sow: Content from Server

The sow message returns a record from the SOW. For more information, see the State of the World (SOW) Topics and Querying the State of the World (SOW) chapters in the AMPS User Guide.

Header Fields

The following table contains the header fields returned in a sow message:

Field	Description
Command	Type of message. Always sow, as encoded by the protocol.
Topic	The topic from which the records were produced.
SowKey	An AMPS-created identifier for this message.
BatchSize	The number of records returned in a single sow batch.
Timestamp	The time at which AMPS generated this message.
QueryId	The QueryId of the query that produced this message.
MsgLen	The length of the first SOW message in the data portion of this message.

Data

The sow message contains data. The data for the message consists of up to BatchSize messages, formatted as expected by the protocol. Each message contains its own header, with the following fields:

Field	Description
SowKey	An AMPS-created identifier for this message.
CorrelationId	A user-provided string that will be passed, verbatim, to subscribers. If this header is not present on the SOW record, subscribers receive no value for the CorrelationId. The contents of this header must consist of characters that are legal in Base64 encoding.
MsgLen	The length of the next SOW message in the data portion of this message.