RunReveal June 9th BYODB incident
RunReveal deployed a change on June 9th to help our "bring your own databases" customers more easily manage database migrations. This change allows customers to automatically update their databases, choose when to apply migrations, and not need to rely on the RunReveal team to keep their schemas up to date.
Unfortunately there was a subtle bug that caused data delays for object storage and API polling sources, and data loss for webhook sources that do not retry failed requests.
What was the bug
Our Bring your own database destinations have a variety of settings associated with them. These settings tell us how large the batch sizes should be that we write to their databases, what the flush frequency should be if the batch size is not reached, if we should connect with custom headers, etc.
As part of this change the settings object was rewritten to have additional context and the format of the FlushDuration was subtly changed. When we read the flush duration we can have two separate formats of it. The first is a human readable string like 30s, and the second is in Integer milliseconds like 30000 due to how Javascript represents timestamps.
We accidentally left the JSON Marshaling logic unimplemented for the Flush Duration in this settings object (which will default to nanoseconds), and the custom FlushDuration while unmarshalling treated this number as milliseconds.
This meant that the Flush Duration was significantly longer that expected by a huge factor. This meant that smaller sources that relied on this flush duration were essentially never being synced.
Below is the fix we implemented that got the Flush timeout into the format that it was expected to be in:
@@ -69,26 +69,31 @@ types/destinations.go
type Duration time.Duration
func (d *Duration) UnmarshalJSON(b []byte) error {
var s string
if err := json.Unmarshal(b, &s); err != nil {
// fallback to int milliseconds for compatibility with old code
var i int
if err2 := json.Unmarshal(b, &i); err2 == nil {
*d = Duration(time.Duration(i) * time.Millisecond)
return nil
}
return err
}
t, err := time.ParseDuration(s)
if err != nil {
return err
}
*d = Duration(t)
return nil
}
+func (d Duration) MarshalJSON() ([]byte, error) {
+ t := time.Duration(d)
+ return json.Marshal(t.String())
+}
What was the impact of this issue
This issue only impacted customers using bring your own database configurations. Sources we read from object storage and sources we poll APIs for, that data was delayed during this incident. However data we received from webhooks was lost between 2025-06-09T18:40:00Z and 2025-06-10T01:00:00Z for impacted customers.
With sources we receive an HTTP request (Webhook) from, these sources lost data during the time window of 6 hours if they did not retry their requests when the API service was restored. We are deeply sorry about this. We believe that RunReveal going down or having operational issues shouldn't cause data loss for our customers and we're working on that being true.
What are we doing about this
There are two key areas we can improve from this incident.
The work required to improve the resilience of webhook sources is very straightforward and well-scoped so we expect to start working on this problem in the next few weeks.
Follow up questions
If you have follow up questions feel free to reach out to evan@ and alan@ and we'd be happy to walk you through the bug, the metrics we have on the incident, and our plans to make RunReveal even more resilient.