORD='admin', MASTER_LOG_FILE='mysql-bin.000001',MASTER_LOG_POS=346;
Step 4: start slave
Step 5: show slave status \G

The following parameters should show “Yes”, so that replication is running successfully

Slave_IO_Running: Yes
Slave_SQL_Running: Yes

On both servers “slave_IO_Running” and “slave_SQL_Running” parameters should always be “Yes” for successful Master-Master Replication.

Openstack Live Migration failure: operation failed

Error in the error log nova/compute

2014-06-25 01:32:50.752 2703 ERROR nova.virt.libvirt.driver [-]
[instance: fc118bff-77a3-4300-ab27-371a314b819f] Live Migration failure: operation failed: Failed to connect to remote libvirt URI qemu+tcp://compute2/system

Try updating the libvirt configurations. Modify /etc/libvirt/libvirtd.conf. To see all of the available options

1. 
   

   before : #listen_tls = 0
   after : listen_tls = 0
   
   before : #listen_tcp = 1
   after : listen_tcp = 1
   
   add: auth_tcp = "none"

   
   

Openstack+ Shared Storage(NFS) +Permission denied

While setting up Openstack with shared storage , If we get following error while creating a instance ensure that the server is in permissive selinux mode with

getenfonce

and if that too doesn't work try giving 755 permission to the mounted directory here its /var/lib/nova

2014-06-24 18:58:20.642 5119 TRACE nova.compute.manager [instance: a7996f1f-9af2-4410-8351-139d43f00786] libvirtError: internal error Process exited while reading console log output: qemu-kvm: -chardev file,id=charserial0,path=/var/lib/nova/instances/a7996f1f-9af2-4410-8351-139d43f00786/console.log: Could not open '/var/lib/nova/instances/a7996f1f-9af2-4410-8351-139d43f00786/console.log': Permission denied

 

At last if nothing else worked , tell libvirtd/qemu to use root user to access datas.
[root@compute nova]# cat /etc/libvirt/qemu.conf |grep root
user = "root"
#group = "root"
[root@compute nova]#