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Using Wildcards

Hazelcast supports wildcard configuration for all distributed data structures that can be configured using Config, that is, for all except IAtomicLong, IAtomicReference. Using an asterisk (*) character in the name, different instances of maps, queues, topics, semaphores, etc. can be configured by a single configuration.

A single asterisk (*) can be placed anywhere inside the configuration name.

For instance, a map named com.hazelcast.test.mymap can be configured using one of the following configurations:

  • XML

  • YAML

<hazelcast>
    ...
    <map name="com.hazelcast.test.*">
        ...
    </map>

    <!-- OR -->

    <map name="com.hazel*">
        ...
    </map>

    <!-- OR -->

    <map name="*.test.mymap">
        ...
    </map>

    <!-- OR -->

    <map name="com.*test.mymap">
        ...
    </map>
    ...
</hazelcast>
hazelcast:
  map:
    com.hazelcast.test.*:
      ...
    com.hazel*:
     ...
    "*.test.mymap":
      ...
    com.*test.mymap:
      ...

Notice that when the "*" character prefixes a value, the whole value should be in quotes when you use the YAML configuration.

A queue named com.hazelcast.test.myqueue can be configured using one of the following configurations:

  • XML

  • YAML

<hazelcast>
    ...
    <queue name="*hazelcast.test.myqueue">
        ...
    </queue>

    <!-- OR -->

    <queue name="com.hazelcast.*.myqueue">
        ...
    </queue>
    ...
</hazelcast>
hazelcast:
  queue:
    "*hazelcast.test.myqueue":
    ...
    com.hazelcast.*.myqueue:
    ...
  • You can use only a single asterisk as a wildcard for each data structure configuration.

  • If you have matching wildcard configurations for a data structure, the most specific (longest) one is used when configuring it. Let’s say you have a map named mymap.customer.name and you have map configurations mymap.* and mymap.customer.*. Hazelcast uses mymap.customer.* to configure this map.

    As another example, assume that you have a map named mymap.customer.name, and map configurations mymap.*.name and mymap.customer.*. Hazelcast uses mymap.customer.* to configure this map. As you see, the longest character length before the asterisk makes it the most specific, so it wins the configuration.