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In order to eliminate these drawbacks is proposed implementation using ZooKeeper-a service. As a point of connection and synchronization for all server nodes of Apache Ignite cluster is a ZooKeeper .

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Thus ZooKeeper cluster is to guarantee the storage of the current topology, attribute nodes, the next connection nodes, queues for storing user and service events.

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ZooKeeper main functionality is to provide for the allocation process through shared a shared hierarchy, service coordination and , and synchronization.

At the same time, it provided a guarantee that:

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1. The configuration of each server node Apache Ignite specified range of addresses and ports for connection to ZooKeeper cluster.

2. Each server Apache Ignite node is connected to an arbitrary server ZooKeeper.

1. Creates a new entry in the / joinData data connection.

2. Recorded in the ephemeral znode / alive - the list of all active nodes in the topology.

3. It checks whether it is a focal point.

4. Subscribes to notifications on changes in / discoveryEvents

5. subscribes to receive notification of a registered output of the previous node from /alive

3. coordinator, having received notification that a / alive, a new node

1. processes data from / joinData, checking that the node may be included in the topology.

2. Creates event nodeJoin and writes it to / discoveryEvents

4. nodes topology, received notice that / discoveryEvents, a new message is processed topology change.

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Disabling a node from the cluster Apache Ignite

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It should be noted that the mechanism customEvent implemented informing nodes of the early formation of a snapshot. This implies a modification of the message sent by topology. In the current implementation of the communication are immutable, which will require improvements in the mechanism of formation of snapshots.

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Risks and Assumptions

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