[Java SDK] Implement async/non-blocking client for better performance

[chiradip]

Title: [Java SDK] Implement async/non-blocking client for better performance
Description:
The current Java SDK only provides blocking I/O operations through IggyTcpClient and IggyHttpClient. This severely limits performance in stream processing frameworks like Apache Flink.

Current State:

// Only blocking operations available
PolledMessages messages = client.messages().pollMessages(...); // Blocks thread

Proposed Solution:

// Add async operations
CompletableFuture<PolledMessages> future = client.messages().pollMessagesAsync(...);

Impact:

• Multi x performance improvement expected (To be measured)
• Essential for External (e.g Flink) connector efficiency
• Reduces thread usage from 10-15 to 2-4 per task

Implementation Suggestions:

• Use Netty for non-blocking I/O
• Provide CompletableFuture-based API
• Maintain backward compatibility with blocking client

[mmodzelewski]

Hi @chiradip,
Instead of adding a CompletableFuture API, it might be better to expose a reactive API with Project Reactor (Mono/Flux).

CompletableFuture covers single async results, but polling messages is naturally a streaming use case.

Reactor provides backpressure and integrates well with frameworks like Flink and WebFlux.

Example:

Mono<Stream> stream = client.streams().getStream(id);
Flux<PolledMessages> messages = client.messages().pollMessages(...);

[chiradip]

Thanks @mmodzelewski - you are right, we should consider using something like flux. also quarkus ecosystem has/had something similar. NOTE-TO-MYSELF - FILE AN ISSUE.

[chiradip]

PR merged. PR reference: #2213