For the cluster address (where to connect to cluster at) Galera takes URL in the form
<backend schema>://<cluster address>[?option1=value1[&option2=value2]]
which can be optionally followed by a list of
key=value queries according to URL standard. In 0.7 it is the only way to customized Galera parameters. In 0.8 values supplied in the URL take precedence over the values supplied in
NOTE: Values supplied in the URL are valid only for this connection instance and need to be resupplied on every new connection to cluster. In 0.8 customized parameters can be made durable by putting them in
Galera currently supports 2 schemata:
wsrep_provider_optionsstarting with 0.8.x)
Cluster address should be either
It can be either IP address or a DNS name optionally followed by port number.
As of version 2.2 Galera supports a comma-separated list of cluster members in the cluster address like:
Only use empty
gcomm:// address when you want create a NEW cluster. Never use it when your intention is to reconnect to an existing one. Therefore never leave it hardcoded in any configuration files.
One way to avoid editing my.cnf in order to remove
gcomm:// is to start all cluster nodes with the following URL:
'pc.wait_prim=no' option which makes the node to wait for primary component indefinitely.) Then bootstrap the primary component by setting
'pc.bootstrap=1' on any one of the nodes.
Option list can be used to set backend parameters, like listen address, timeout values and such. In 0.7.x it was the only way to customize Galera behavior. Parameter values set in the option list are not durable and need to be resubmitted on every connection to cluster. Parameters specified in the URL take precedence over parameters specified elsewhere (e.g. wsrep_provider_options in my.cnf).
Parameters that can be set through the option list are “evs.*”, “pc.*”, “gmcast.*”.
If not set in parameter list gcomm will listen on all interfaces.
If not set in parameter list listen port will be taken from the cluster address. If not specified in the cluster address the port will be set to default: 4567.