Aether

Monitoring for the Aeron messaging system.

Usage

An instance of the Aether client reads counters from one or more Aeron MediaDrivers, and publishes the counter data to a collector. The collector's function is to build a system-wide view of the Aeron message flows, matching publishers to subscribers.

Running an Aether Collector

// launch a MediaDriver for publishing countersfinalMediaDriverdriver = MediaDriver.launchEmbedded(newMediaDriver.Context()
.threadingMode(ThreadingMode.SHARED)
.sharedIdleStrategy(newSleepingMillisIdleStrategy(1L)));
// create a publish that will send out counter snapshotsfinalCounterSnapshotPublishersnapshotPublisher = newCounterSnapshotPublisher(
newCounterSnapshotPublisher.Context()
.aeronDirectoryName(driver.aeronDirectoryName()));
// create an Aether agent that will periodically read and publish the countersfinalAetheraether = Aether.launch(newAether.Context()
.monitoringLocations(Collections.singletonList(
newAether.MonitoringLocation("default", "/path/to/monitored-media-driver")))
.counterSnapshotListener(snapshotPublisher)
.aeronDirectoryName(driver.aeronDirectoryName())
.threadingMode(Aether.ThreadingMode.THREADED));

Running an Aether Aggregator

// create a MediaDriver to receive counter snapshotsfinalMediaDrivermediaDriver = MediaDriver.launchEmbedded(newMediaDriver.Context()
.threadingMode(ThreadingMode.SHARED)
.sharedIdleStrategy(newSleepingMillisIdleStrategy(1L)));
// create a subscription to deserialise received snapshotsfinalCounterSnapshotSubscribercounterSnapshotSubscriber =
newCounterSnapshotSubscriber(newCounterSnapshotSubscriber.Context()
.aeronDirectoryName(mediaDriver.aeronDirectoryName())
.counterSnapshotListener(newConsolePrinter()));
// poll subscription to update system snapshotcounterSnapshotSubscriber.doWork();

Output

The default ConsolePrinter will display aggregate information for all configured contexts:

-----------------------------------------
===== System counters for "server" =====
Bytes sent: 0
Bytes received: 27584
NAKs sent: 0
NAKs received: 0
Errors: 0
Client timeouts: 0
===== System counters for "client" =====
Bytes sent: 27584
Bytes received: 0
NAKs sent: 0
NAKs received: 0
Errors: 0
Client timeouts: 0
===== Monitoring 3 channels =====
==== aeron:udp?endpoint=localhost:54567/37 ====
---- Publisher Session 2033564099 ----
| publisher position: 19584
| publisher limit: 26240
| sender position: 26240
| sender limit: 133440
---- Subscriber ----
| receiver position: 26240
| receiver HWM: 26240
| position (1): 3520
| position (2): 2432
| position (3): 2368
-----------------------------------------
==== aeron:udp?endpoint=localhost:54587/37 ====
---- Publisher Session 2033564101 ----
| publisher position: 320
| publisher limit: 576
| sender position: 576
| sender limit: 131264
---- Subscriber ----
| receiver position: 576
| receiver HWM: 576
| position (6): 192
-----------------------------------------

As an Application

Collector

To run Aether as a command-line application, runtime configuration can be used:

aether-collector.properties

# Describes the locations of MediaDrivers that should be monitored
aether.monitoringLocations=client:/path/to/client/media-driver;server:/path/to/server/media-driver
# Tells Aether to publish snapshot over an Aeron Publication
aether.transport=AERON
# Tells Aether to monitor locations and publish
aether.mode=PUBLISHER
# Describes the location where Aether should launch its own MediaDriver for publishing
aeron.dir=/path/to/aether-publisher-media-driver
# Describe the endpoint to publish data to
aether.transport.channel=aeron:udp?endpoint=monitoring-host:18996

Then run the collector:

java -cp /path/to/aeron-driver.jar:/path/to/aether.jar \
com.aitusoftware.aether.Aether /path/to/aether-collector.properties

Aggregator

aether-aggregator.properties

# Tells Aether to receive snapshot over an Aeron Publication
aether.transport=AERON
# Tells Aether to subscribe to events
aether.mode=SUBSCRIBER
# Describes the location where Aether should launch its own MediaDriver for subscribing
aeron.dir=/path/to/aether-subscriber-media-driver
# Describe the endpoint to receive data on
aether.transport.channel=aeron:udp?endpoint=monitoring-host:18996

Then run the aggregator:

java -cp /path/to/aeron-driver.jar:/path/to/aether.jar \
com.aitusoftware.aether.Aether /path/to/aether-aggregator.properties

Visualising snapshot data

Aether-Net provides a simple UI to display the counter snapshots.