/tc:tc-config/servers/mirror-group
A mirror group is a stripe in a TSA, consisting of one active server and one or more mirror (or backup) servers. A configuration that does not use the <mirror-group> element would produce a one-stripe TSA:
<servers>
<server name="A">
...
</server>
<server name="B">
...
</server>
<server name="C">
...
</server>
<server name="D">
...
</server>
...
</servers>
One of the named servers would assume the role of active (the one started first or that wins the election), while the remaining servers become mirrors. Note that in a typical stripe, having only one or two mirrors is sufficient and less taxing on the active server's resources (as it needs to sync with each mirror).
The following example shows the same servers split into two stripes:
<servers>
<mirror-group group-name="team1">
<server name="A">
...
</server>
<server name="B">
...
</server>
</mirror-group>
<mirror-group group-name="team2">
<server name="C">
...
</server>
<server name="D">
...
</server>
</mirror-group>
...
</servers>
Each stripe will have one active and one mirror server.
Note: Under <servers>, you may use either <server> or <mirror-group> configurations, but not both. All <server> configurations directly under <servers> work together as one mirror group, with one active server and the rest mirrors. To create more than one stripe, use <mirror-group> configurations directly under <servers>. The mirror group configurations then include one or more <server> configurations
For more examples and information, see
Configuring the Terracotta Server Array.