BUG: [ Error: transaction [SVR_01:PKT00517] resolverFunction is type undefined ]

[dsriseah]

Original thread is in this slack thread.

• proxy errors on management screen
• on P4 school network (teachers)
• happening to everyone (students, teachers, joshuas)

PROXY LOG EXCERPT nc-multiplex/log.txt

NC_MUX   - 2025/09/02 TUE 18:34:46 >>> proxying request /graph/2025ELAFigurativeDevicesP5:8080 to :3009 (client ::ffff:127.0.0.1)
ServerDB - AUTOSAVING! 29 NODES / 13 EDGES / 0 COMMENTS / 0 READBY <3
ServerDB - AUTOSAVING! 25 NODES / 9 EDGES / 1 COMMENTS / 0 READBY <3
/root/nc-multiplex/netcreate-itest/app/unisys/common-netmessage-class.js:360
      throw Error(
            ^

Error: transaction [SVR_01:PKT00517] resolverFunction is type undefined
    at NetMessage.CompleteTransaction (/root/nc-multiplex/netcreate-itest/app/unisys/common-netmessage-class.js:360:13)
    at m_HandleMessage (/root/nc-multiplex/netcreate-itest/app/unisys/server-network.js:300:9)
    at m_SocketMessage (/root/nc-multiplex/netcreate-itest/app/unisys/server-network.js:285:9)
    at WebSocket.<anonymous> (/root/nc-multiplex/netcreate-itest/app/unisys/server-network.js:186:5)
    at WebSocket.emit (node:events:517:28)
    at Receiver.ontext (/root/nc-multiplex/netcreate-itest/node_modules/ws/lib/WebSocket.js:841:10)
    at /root/nc-multiplex/netcreate-itest/node_modules/ws/lib/Receiver.js:536:18
    at /root/nc-multiplex/netcreate-itest/node_modules/ws/lib/Receiver.js:368:7
    at /root/nc-multiplex/netcreate-itest/node_modules/ws/lib/PerMessageDeflate.js:249:5
    at afterWrite (node:internal/streams/writable:500:5)

LOG EXCERPT

ServerDB - AUTOSAVING! 27 NODES / 9 EDGES / 0 COMMENTS / 0 READBY <3
ServerDB - RequestEditLock: edge added to open editors
ServerDB - AUTOSAVING! 27 NODES / 9 EDGES / 0 COMMENTS / 0 READBY <3
/root/nc-multiplex/netcreate-itest/app/unisys/common-netmessage-class.js:360
Error: transaction [SVR_01:PKT00650] resolverFunction is type undefined

---
ServerDB - RequestEditLock: edge added to open editors
ServerDB - AUTOSAVING! 27 NODES / 19 EDGES / 0 COMMENTS / 0 READBY <3
/root/nc-multiplex/netcreate-itest/app/unisys/common-netmessage-class.js:360
Error: transaction [SVR_01:PKT04902] resolverFunction is type undefined

---
SRV_NET  - socket DEL UADDR_11 from network
SRV_NET  - socket DEL UADDR_09 from network
/root/nc-multiplex/netcreate-itest/app/unisys/common-netmessage-class.js:360
Error: transaction [SVR_01:PKT00070] resolverFunction is type undefined

---
ServerDB - RequestEditLock: node added to open editors
ServerDB - AUTOSAVING! 27 NODES / 20 EDGES / 0 COMMENTS / 0 READBY <3
/root/nc-multiplex/netcreate-itest/app/unisys/common-netmessage-class.js:360
Error: transaction [SVR_01:PKT00163] resolverFunction is type undefined

[dsriseah]

Sri Commentary:

The error being thrown triggers when a transaction packet is received that is missing a resolver function, which should be impossible on a stable network. The error says it is type 'undefined', meaning that the resolver function that matches the packet's ID is missing.

Background:

NetCreate implements common-netmessage-class.js for both the server and the client to use packets for sending message. We implement a special message called Call which will allow a message request to be returned to the originating caller across the network asynchronously without crosstalk. The client uses client-messager-class as its API, whereas the server uses server-network.js as the API. They both use the common-netmessage-class.

The error is originating on the server, meaning it must be happening there. The log indicates that the error is in common-netmessage-class.js in CompleteTransaction, which itself is being called by the server-side message handler in server-network's m_HandleMessage() client dispatcher.

The returning packet is likely being received from a client. To find whether it is a specific network message, we want to log the contents of the packet itself, which has several built-in logging features, notably

• id which is created by the originating endpoint
• s_uaddr which is the address of the creating endpoint
• seqlog which notes the hop chain of the transaction

CODE ENHANCEMENTS TO TRAP THIS INFO

add to common-netmessage-class.js before CompleteTransaction method

  /// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
  /** Utility to check whether a transaction packet has a valid resolver
   *  function */
  HasTransactionHash() {
    var hash = m_GetHashKey(this);
    var resolverFunc = m_transactions[hash];
    return typeof resolverFunc === 'function';
  }

replace server-network.js in the m_HandleMessage() method

  // is this a returning packet that was forwarded?
  if (pkt.IsOwnResponse()) {
    // console.log(PR,`-- ${pkt.Message()} completing transaction ${pkt.seqlog.join(':')}`);
    pkt.CompleteTransaction();
    return;
  }

with

  // is this a returning packet that was forwarded?
  if (pkt.IsOwnResponse()) {
    // console.log(PR,`-- ${pkt.Message()} completing transaction ${pkt.seqlog.join(':')}`);
    if (pkt.HasTransactionHash()) pkt.CompleteTransaction();
    else {
      LOGGER.WriteRLog(`ERROR: Packet ${pkt.id} '${pkt.msg}' transaction error`);
      LOGGER.WriteRLog(pkt.JSON());
    }
    return;
  }

[benloh]

I believe hash needs to be defined in HasTransactionHash?

  HasTransactionHash() {
    const hash = m_GetHashKey(this); // <== add hash here!
    var resolverFunc = m_transactions[hash];
    return typeof resolverFunc === 'function';
  }

[dsriseah]

Other comments

• This is an unusual error, as there should be no case where the packet hash should be missing for an originating packet
• The original netmessage protocol was designed for a single instance running where it could be assumed that there was a single server address (SRV01) generating its own packet ids.

Since proxying was hacked on to the server, it is possible that the assumptions above break. There are some conditions that would make this possible

• there are/were two server instances running resolving to the same proxy
• AND the servers are receiving packets that are not originating from it due to proxy rules
• AND the servers somehow retain client connections (?)

[dsriseah]

I believe hash needs to be defined in HasTransactionHash?

  HasTransactionHash() {
    const hash = m_GetHashKey(this); // <== add hash here!
    var resolverFunc = m_transactions[hash];
    return typeof resolverFunc === 'function';
  }

Yep!

[kalanicraig]

Have a little more detail on the errors from the teacher: "Teacher reported issues with commenting. She shared that when students save their comment, it freezes up their computer. They have to shut down and when they return to Net.Create there is an error message." Digital Promise team member asked teacher to take a photo of the error message and to send time it happened and the token of the student experiencing the issue so we can track.