If you want to limit outbound message queue size, you just need to create instance of TcpCommunicationSpi, and pass it to IgniteConfiguration:
public IgniteConfiguration clientIgniteConfiguration() {
IgniteConfiguration igniteConfiguration = new IgniteConfiguration();
TcpCommunicationSpi tcpCommunicationSpi = new TcpCommunicationSpi();
tcpCommunicationSpi.setMessageQueueLimit(1024);
igniteConfiguration.setCommunicationSpi(tcpCommunicationSpi);
...
return igniteConfiguration;
}If you still have any questions, feel free to ask me in the comments under this article, or write me on promark33@gmail.com.