G.3. General Questions

G.3.1. How do I update the IP address of one or more hosts in the cluster?
G.3.2. How do I update the password for the replication user in the cluster?
G.3.3. One of my hosts is regularly a number of seconds behind my other slaves?
G.3.4. How do you change the replicator heap size after installation?

G.3.1.

How do I update the IP address of one or more hosts in the cluster?

To update the IP address used by one or more hosts in your cluster, you must perform the following steps:

  1. If possible, switch the node into SHUNNED mode.

  2. Reconfigure the IP address on the machine.

  3. Update the hostname lookup, for example, by editing the IP configuration in /etc/hosts.

  4. Restart the networking to reconfigure the service.

  5. On the node that has changed IP address, run:

    shell> tpm update

    The above updates the configuration, but does not restart the individual services, which may still have the old, incorrect, IP address information for the host cached.

  6. Restart the node services:

    shell> tpm restart
  7. On each other node within the cluster:

    1. Update the hostname lookup for the new node, for example, by updating the IP configuration in /etc/hosts.

    2. Update the configuration, using tpm:

      shell> tpm update

    3. Restart the services:

      shell> tpm restart

G.3.2.

How do I update the password for the replication user in the cluster?

If you need to change the password used by Tungsten Clustering to connect to a dataserver and apply changes, the password can be updated first by changing the information within the your dataserver, and then by updating the configuration using tpm update. The new password is not checked until the Tungsten Replicator process is starting. Changing the password and then updating the configuration will keep replication from failing.

  1. Within cctrl set the maintenance policy mode:

    cctrl> set policy maintenance
  2. Within MySQL, update the password for the user, allowing the change to be replicated to the other datasources:

    mysql> SET PASSWORD FOR tungsten@'%' = PASSWORD('new_pass');
  3. Follow the directions for tpm update to apply the --datasource-password=new_pass setting.

  4. Set the policy mode in cctrl back to AUTOMATIC :

    cctrl> set policy automatic

G.3.3.

One of my hosts is regularly a number of seconds behind my other slaves?

The most likely culprit for this issue is that the time is different on the machine in question. If you have ntp or a similar network time tool installed on your machine, use it to update the current time across all the hosts within your deployment:

shell> ntpdate pool.ntp.org

Once the command has been executed across all the hosts, trying sending a heartbeat on the master to slaves and checking the latency:

shell> trepctl heartbeat

G.3.4.

How do you change the replicator heap size after installation?

You can change the configuration by running the following command from the staging directory:

shell> ./tools/tpm --host=host1 --java-mem-size=2048