refactor: Update OpenTelemetry to version 1.11

This change updates the OpenDC codebase to use OpenTelemetry v1.11,
which stabilizes the metrics API. This stabilization brings quite a few
breaking changes, so significant changes are necessary inside the OpenDC
codebase.

3 files changed, 67 insertions, 65 deletions

diff --git a/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/SimHost.kt b/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/SimHost.kt
index 908a58e9..95921e8b 100644
--- a/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/SimHost.kt
+++ b/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/SimHost.kt
@@ -150,15 +150,15 @@ public class SimHost(
         meter.gaugeBuilder("system.cpu.demand")
             .setDescription("Amount of CPU resources the guests would use if there were no CPU contention or CPU limits")
             .setUnit("MHz")
-            .buildWithCallback { result -> result.observe(hypervisor.cpuDemand) }
+            .buildWithCallback { result -> result.record(hypervisor.cpuDemand) }
         meter.gaugeBuilder("system.cpu.usage")
             .setDescription("Amount of CPU resources used by the host")
             .setUnit("MHz")
-            .buildWithCallback { result -> result.observe(hypervisor.cpuUsage) }
+            .buildWithCallback { result -> result.record(hypervisor.cpuUsage) }
         meter.gaugeBuilder("system.cpu.utilization")
             .setDescription("Utilization of the CPU resources of the host")
             .setUnit("%")
-            .buildWithCallback { result -> result.observe(hypervisor.cpuUsage / _cpuLimit) }
+            .buildWithCallback { result -> result.record(hypervisor.cpuUsage / _cpuLimit) }
         meter.counterBuilder("system.cpu.time")
             .setDescription("Amount of CPU time spent by the host")
             .setUnit("s")
@@ -166,12 +166,12 @@ public class SimHost(
         meter.gaugeBuilder("system.power.usage")
             .setDescription("Power usage of the host ")
             .setUnit("W")
-            .buildWithCallback { result -> result.observe(machine.powerUsage) }
+            .buildWithCallback { result -> result.record(machine.powerUsage) }
         meter.counterBuilder("system.power.total")
             .setDescription("Amount of energy used by the CPU")
             .setUnit("J")
             .ofDoubles()
-            .buildWithCallback { result -> result.observe(machine.energyUsage) }
+            .buildWithCallback { result -> result.record(machine.energyUsage) }
         meter.counterBuilder("system.time")
             .setDescription("The uptime of the host")
             .setUnit("s")
@@ -382,10 +382,10 @@ public class SimHost(
             }
         }
 
-        result.observe(terminated, terminatedState)
-        result.observe(running, runningState)
-        result.observe(error, errorState)
-        result.observe(invalid, invalidState)
+        result.record(terminated, terminatedState)
+        result.record(running, runningState)
+        result.record(error, errorState)
+        result.record(invalid, invalidState)
     }
 
     private val _cpuLimit = machine.model.cpus.sumOf { it.frequency }
@@ -394,7 +394,7 @@ public class SimHost(
      * Helper function to collect the CPU limits of a machine.
      */
     private fun collectCpuLimit(result: ObservableDoubleMeasurement) {
-        result.observe(_cpuLimit)
+        result.record(_cpuLimit)
 
         val guests = _guests
         for (i in guests.indices) {
@@ -413,10 +413,10 @@ public class SimHost(
     private fun collectCpuTime(result: ObservableLongMeasurement) {
         val counters = hypervisor.counters
 
-        result.observe(counters.cpuActiveTime / 1000L, _activeState)
-        result.observe(counters.cpuIdleTime / 1000L, _idleState)
-        result.observe(counters.cpuStealTime / 1000L, _stealState)
-        result.observe(counters.cpuLostTime / 1000L, _lostState)
+        result.record(counters.cpuActiveTime / 1000L, _activeState)
+        result.record(counters.cpuIdleTime / 1000L, _idleState)
+        result.record(counters.cpuStealTime / 1000L, _stealState)
+        result.record(counters.cpuLostTime / 1000L, _lostState)
 
         val guests = _guests
         for (i in guests.indices) {
@@ -458,8 +458,8 @@ public class SimHost(
     private fun collectUptime(result: ObservableLongMeasurement) {
         updateUptime()
 
