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Each stream instance will use local counter to create stream thread name. So the above example will be always generating instance ids as:  A-1, A-2, B-1, B-2. By persisting instance ids generation, the static membership will still behave as expected when we configure > 1 stream instances in one JVM.

Also notice the original goal for using static integer to increment thread.id is to workaround the case where two stream instances configure same client.id in one JVM and trying to avoid conflict thread names. After this KIP, we are effectively removing this guard, so it is user's responsibility to configure unique client.ids if they don't want to see this single JVM conflict issue. We will do extra documentation on `client.id` config to remind user as necessary.

Public Interfaces

This change is internal, however it will affect KStream external information exposure. See next section.

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