The existing checkpoint code doesn't accommodate single large accumulator state larger than 128MB. In Atlas stream processing, the maximum size for a single large accumulator stat is 1GB. We need to add support for checkpointing these large states. 

https://github.com/10gen/mongo/blob/a01f7c5fd62674c1bbc5531ae35f23b007690cad/src/mongo/db/modules/enterprise/src/streams/exec/checkpoint/local_disk_checkpoint_storage.cpp#L118

https://github.com/10gen/mongo/blob/a01f7c5fd62674c1bbc5531ae35f23b007690cad/src/mongo/db/modules/enterprise/src/streams/exec/checkpoint/local_disk_checkpoint_storage.h#L32