diff --git a/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/CoapTransportResource.java b/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/CoapTransportResource.java index 3e291a8177..86ac404aa2 100644 --- a/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/CoapTransportResource.java +++ b/common/transport/coap/src/main/java/org/thingsboard/server/transport/coap/CoapTransportResource.java @@ -169,7 +169,7 @@ public class CoapTransportResource extends AbstractCoapTransportResource { } private void processProvision(CoapExchange exchange) { - exchange.accept(); + deferAccept(exchange); try { UUID sessionId = UUID.randomUUID(); log.trace("[{}] Processing provision publish msg [{}]!", sessionId, exchange.advanced().getRequest()); @@ -195,7 +195,7 @@ public class CoapTransportResource extends AbstractCoapTransportResource { private void processRequest(CoapExchange exchange, SessionMsgType type) { log.trace("Processing {}", exchange.advanced().getRequest()); - exchange.accept(); + deferAccept(exchange); Exchange advanced = exchange.advanced(); Request request = advanced.getRequest(); @@ -346,6 +346,16 @@ public class CoapTransportResource extends AbstractCoapTransportResource { new CoapNoOpCallback(exchange)); } + /** + * Send an empty ACK if we are unable to send the full response within the timeout. + * If the full response is transmitted before the timeout this will not do anything. + * If this is triggered the full response will be sent in a separate CON/NON message. + * Essentially this allows the use of piggybacked responses. + */ + private void deferAccept(CoapExchange exchange) { + transportContext.getScheduler().schedule(exchange::accept, 500, TimeUnit.MILLISECONDS); + } + private UUID toSessionId(TransportProtos.SessionInfoProto sessionInfoProto) { return new UUID(sessionInfoProto.getSessionIdMSB(), sessionInfoProto.getSessionIdLSB()); }