Create Client side metrics for redis (#10271)

* Create Client side metrics for redis

* Create pom.xml for RedisTelemetryApp

* Update license

* Update pom.xml

* Update RedisTelemetryApp.java

* Update pom.xml

* Update pom.xml

* Update pom.xml

* fis:add tests

* fis:style:make the code style compliant to pass lints

* fis:style:add header to package-info.java

* fis:style:fix style in package-info.java

Author: fosky94

memorystore/redis/client_side_metrics/pom.xml

@@ -0,0 +1,100 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!--
+    Copyright 2026 Google LLC
+
+    Licensed under the Apache License, Version 2.0 (the "License");
+    you may not use this file except in compliance with the License.
+    You may obtain a copy of the License at
+
+        http://www.apache.org/licenses/LICENSE-2.0
+
+    Unless required by applicable law or agreed to in writing, software
+    distributed under the License is distributed on an "AS IS" BASIS,
+    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+    See the License for the specific language governing permissions and
+    limitations under the License.
+-->
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+
+    <groupId>com.example.memorystore</groupId>
+    <artifactId>redis-client-side-metrics</artifactId>
+    <version>1.0-SNAPSHOT</version>
+
+    <properties>
+        <maven.compiler.source>1.8</maven.compiler.source>
+        <maven.compiler.target>1.8</maven.compiler.target>
+        <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    </properties>
+
+    <!-- [START memorystore_redis_client_side_metrics_dependencies] -->
+    <dependencies>
+        <dependency>
+            <groupId>redis.clients</groupId>
+            <artifactId>jedis</artifactId>
+            <version>5.1.0</version>
+        </dependency>
+        <dependency>
+            <groupId>io.opentelemetry</groupId>
+            <artifactId>opentelemetry-api</artifactId>
+            <version>1.36.0</version>
+        </dependency>
+        <dependency>
+            <groupId>io.opentelemetry</groupId>
+            <artifactId>opentelemetry-sdk</artifactId>
+            <version>1.36.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.cloud.opentelemetry</groupId>
+            <artifactId>exporter-trace</artifactId>
+            <version>0.28.0</version>
+        </dependency>
+        <dependency>
+            <groupId>com.google.cloud.opentelemetry</groupId>
+            <artifactId>exporter-metrics</artifactId>
+            <version>0.28.0</version>
+        </dependency>
+
+        <!-- Testing Dependencies -->
+        <dependency>
+            <groupId>junit</groupId>
+            <artifactId>junit</artifactId>
+            <version>4.13.2</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.mockito</groupId>
+            <artifactId>mockito-core</artifactId>
+            <version>4.11.0</version>
+            <scope>test</scope>
+        </dependency>
+        <dependency>
+            <groupId>org.slf4j</groupId>
+            <artifactId>slf4j-simple</artifactId>
+            <version>1.7.36</version>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+    <!-- [END memorystore_redis_client_side_metrics_dependencies] -->
+
+    <build>
+        <plugins>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-compiler-plugin</artifactId>
+                <version>3.12.1</version>
+                <configuration>
+                    <source>1.8</source>
+                    <target>1.8</target>
+                </configuration>
+            </plugin>
+            <plugin>
+                <groupId>org.apache.maven.plugins</groupId>
+                <artifactId>maven-surefire-plugin</artifactId>
+                <version>3.2.5</version>
+            </plugin>
+        </plugins>
+    </build>
+</project>

memorystore/redis/client_side_metrics/src/main/java/com/example/memorystore/redis/RedisTelemetryApp.java

