Does Hazelcast support thousands of clients?

Yes. However, there are some points you should consider.

• The environment should be a LAN with high stability and a network speed of 10 Gbps or higher.
• If the number of members is high, the client type should be selected as Dummy, not Smart Client.
• In the case of Smart Clients, since each client will open a connection to the members, these members should be powerful enough (for example, more cores) to handle hundreds or thousands of connections and client requests.
• Consider using Near Caches in clients to lower the network traffic.
• Use Hazelcast with the NIO implementation, which was introduced in Hazelcast 3.2.
• Configure the clients attentively. Please refer to the Java Client section of our documentation for configuration notes.