bug(remote_write): Fix compression buffer pooling (#1889)

fpetkovski · web-flow · commit 6886445d7cb4 · 2025-10-07T16:11:24.000+01:00
The compressed buffer is released before the request is made, which leads
to corrupted remote-write payloads being sent to the target.

Signed-off-by: Filip Petkovski &lt;filip.petkovsky@gmail.com&gt;
diff --git a/exp/api/remote/remote_api.go b/exp/api/remote/remote_api.go
@@ -242,7 +242,7 @@ func (r *API) Write(ctx context.Context, msgType WriteMessageType, msg any) (_ W
 		return WriteResponseStats{}, fmt.Errorf("compressing %w", err)
 	}
 	r.bufPool.Put(buf)
-	r.bufPool.Put(comprBuf)
+	defer r.bufPool.Put(comprBuf)
 
 	// Since we retry writes we need to track the total amount of accepted data
 	// across the various attempts.

Original file line number	Diff line number	Diff line change
`@@ -242,7 +242,7 @@ func (r *API) Write(ctx context.Context, msgType WriteMessageType, msg any) (_ W`
`242`	`242`	`return WriteResponseStats{}, fmt.Errorf("compressing %w", err)`
`243`	`243`	`}`
`244`	`244`	`r.bufPool.Put(buf)`
`245`		`- r.bufPool.Put(comprBuf)`
	`245`	`+ defer r.bufPool.Put(comprBuf)`
`246`	`246`
`247`	`247`	`// Since we retry writes we need to track the total amount of accepted data`
`248`	`248`	`// across the various attempts.`