-        result.observe(_uptime, _upState)
-        result.observe(_downtime, _downState)
+        result.record(_uptime, _upState)
+        result.record(_downtime, _downState)
 
         val guests = _guests
         for (i in guests.indices) {
@@ -474,7 +474,7 @@ public class SimHost(
      */
     private fun collectBootTime(result: ObservableLongMeasurement) {
         if (_bootTime != Long.MIN_VALUE) {
-            result.observe(_bootTime)
+            result.record(_bootTime)
         }
 
         val guests = _guests
diff --git a/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/internal/Guest.kt b/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/internal/Guest.kt
index 9f3122db..f49c2824 100644
--- a/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/internal/Guest.kt
+++ b/opendc-compute/opendc-compute-simulator/src/main/kotlin/org/opendc/compute/simulator/internal/Guest.kt
@@ -239,8 +239,8 @@ internal class Guest(
      * Helper function to track the uptime of the guest.
      */
     fun collectUptime(result: ObservableLongMeasurement) {
-        result.observe(_uptime, _upState)
-        result.observe(_downtime, _downState)
+        result.record(_uptime, _upState)
+        result.record(_downtime, _downState)
     }
 
     private var _bootTime = Long.MIN_VALUE
@@ -250,7 +250,7 @@ internal class Guest(
      */
     fun collectBootTime(result: ObservableLongMeasurement) {
         if (_bootTime != Long.MIN_VALUE) {
-            result.observe(_bootTime, attributes)
+            result.record(_bootTime, attributes)
         }
     }
 
@@ -273,10 +273,10 @@ internal class Guest(
     fun collectCpuTime(result: ObservableLongMeasurement) {
         val counters = machine.counters
 
-        result.observe(counters.cpuActiveTime / 1000, _activeState)
-        result.observe(counters.cpuIdleTime / 1000, _idleState)
-        result.observe(counters.cpuStealTime / 1000, _stealState)
-        result.observe(counters.cpuLostTime / 1000, _lostState)
+        result.record(counters.cpuActiveTime / 1000, _activeState)
+        result.record(counters.cpuIdleTime / 1000, _idleState)
+        result.record(counters.cpuStealTime / 1000, _stealState)
+        result.record(counters.cpuLostTime / 1000, _lostState)
     }
 
     private val _cpuLimit = machine.model.cpus.sumOf { it.frequency }
@@ -285,7 +285,7 @@ internal class Guest(
      * Helper function to collect the CPU limits of a machine.
      */
     fun collectCpuLimit(result: ObservableDoubleMeasurement) {
-        result.observe(_cpuLimit, attributes)
+        result.record(_cpuLimit, attributes)
     }
 
     /**
diff --git a/opendc-compute/opendc-compute-simulator/src/test/kotlin/org/opendc/compute/simulator/SimHostTest.kt b/opendc-compute/opendc-compute-simulator/src/test/kotlin/org/opendc/compute/simulator/SimHostTest.kt
index 799a8cf0..dd13b60c 100644
--- a/opendc-compute/opendc-compute-simulator/src/test/kotlin/org/opendc/compute/simulator/SimHostTest.kt
+++ b/opendc-compute/opendc-compute-simulator/src/test/kotlin/org/opendc/compute/simulator/SimHostTest.kt
@@ -22,9 +22,7 @@
 
 package org.opendc.compute.simulator
 
-import io.opentelemetry.api.metrics.MeterProvider
 import io.opentelemetry.sdk.metrics.SdkMeterProvider
-import io.opentelemetry.sdk.metrics.export.MetricProducer
 import io.opentelemetry.sdk.resources.Resource
 import kotlinx.coroutines.*
 import org.junit.jupiter.api.Assertions.assertEquals
@@ -83,10 +81,26 @@ internal class SimHostTest {
         val hostResource = Resource.builder()
             .put(HOST_ID, hostId.toString())
             .build()
-        val meterProvider: MeterProvider = SdkMeterProvider
+
+        // Setup metric reader
+        val duration = 5 * 60L
+        val reader = CoroutineMetricReader(
+            this,
+            object : ComputeMetricExporter() {
+                override fun record(reader: HostTableReader) {
+                    activeTime += reader.cpuActiveTime
+                    idleTime += reader.cpuIdleTime
+                    stealTime += reader.cpuStealTime
+                }
+            },
+            exportInterval = Duration.ofSeconds(duration)
+        )
+
+        val meterProvider = SdkMeterProvider
             .builder()
             .setResource(hostResource)
             .setClock(clock.toOtelClock())
+            .registerMetricReader(reader)
             .build()
 
