Hands-On Software Engineering with Golang

Establishing protocol buffer definitions for master payloads

Now, let's take a look at the protocol buffer definition for the payloads sent by the master to the individual workers:

message MasterPayload {  oneof payload {    JobDetails job_details = 1;    Step step = 2;    RelayMessage relay_message = 3;  }}

When a worker connects to the job queue, it blocks until the master assigns it a new job by sending out a JobDetails message:

message JobDetails {  string job_id = 1;  google.protobuf.Timestamp created_at = 2;    // The [from, to) UUID range assigned to the worker. Note that from is   // inclusive and to is exclusive.  bytes partition_from_uuid = 3;  bytes partition_to_uuid = 4;}

The job_id field contains a unique ID for the job to be executed while ...