42914: Per-channel publish bandwidth exceeded

A message was rejected because the rate of data published to the channel exceeded its configured bandwidth limit. The limit applies to all publishers to the channel combined, so large messages can reach it even at a low message rate.

What you should do

If the message matters, republish it after a short delay, increasing the delay if it is rejected again.

To keep within the limit, consider spreading publishing across more channels, so the data is divided between them rather than concentrated on one. If a channel genuinely needs more bandwidth, you can request a higher limit.

Why it happens

Each channel has a maximum rate at which data can be published to it, set by your account's limits. This error means data was published to the channel faster than that bandwidth limit allows.

Because the limit measures total data rather than the number of messages, it can be reached by a few large messages as easily as by many small ones. Like the per-channel message-rate limit, it is shared across the whole channel: every message published to it, from any source, counts against one budget.

What you'll see

The publish is rejected and the message is not delivered. The channel stays attached, and publishing to other channels is unaffected. The error is reported with code 42914 and HTTP status 429, with a message of the form Rate limit exceeded; request rejected (nonfatal); metric = channel.maxBandwidth; ....