         val engine = FlowEngine(coroutineContext, clock)
@@ -100,7 +114,6 @@ internal class SimHostTest {
             meterProvider,
             SimFairShareHypervisorProvider()
         )
-        val duration = 5 * 60L
         val vmImageA = MockImage(
             UUID.randomUUID(),
             "<unnamed>",
@@ -136,19 +149,6 @@ internal class SimHostTest {
 
         val flavor = MockFlavor(2, 0)
 
-        // Setup metric reader
-        val reader = CoroutineMetricReader(
-            this, listOf(meterProvider as MetricProducer),
-            object : ComputeMetricExporter() {
-                override fun record(reader: HostTableReader) {
-                    activeTime += reader.cpuActiveTime
-                    idleTime += reader.cpuIdleTime
-                    stealTime += reader.cpuStealTime
-                }
-            },
-            exportInterval = Duration.ofSeconds(duration)
-        )
-
         coroutineScope {
             launch { virtDriver.spawn(MockServer(UUID.randomUUID(), "a", flavor, vmImageA)) }
             launch { virtDriver.spawn(MockServer(UUID.randomUUID(), "b", flavor, vmImageB)) }
@@ -169,7 +169,7 @@ internal class SimHostTest {
         // Ensure last cycle is collected
         delay(1000L * duration)
         virtDriver.close()
-        reader.close()
+        meterProvider.close()
 
         assertAll(
             { assertEquals(658, activeTime, "Active time does not match") },
@@ -195,10 +195,32 @@ internal class SimHostTest {
         val hostResource = Resource.builder()
             .put(HOST_ID, hostId.toString())
             .build()
-        val meterProvider: MeterProvider = SdkMeterProvider
+
+        // Setup metric reader
+        val duration = 5 * 60L
+        val reader = CoroutineMetricReader(
+            this,
+            object : ComputeMetricExporter() {
+                override fun record(reader: HostTableReader) {
+                    activeTime += reader.cpuActiveTime
+                    idleTime += reader.cpuIdleTime
+                    uptime += reader.uptime
+                    downtime += reader.downtime
+                }
+
+                override fun record(reader: ServerTableReader) {
+                    guestUptime += reader.uptime
+                    guestDowntime += reader.downtime
+                }
+            },
+            exportInterval = Duration.ofSeconds(duration)
+        )
+
+        val meterProvider = SdkMeterProvider
             .builder()
             .setResource(hostResource)
             .setClock(clock.toOtelClock())
+            .registerMetricReader(reader)
             .build()
 
         val engine = FlowEngine(coroutineContext, clock)
@@ -212,7 +234,6 @@ internal class SimHostTest {
             meterProvider,
             SimFairShareHypervisorProvider()
         )
-        val duration = 5 * 60L
         val image = MockImage(
             UUID.randomUUID(),
             "<unnamed>",
@@ -232,25 +253,6 @@ internal class SimHostTest {
         val flavor = MockFlavor(2, 0)
         val server = MockServer(UUID.randomUUID(), "a", flavor, image)
 
-        // Setup metric reader
-        val reader = CoroutineMetricReader(
-            this, listOf(meterProvider as MetricProducer),
-            object : ComputeMetricExporter() {
-                override fun record(reader: HostTableReader) {
-                    activeTime += reader.cpuActiveTime
-                    idleTime += reader.cpuIdleTime
-                    uptime += reader.uptime
-                    downtime += reader.downtime
-                }
-
-                override fun record(reader: ServerTableReader) {
-                    guestUptime += reader.uptime
-                    guestDowntime += reader.downtime
-                }
-            },
-            exportInterval = Duration.ofSeconds(duration)
-        )
-
         coroutineScope {
             host.spawn(server)
             delay(5000L)
@@ -273,7 +275,7 @@ internal class SimHostTest {
         // Ensure last cycle is collected
         delay(1000L * duration)
 
-        reader.close()
+        meterProvider.close()
 
         assertAll(
             { assertEquals(1175, idleTime, "Idle time does not match") },