[email protected]: Uncaught Cannot read properties of undefined (reading 'closeResultSet')

[PierreFritsch]

Hi folks

While checking our logs for application crashes, we stumbled upon a null pointer exception in the hdb module:

Uncaught Cannot read properties of undefined (reading 'closeResultSet')

The stack trace points to ResultSet:

  this._connection.closeResultSet({
    resultSetId: this.id
  }, done);

We cannot provide further hints on how to reproduce for the time being, maybe this information is already sufficient to check if this function needs further checks or a different error handling?

We suspect that the exception might be related to a DB pool being drained by another process, as our logs contain the following error message approx. 100ms earlier:

Acquiring client from pool timed out. Please review your system setup, transaction handling, and pool configuration. Pool State: borrowed: 10, pending: 0, size: 10, available: 0, max: 10

Stack Trace

TypeError: Cannot read properties of undefined (reading 'closeResultSet'),
at ResultSet.sendClose (/home/vcap/app/node_modules/hdb/lib/protocol/ResultSet.js:299:20),
at callEmitEndAndClose (/home/vcap/app/node_modules/hdb/lib/protocol/ResultSet.js:153:15),
at /home/vcap/app/dynatrace/oneagent/agent/bin/
1.299.50.20240930-123825/any/nodejs/nodejsagent.js:2273:48,
at t.runInContext (/home/vcap/app/dynatrace/oneagent/agent/bin/1.299.50.20240930-123825/any/
nodejs/nodejsagent.js:2384:24),
at callEmitEndAndClose (/home/vcap/app/dynatrace/oneagent/agent/bin/1.299.50.20240930-123825/any/nodejs/nodejsagent.js:2
273:18),
at process.processTicksAndRejections (node:internal/process/task_queues:77:11)

Version Information

npm ls hdb
├─┬ @sap/[email protected]
│ └─┬ @sap/[email protected]
│   ├─┬ @sap/[email protected]
│   │ └── [email protected] deduped
│   └── [email protected]
├─┬ @sap/[email protected]
│ └── [email protected] deduped
├─┬ @sap/[email protected]
│ └─┬ @sap/[email protected]
│   ├─┬ @sap/[email protected]
│   │ └── [email protected] deduped
│   └── [email protected] deduped

[PierreFritsch]

CC @jan-philip-zieher FYI

[jan-philip-zieher]

One sidemark to reproduce, we did something like this:

execute() {
 this._connection.init();
 spawn({ tenant: this.request.tenant, user: this.request.user, id: correlationId }, async () => {
  doDbActions(this._connection);
 });
}

and execute() was triggered multiple times at the same time

[IanMcCurdy]

Thanks for raising this issue. I've discovered that calling ResultSet.close() multiple times on the same object can reproduce this error. Is it possible that your application is doing this? Regardless, we will fix this issue and add appropriate error handling for this case, but perhaps you can fix it on your side in the meantime.

Thanks,
Ian