AgentFixboard
UnverifiedLast checked Mastra#transport#error-messages

UpstashTransport silently drops batches when Redis rejects a pipeline command

UpstashTransport reports a successful flush when Redis rejects LPUSH inside an HTTP 200 pipeline. The batch is already gone from logBuffer, so the records are lost. The linked issue does not give a user-facing error string.

From GitHub

mastra-ai/mastra

IssuePull request

Difficulty
Easy
Time
~5 min
Steps
2
Fixed in
—
Last checked

Unverified: we could not confirm from the sources that a fix shipped. Source: PR #27480 merged. Last checked 2026-10-19.

Symptom

UpstashTransport reports a successful flush when Redis rejects LPUSH inside an HTTP 200 pipeline. The batch is already gone from logBuffer, so the records are lost. The linked issue does not give a user-facing error string.

Evidence what you'll see

  • The mocked pipeline body is [{ error: 'WRONGTYPE Operation against a key holding the wrong kind of value' }, { error }]. After _flush(), logBuffer.length is 0 and there is no thrown error.
  • Upstash's pipeline format returns one result or error object per command. Checking only response.ok does not establish that the logs were written.
  • The final destroy callback also reports success for these rejected writes.

Why it happens

The transport treated every HTTP-successful pipeline as a successful write. Pull request 27480 fails the flush when LPUSH is rejected, puts the batch back on the buffer for retry, and does not advance lastFlush. A rejected LTRIM after a successful push is reported without re-sending the batch.

Affected versions

@mastra/loggers workspace source 1.3.9-alpha.0. Node.js 24.21.0, pnpm 11.21.0, Linux. The reproduction mocks fetch; no live Redis is required.

Fix steps

0 of 2 done

Your check marks stay in this browser only.

How to check it worked

  • When the pipeline returns a WRONGTYPE error on LPUSH, _flush() rejects, the record stays in logBuffer, and destroy does not report success for that batch.

If it still fails

  • No published release tag contains pull request 27480. Tag @mastra/core@1.78.0 was compared against merge 4d7d50fcface and does not contain it.
  • A rejected LTRIM after a successful LPUSH is not re-sent, so those records are not duplicated.

Sources and credit

Summarized in our own words from these public reports. Credit goes to their authors.

Provided as is, without warranty. Try changes in a non-production environment and back up first. Security-related steps: verify against the official docs. Terms · Request removal or attribution change

Hit an error we don't cover? Submit it