IdGenerator

class IdGenerator(client, service_name, name, atomic_long)

Bases: hazelcast.proxy.base.Proxy

The IdGenerator is responsible for creating unique ids (a long) in a cluster. In theory, an AtomicLong.increment_and_get() could be used to provide the same functionality. The big difference is that the increment_and_get() requires one or more remote calls for every invocation which cause a performance and scalability bottleneck. The IdGenerator uses an AtomicLong under the hood, but instead of doing remote call for every call to new_id(), it does it less frequently. It checks out a chunk, e.g. 1..1000 and as long as it has not yet consumed all the ids in its chunk, then no remote call is done. IDs generated by different cluster members may get out of order because each member will get its own chunk. It can be that member 1 has chunk 1..1000 and member 2 has 1001..2000. Therefore, member 2 will automatically have ids that are out of order with the ids generated by member 1.

init(initial)

Try to initialize this IdGenerator instance with the given id. The first generated id will be 1 greater than id.

Parameters

initial – (long), the given id.

Returns

(bool), true if initialization succeeded, false if id is less than 0.

new_id()

Generates and returns a cluster-wide unique id. Generated ids are guaranteed to be unique for the entire cluster as long as the cluster is live. If the cluster restarts, then id generation will start from 0.

Returns

(long), cluster-wide new unique id.