I am using Apache Ignite with a Java application and observing that with increasing concurrency, response times also increases. I noticed that there is only one connection established between the java application and the Ignite server. How can I confirm if that is the bottleneck? Thread dumps reveal that some threads are waiting for the Socket.Read method. Is it relatable to number of connections?
As of Ignite 2.7.6, Thin Client establishes only one connection to the server node. Yes, it can become a bottleneck when used from multiple threads.
I can recommend either having one IgniteClient instance per thread, or using some kind of a connection pool.
Also, Ignite 2.8 introduces Partition Awareness (release is planned for today), where thin client connection is established to every specified server node, and key-based requests are dispatched to primary nodes. This may help in your case as well.