Add configurable metric_timestamp_source, metric_timestamp_granularity, stable host ID, and NodeOperationDetail dedup for APM service map processor (opensearch-project#6672)

Signed-off-by: vamsimanohar <vamsimanohar@users.noreply.github.com>

Signed-off-by: Vamsi Manohar <reddyvam@amazon.com>

Author: vamsimanohar

data-prepper-api/src/main/java/org/opensearch/dataprepper/model/host/HostContext.java

@@ -0,0 +1,45 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.dataprepper.model.host;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.net.InetAddress;
+
+/**
+ * Provides the hostname of the current Data Prepper instance.
+ * This is intended as a shared utility so that hostname resolution
+ * is consistent across all components (processors, source coordinators, etc.).
+ */
+public class HostContext {
+
+    private static final Logger LOG = LoggerFactory.getLogger(HostContext.class);
+    private static final String UNKNOWN_HOST = "unknown";
+    private static final String HOSTNAME = resolveHostname();
+
+    static String resolveHostname() {
+        try {
+            return InetAddress.getLocalHost().getHostName();
+        } catch (final Exception e) {
+            LOG.warn("Failed to resolve hostname, using '{}': {}", UNKNOWN_HOST, e.getMessage());
+            return UNKNOWN_HOST;
+        }
+    }
+
+    /**
+     * Returns the hostname of the current Data Prepper host.
+     *
+     * @return the hostname
+     */
+    public static String getHostname() {
+        return HOSTNAME;
+    }
+}

data-prepper-api/src/test/java/org/opensearch/dataprepper/model/host/HostContextTest.java

@@ -0,0 +1,68 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ */
+
+package org.opensearch.dataprepper.model.host;
+
+import org.junit.jupiter.api.Test;
+import org.mockito.MockedStatic;
+
+import java.net.InetAddress;
+import java.net.UnknownHostException;
+
+import static org.hamcrest.CoreMatchers.equalTo;
+import static org.hamcrest.CoreMatchers.notNullValue;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.Matchers.not;
+import static org.hamcrest.Matchers.emptyString;
+import static org.mockito.Mockito.mockStatic;
+
+class HostContextTest {
+
+    @Test
+    void getHostname_returns_non_null_non_empty_value() {
+        final String hostname = HostContext.getHostname();
+        assertThat(hostname, notNullValue());
+        assertThat(hostname, not(emptyString()));
+    }
+
+    @Test
+    void getHostname_returns_consistent_value() {
+        final String first = HostContext.getHostname();
+        final String second = HostContext.getHostname();
+        assertThat(first, equalTo(second));
+    }
+
+    @Test
+    void getHostname_matches_InetAddress_hostname() throws UnknownHostException {
+        final String expected = InetAddress.getLocalHost().getHostName();
+        assertThat(HostContext.getHostname(), equalTo(expected));
+    }
+
+    @Test
+    void resolveHostname_returns_valid_hostname() throws UnknownHostException {
+        final String hostname = HostContext.resolveHostname();
+        assertThat(hostname, equalTo(InetAddress.getLocalHost().getHostName()));
+    }
+
+    @Test
+    void resolveHostname_returns_unknown_when_hostname_cannot_be_resolved() {
+        try (final MockedStatic<InetAddress> inetAddressMock = mockStatic(InetAddress.class)) {
+            inetAddressMock.when(InetAddress::getLocalHost)
+                    .thenThrow(new UnknownHostException("test exception"));
+
+            assertThat(HostContext.resolveHostname(), equalTo("unknown"));
+        }
+    }
+
+    @Test
+    void constructor_can_be_created() {
+        final HostContext hostContext = new HostContext();
+        assertThat(hostContext, notNullValue());
+    }
+}

data-prepper-plugins/otel-apm-service-map-processor/README.md

@@ -34,6 +34,8 @@ processor:
 | `window_duration` | Duration | `60s` | Fixed time window in seconds for evaluating APM service map relationships |
 | `db_path` | String | `"data/otel-apm-service-map/"` | Directory path for database files storing transient processing data |
 | `group_by_attributes` | List\<String\> | `[]` | OpenTelemetry resource attributes to include in service grouping |
+| `metric_timestamp_source` | String | `"arrival_time"` | Timestamp source for emitted metrics. `"arrival_time"` uses processing time at window evaluation (avoids late-span data loss in Prometheus/AMP). `"span_end_time"` uses the span's `endTime` field. |
+| `metric_timestamp_granularity` | String | `"seconds"` | Truncation granularity for metric and service map timestamps. `"seconds"` truncates to second boundaries (1s collision window). `"minutes"` truncates to minute boundaries (60s collision window). |
 
