How do I feed long JSON documents via UDP?

[pavel-kirienko]

I need to feed a sequence of long JSON messages, several KiB each, via the UDP server, but I am unable to do that because I think nc breaks my message into 1 KiB chunks (1024 bytes) which results in an "unexpected end of input" error:

Problem parsing the message. UDP Server will be stopped.
[json.exception.parse_error.101] parse error at line 1, column 1025: syntax error while parsing object - unexpected end of input; expected '}'

I am using it as follows:

my_command | nc -u localhost 9870

my_command outputs large newline-separated JSON dicts. Here's one (it is a perfectly valid JSON dict):

{"1030":{"_meta_":{"ts_system":1713128556.959323,"ts_monotonic":302431.128461,"source_node_id":4010,"transfer_id":3108,"priority":"nominal","dtype":"zubax.primitive.real32.Vector4VarTs.1.0"},"value":{"timestamp":{"microsecond":1713128556932304},"value":{"value":[18933.865234375,9.68315315246582,0.0,40378.70703125]}},"covariance_urt":[1957.89404296875,1062.9013671875,0.0,0.0,1845.5074462890625,0.0,0.0,1464034394112.0,0.0,422114689024.0]},"1031":{"_meta_":{"ts_system":1713128556.959048,"ts_monotonic":302431.128185,"source_node_id":4010,"transfer_id":3108,"priority":"nominal","dtype":"zubax.primitive.real32.ScalarVarTs.1.0"},"value":{"timestamp":{"microsecond":1713128556932304},"value":{"value":18933.865234375}},"error_variance":1957.89404296875},"1032":{"_meta_":{"ts_system":1713128556.959095,"ts_monotonic":302431.128233,"source_node_id":4010,"transfer_id":3108,"priority":"nominal","dtype":"zubax.primitive.real32.ScalarVarTs.1.0"},"value":{"timestamp":{"microsecond":1713128556932304},"value":{"value":9.68315315246582}},"error_variance":1845.5074462890625},"1033":{"_meta_":{"ts_system":1713128556.959991,"ts_monotonic":302431.129129,"source_node_id":4010,"transfer_id":3108,"priority":"nominal","dtype":"zubax.primitive.real32.ScalarVarTs.1.0"},"value":{"timestamp":{"microsecond":1713128556932304},"value":{"value":0.0}},"error_variance":1464034394112.0},"1034":{"_meta_":{"ts_system":1713128556.959821,"ts_monotonic":302431.128959,"source_node_id":4010,"transfer_id":3108,"priority":"nominal","dtype":"zubax.primitive.real32.ScalarVarTs.1.0"},"value":{"timestamp":{"microsecond":1713128556932304},"value":{"value":40378.70703125}},"error_variance":422114689024.0}}

How do I make the UDP server wait for newline before attempting to parse the message? Or am I misunderstanding the nature of the problem?