RangeError: Invalid array length crashes the worker when the byte range matrix pulls a compressed block that blows past the buffer limit. The GET request hits /api/v2/media/recordings/{id}/chunks with this payload { "chunkSize": 5242880, "format": "mp3", "compressed": true }, but the stream schema validation rejects the size before the checksum pipeline runs. Latency spiked on the webhook callback. We’re trying to expose the streamer for automated management and the codec consistency check is failing on the resume trigger.
Node.js 18.17
Chunk size capped at 5MB
Gzip compression enabled
Byte range matrix validated against storage constraints
{ "chunkSize": 1048576, "format": "wav", "compressed": false, "streaming": true } NICE CXone Studio SDK allocates the buffer directly, so dropping compressed to false and capping chunkSize at 1048576 stops the schema validation from rejecting the payload. The RangeError hits because the worker tries to build a contiguous heap block for the whole compressed matrix before the checksum pipeline even starts. Switching to streaming: true forces the runtime to process chunks asynchronously instead of blocking the event loop. It’s easier to drop the compression flag than fight the heap limit. Don’t push past the buffer cap.
Memory leaks out fast if you ignore the allocation cap. Heap fills up weirdly. Keep the matrix small. The REST Proxy action needs the Accept: application/octet-stream header set manually, otherwise the gateway drops the connection mid-pull. Gateway drops the packet anyway if the queue isn’t flushed.
You’re spot on about the heap allocation, but running this in Lambda means you’ll still hit the memory ceiling if you don’t stream it properly. Just swap the request body to this:
The suggestion above regarding the streaming: true flag aligns with how the system handles media streams. When compressed stays enabled, the service tries to assemble the full matrix in memory first. That’s what triggers the buffer overflow.
To prevent the worker from choking on the event loop, the payload requires a few adjustments. According to the Resource Center article on Fetching Recording Chunks, uncompressed WAV streams must be piped directly to a sink without intermediate buffering.
Recommended configuration:
Set chunkSize to 1048576 or lower
Disable compressed to avoid heap fragmentation
Enable streaming to bypass the validation timeout
Pipe the response to a fs.createWriteStream immediately
A common workaround for constrained environments is to offload the chunk assembly to a separate worker process. This keeps the execution memory under the ceiling. The API documentation also notes that the byteRange header should be omitted when streaming is active, otherwise the service returns a 400 error.
Is the callback webhook configured to handle partial responses, or does it expect a complete payload before acknowledging? The retry logic usually needs adjustment when the stream breaks into smaller s. Leaving the validation timeout at the default often causes the connection to drop. The final chunk just gets lost. Happens more often than the documentation suggests.
Swapped the payload to match the streaming flag and capped the chunk size.
The buffer overflow vanished completely. It’s routing the chunks straight to the sink now.