Observe request timeout - Leshan Server

Hello,

I have been dealing with an issue on the server for the past two days. I have built my own LWM2M Server and I use your leshan-client-demo as “device”. My Java version is 11 and the leshan-server-cf is 1.3.1. Everything works as expected when I test it locally (Ubuntu 20). The client is able to register with the server over DTLS. Upon registration the server sends an Observe Request to the client. Code snippet below: However, in the scenario where my server is on AWS instance (Ubuntu 16) and the client is running on my laptop. The Observe Request timeouts and my client doesn’t receive it. Some logs below:

java[29570]: 14:43:59.468 [CoapServer(main)#1] DEBUG org.eclipse.leshan.core.californium.CoapSyncRequestObserver - Synchronous request cancelled CON-GET    MID=   -1, Token=null, OptionSet={"Observe":0, "Uri-Path":["3","0"], "Accept":"application/vnd.oma.lwm2m+json"}, canceled no payload
java[29570]: 14:43:59.468 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.stack.ReliabilityLayer - Exchange[L10] send request, failed transmissions: 0
java[29570]: 14:43:59.468 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.stack.ReliabilityLayer - Exchange[L10] prepare retransmission for CON-GET    MID=   -1, Token=null, OptionSet={"Observe":0, "Uri-Path":["3","0"], "Accept":"application/vnd.oma.lwm2m+json"}, canceled no payload
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.BaseMatcher - registering observe request CON-GET    MID=26251, Token=null, OptionSet={"Observe":0, "Uri-Path":["3","0"], "Accept":"application/vnd.oma.lwm2m+json"}, canceled no payload
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.InMemoryMessageExchangeStore - [LWM2M Server-coaps://] Exchange[L10] added with KeyMID[{my_ip}}:4678-26251], CON-GET    MID=26251, Token=B7BA9A3D0EF424D0, OptionSet={"Observe":0, "Uri-Path":["3","0"], "Accept":"application/vnd.oma.lwm2m+json"}, canceled no payload
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.InMemoryMessageExchangeStore - [LWM2M Server-coaps://] Exchange[L10] added with token KeyToken[B7BA9A3D0EF424D0], CON-GET    MID=26251, Token=B7BA9A3D0EF424D0, OptionSet={"Observe":0, "Uri-Path":["3","0"], "Accept":"application/vnd.oma.lwm2m+json"}, canceled no payload
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.UdpMatcher - tracking open request [KeyMID[{my_ip}}:4678-26251], KeyToken[B7BA9A3D0EF424D0]]
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.Exchange - Exchange[L10, complete]!
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.InMemoryMessageExchangeStore - [LWM2M Server-coaps://] removing Exchange[L10, complete] for token KeyToken[B7BA9A3D0EF424D0]
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.InMemoryMessageExchangeStore - [LWM2M Server-coaps://] removing Exchange[L10, complete] for MID KeyMID[{my_ip}}:4678-26251]
java[29570]: 14:43:59.469 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.Exchange - local Exchange[L10, complete] completed CON-GET    MID=26251, Token=B7BA9A3D0EF424D0, OptionSet={"Observe":0, "Uri-Path":["3","0"], "Accept":"application/vnd.oma.lwm2m+json"}, canceled no payload!
java[29570]: 14:43:59.470 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.deduplication.SweepDeduplicator - add exchange for KeyMID[{my_ip}}:4678-45544]
java[29570]: 14:43:59.470 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.deduplication.SweepDeduplicator - found exchange for KeyMID[{my_ip}}:4678-45544]
java[29570]: 14:43:59.470 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.deduplication.SweepDeduplicator - found exchange for KeyMID[{my_ip}}:4678-45544]
java[29570]: 14:43:59.470 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.deduplication.SweepDeduplicator - found exchange for KeyMID[{my_ip}}:4678-45544]
java[29570]: 14:43:59.470 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.deduplication.SweepDeduplicator - found exchange for KeyMID[{my_ip}}:4678-45544]
java[29570]: 14:43:59.470 [CoapServer(main)#1] DEBUG org.eclipse.leshan.server.registration.RegistrationHandler - Updated registration org.eclipse.leshan.server.registration.UpdatedRegistration@460640 by RegistrationUpdate [registrationId=3VgTvlBbQ8, identity=Identity /{my_ip}}:4678[x509=darko], lifeTimeInSec=null, smsNumber=null, bindingMode=null, objectLinks=null]
java[29570]: 14:43:59.471 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.stack.ReliabilityLayer - Exchange[R11] send response null-2.04   MID=   -1, Token=null, OptionSet={}, no payload, failed transmissions: 0
java[29570]: 14:43:59.471 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.Exchange - Exchange[R11, complete]!
java[29570]: 14:43:59.471 [CoapServer(main)#1] DEBUG org.eclipse.californium.core.network.Exchange - Remote Exchange[R11, complete] completed ACK-2.04   MID=45544, Token=B0357A177E9B7825, OptionSet={}, no payload!
java[29570]: device is still here: darko

Some more tests that were done:

• I tested your leshan-server-demo on AWS with UDP. Everything works fine, my client receives data.
• Modified the leshan-server-demo to match the functionality of my lwm2m server. (What I mean by functionality is calling the above onRegistered function from the RegistrationListener) It still fails.
• I ran the demo client on the AWS instance, too. My lwm2m server fails to send data again. Even though, the client runs on the same instance.

If something is not clear, let me know. 😃 Thanks

[darkopoppin]

I will do it myself to save you a few clicks. 😄

[sbernard31]

Thanks for the explanation.

You’re welcome.

Sorry about the image

No problem 😉

Glad we find a solution and probably an explanation for you issue. Should we close it now ?