 ### Advanced Configuration
 
@@ -42,13 +44,37 @@ processor:
   - otel_apm_service_map:
       window_duration: 120s  # 2-minute windows for high-latency services
       db_path: "/tmp/apm-service-map/"
+      metric_timestamp_source: arrival_time
+      metric_timestamp_granularity: seconds
       group_by_attributes:
         - "service.version"
         - "deployment.environment"
         - "service.namespace"
         - "k8s.cluster.name"
 ```
 
+### Metric Timestamp Source
+
+The `metric_timestamp_source` option controls what timestamp is used for emitted metrics.
+
+| Value | Timestamp used | Late-span safe | Description |
+|---|---|---|---|
+| `arrival_time` (default) | `clock.instant()` at window evaluation | Yes | All spans in a window share the same processing timestamp. Matches the [OTel Collector spanmetrics connector](https://github.com/open-telemetry/opentelemetry-collector-contrib/tree/main/connector/spanmetricsconnector) approach. |
+| `span_end_time` | Span's `endTime` field | No | Each span's end time is used. Late-arriving spans may produce metrics with timestamps that collide with previously written data points, causing silent data loss in Prometheus/AMP. |
+
+**Recommendation:** Use the default `arrival_time` unless you have a specific requirement for span-aligned timestamps and accept the risk of late-span data loss.
+
+### Metric Timestamp Granularity
+
+The `metric_timestamp_granularity` option controls the truncation granularity for all emitted timestamps (metrics and service map events).
+
+| Value | Collision window (`span_end_time` mode) | Data points per window | Description |
+|---|---|---|---|
+| `seconds` (default) | 1 second | More (one per unique second) | Truncates to second boundaries. Minimizes collision risk in `span_end_time` mode. |
+| `minutes` | 60 seconds | Fewer (one per unique minute) | Truncates to minute boundaries. Higher collision risk but fewer data points. |
+
+In `arrival_time` mode, granularity has minimal impact since all spans in a window share the same `clock.instant()` — each window always produces one data point per label combination regardless of truncation.
+
 ## Pipeline Examples
 
 ### Basic Pipeline

data-prepper-plugins/otel-apm-service-map-processor/src/main/java/org/opensearch/dataprepper/plugins/processor/otel_apm_service_map/MetricTimestampGranularity.java

@@ -0,0 +1,50 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ */
+
+package org.opensearch.dataprepper.plugins.processor.otel_apm_service_map;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+
+import java.time.temporal.ChronoUnit;
+import java.util.Arrays;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public enum MetricTimestampGranularity {
+    SECONDS("seconds", ChronoUnit.SECONDS),
+    MINUTES("minutes", ChronoUnit.MINUTES);
+
+    private static final Map<String, MetricTimestampGranularity> OPTIONS_MAP = Arrays.stream(MetricTimestampGranularity.values())
+            .collect(Collectors.toMap(
+                    value -> value.option,
+                    value -> value
+            ));
+
+    private final String option;
+    private final ChronoUnit chronoUnit;
+
+    MetricTimestampGranularity(final String option, final ChronoUnit chronoUnit) {
+        this.option = option;
+        this.chronoUnit = chronoUnit;
+    }
+
+    public String getOption() {
+        return option;
+    }
+
+    public ChronoUnit getChronoUnit() {
+        return chronoUnit;
+    }
+
+    @JsonCreator
+    public static MetricTimestampGranularity fromOptionValue(final String option) {
+        return OPTIONS_MAP.get(option);
+    }
+}

data-prepper-plugins/otel-apm-service-map-processor/src/main/java/org/opensearch/dataprepper/plugins/processor/otel_apm_service_map/MetricTimestampSource.java

@@ -0,0 +1,43 @@
+/*
+ * Copyright OpenSearch Contributors
+ * SPDX-License-Identifier: Apache-2.0
+ *
+ * The OpenSearch Contributors require contributions made to
+ * this file be licensed under the Apache-2.0 license or a
+ * compatible open source license.
+ *
+ */
+
+package org.opensearch.dataprepper.plugins.processor.otel_apm_service_map;
+
+import com.fasterxml.jackson.annotation.JsonCreator;
+
+import java.util.Arrays;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+public enum MetricTimestampSource {
+    ARRIVAL_TIME("arrival_time"),
+    SPAN_END_TIME("span_end_time");
+
+    private static final Map<String, MetricTimestampSource> OPTIONS_MAP = Arrays.stream(MetricTimestampSource.values())
+            .collect(Collectors.toMap(
+                    value -> value.option,
+                    value -> value
+            ));
+
+    private final String option;
+
+    MetricTimestampSource(final String option) {
+        this.option = option;
+    }
+
+    public String getOption() {
+        return option;
+    }
+
+    @JsonCreator
+    public static MetricTimestampSource fromOptionValue(final String option) {
+        return OPTIONS_MAP.get(option);
+    }
+}