Missing parked message content when reading parked messages stream from Go Client

[fedemoya]

I’m running EventStore version 24.10. I’m using the Go client to connect to the server.

I’m writing an unhappy path integration test in which a service consumes a message from ESDB, fails to process it, and parks it.

From the test, I want to check that the message was parked and I also want to check that the parked message is the one I expected. To do this I use the go client to read from the corresponding parked message stream, which in my case is $persistentsubscription-testStream::testGroup-parked".

When I read from the stream I get the following event (the screenshot below is from my IDE debugger)

The problem is that the event doesn’t contain the parked message content. The Data field only contains

0@testStream

and the UserMetadata field contains

{
  "added": "2025-03-14T10:43:38.2933966+00:00",
  "reason": "Client explicitly NAK'ed message.\ni dont like this message"
}

If I checked in the Admin UI I can see the parked message content which is

{
  "thisIsA": "rawTestEvent"
}

Why did this happen? Is this an issue with the Go client?

[yves.reynhout]

Hi,

Could you provide details of how you are reading that parked message stream? Are you familiar with link-to events? I’m going to assume that ResolveLinkTos is not set to True.

[yves.lorphelin]

It’s the way the database works, remember we’re an append-only immutable store.

We don’t “move” the events to a special queue or streams from the subscriptions : we point to it.

What you’re seeing in your read operation is a linkto event : essentially a pointer to another event
0@testStream means Event number 0 of testStream

If you want to read the parked message and have both the linkto & the linked to event you need to set ResolveLinkTos : true

Catch-up subscriptions

Here’s a table summarizing what is where in the resolved_event

When facing a…	ResolveLink	Event	Link	OrginalEvent
regular event	true	the event	null	the event
regular event	false	the event	null	the event
link event	true	the event pointed by the link	the link itself	the link
link event	false	the link	null	the link
link event (pointing to a deleted event)	true	null	the link	the link
link event (pointing to a deleted event)	false	the link	null	the link

[fedemoya]

Thank you guys for the quick replay and for the explanation. Indeed, ResolveLinkTos: true, was the option I was missing when reading from the stream. With that option set to true I was able to read the parked message.