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Notas
Notas are Pronghorns alternative to Java annotations. We chose this approach because it avoids reflection while still providing readability. Notas allow you to “tag” your stage to modify their behavior or appearance. Please note that notas can have unexpected side effects and should be applied carefully.
Notas are always defined in the constructor of your stage. They should not be defined in
startup() or any other place in your class.Some common nota definitions are listed here:
Name | Description | Example |
SCHEDULE_RATE | Specify the delay between calls regardless of how long call takes in nanoseconds. | GraphManager.addDefaultNota(gm, GraphManager.SCHEDULE_RATE, 500); |
MONITOR | Used to tag internal stages. Do not use. | |
PRODUCER | Tag your stage as a producer. Usually, producing stages are automatically detected, but use this nota if the producer is expecting a response from another stage. | GraphManager.addNota(gm, GraphManager.PRODUCER, GraphManager.PRODUCER, this); |
STAGE_NAME | Give a custom name to a stage. | GraphManager.addNota(graphManager, GraphManager.STAGE_NAME, "CustomStageName", this); |
SLA_LATENCY | Define a custom Service Level Agreement in milliseconds. If your stage takes longer than this, a warning will appear. | GraphManager.addNota(graphManager, GraphManager.SLA_LATENCY, 100_000_000, this); |
LOAD_BALANCER | Even splits traffic across outputs for your stage. | GraphManager.addNota(graphManager, GraphManager.LOAD_BALANCER, GraphManager.LOAD_BALANCER, this); |
LOAD_MERGE | Consume equal priority traffic from inputs for your stage. | GraphManager.addNota(graphManager, GraphManager.LOAD_MERGE, GraphManager.LOAD_MERGE, this); |
HEAVY_COMPUTE | Tag your stage as "Heavy compute". The scheduler will avoid putting any stages tagged with this onto the same thread. | GraphManager.addNota(graphManager, GraphManager.HEAVY_COMPUTE, GraphManager.HEAVY_COMPUTE, this); |
TRIGGER | Limit rate or flow and triggers other stages. | |
ROUTER_HUB | Tag your stage as a potential bottleneck for traffic. | |
ISOLATE | Isolate your stage from its neighbors and put it on its own thread. | GraphManager.addNota(graphManager, GraphManager.ISOLATE, GraphManager.ISOLATE, this); |
DOT_RANK_NAME | Stages with the same name as defined here will be put next to each other on the graph. | GraphManager.addNota(gm, GraphManager.DOT_RANK_NAME, "SocketReader", socketReaderStage); |
DOT_BACKGROUND | Define a custom stage background color for telemetry. | GraphManager.addNota(graphManager, GraphManager.DOT_BACKGROUND, "lavenderblush", this); |
UNSCHEDULED | Will not execute run() on this stage, only startup() and shutdown(). | GraphManager.addNota(graphManager, GraphManager.UNSCHEDULED, GraphManager.UNSCHEDULED, this); |
THREAD_GROUP | Used to tag internal stages and track behavior. Do not use. | |
A stage constructor with a custom background color in the telemetry can look like this:
public BMPDumperStage(GraphManager graphManager, Pipe<JPGSchema> input, boolean verbose, boolean time) {
super(graphManager, input, NONE);
this.input = input; // Use GraphManager to add a background nota to the current stage. "this" refers to the current stage.
GraphManager.addNota(graphManager, GraphManager.DOT_BACKGROUND, "red", this);
}
Last modified 5yr ago