Using Wildcards

Hazelcast members and Java clients support 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, near caches, 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>
xml
hazelcast:
  map:
    com.hazelcast.test.*:
      ...
    com.hazel*:
     ...
    "*.test.mymap":
      ...
    com.*test.mymap:
      ...
xml

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>
xml
hazelcast:
  queue:
    "*hazelcast.test.myqueue":
    ...
    com.hazelcast.*.myqueue:
    ...
xml
Note
  • 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.