@@ -0,0 +1,290 @@
+/*
+ * Copyright 2026 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.example.memorystore.redis;
+
+// [START memorystore_redis_client_side_metrics]
+import com.google.cloud.opentelemetry.metric.GoogleCloudMetricExporter;
+import com.google.cloud.opentelemetry.trace.TraceExporter;
+import io.opentelemetry.api.OpenTelemetry;
+import io.opentelemetry.api.common.AttributeKey;
+import io.opentelemetry.api.common.Attributes;
+import io.opentelemetry.api.metrics.DoubleHistogram;
+import io.opentelemetry.api.metrics.LongCounter;
+import io.opentelemetry.api.metrics.Meter;
+import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.Tracer;
+import io.opentelemetry.sdk.OpenTelemetrySdk;
+import io.opentelemetry.sdk.metrics.export.MetricExporter;
+import io.opentelemetry.sdk.metrics.SdkMeterProvider;
+import io.opentelemetry.sdk.metrics.export.PeriodicMetricReader;
+import io.opentelemetry.sdk.trace.SdkTracerProvider;
+import io.opentelemetry.sdk.trace.export.BatchSpanProcessor;
+import io.opentelemetry.sdk.trace.export.SpanExporter;
+import redis.clients.jedis.Jedis;
+import redis.clients.jedis.JedisPool;
+import redis.clients.jedis.JedisPoolConfig;
+import redis.clients.jedis.exceptions.JedisConnectionException;
+
+import java.time.Duration;
+import java.util.function.Function;
+
+/**
+ * Sample application demonstrating client-side metrics and tracing for
+ * Google Cloud Memorystore for Redis.
+ */
+public final class RedisTelemetryApp {
+    /** Attribute key for Redis operation names. */
+    private static final AttributeKey<String> ATTR_OPERATION =
+            AttributeKey.stringKey("operation");
+
+    /** Maximum number of Redis reconnection attempts. */
+    private static final int MAX_RETRIES = 3;
+
+    /** Maximum total connections for the Jedis pool. */
+    private static final int POOL_MAX_TOTAL = 20;
+
+    /** Interval in seconds for exporting metrics to Google Cloud. */
+    private static final long METRIC_INTERVAL_SECONDS = 10L;
+
+    /** Base multiplier for exponential backoff sleep (in milliseconds). */
+    private static final long RETRY_BACKOFF_BASE_MS = 100L;
+
+    /** Conversion factor from Nanoseconds to Milliseconds. */
+    private static final double NANO_TO_MS = 1_000_000.0;
+
+    /** Default Redis port. */
+    private static final int DEFAULT_REDIS_PORT = 6379;
+
+    /** OpenTelemetry Tracer instance for recording trace spans. */
+    private static Tracer tracer;
+
+    /** OpenTelemetry Histogram for Redis round-trip time. */
+    private static DoubleHistogram rttHist;
+
+    /** OpenTelemetry Histogram for pool blocking latency. */
+    private static DoubleHistogram clientBlockHist;
+
+    /** OpenTelemetry Histogram for application logic blocking latency. */
+    private static DoubleHistogram appBlockHist;
+
+    /** OpenTelemetry Counter for Redis reconnection retry events. */
+    private static LongCounter retryCounter;
+
+    /** OpenTelemetry Counter for Redis connectivity errors. */
+    private static LongCounter connErrorCounter;
+
+    /** Shared Jedis connection pool. */
+    private static JedisPool jedisPool;
+
+    /**
+     * Private constructor to prevent instantiation of this utility class.
+     */
+    private RedisTelemetryApp() {
+    }
+
+    /**
+     * Main entry point for running the sample application.
+     *
+     * @param args Command line arguments (not used).
+     */
+    public static void main(final String[] args) {
+        setupTelemetry();
+
+        final String host = System.getenv()
+                .getOrDefault("REDISHOST", "localhost");
+        final int port = Integer.parseInt(System.getenv()
+                .getOrDefault("REDISPORT",
+                        String.valueOf(DEFAULT_REDIS_PORT)));
+
+        final JedisPoolConfig poolConfig = new JedisPoolConfig();
+        poolConfig.setMaxTotal(POOL_MAX_TOTAL);
+        poolConfig.setBlockWhenExhausted(true);
+        jedisPool = new JedisPool(poolConfig, host, port);
+
+        try {
+            run();
+        } finally {
+            if (jedisPool != null) {
+                jedisPool.close();
+            }
+        }
+    }
+
+    /**
+     * Executes the core business logic of reading and writing to Redis.
+     *
+     * @return The string retrieved from the Redis 'get' operation.
+     */
+    static String run() {
+        final Span span = tracer.spanBuilder("process_user_span")
+                .startSpan();
+        try {
+            smartRedisCall("set_user", jedis ->
+                    jedis.set("user:123", "active"));
+
+            final String result = smartRedisCall("get_user", jedis ->
+                    jedis.get("user:123"));
+            System.out.println("Retrieved: " + result);
+            return result;
+        } catch (Exception e) {
+            span.recordException(e);
+            throw e;
+        } finally {
+            span.end();
+        }
+    }
+
+    /**
+     * Injects mocked or no-op telemetry and pool instances for unit testing.
+     *
+     * @param pool                The mocked or test JedisPool instance.
+     * @param testOpenTelemetry The OpenTelemetry instance to use for testing.
+     */
+    static void initForTest(
+            final JedisPool pool,
+            final OpenTelemetry testOpenTelemetry) {
+        jedisPool = pool;
+        tracer = testOpenTelemetry.getTracer("jedis.client");
+        final Meter meter = testOpenTelemetry.getMeter("jedis.metrics");
+
+        rttHist = meter.histogramBuilder("redis_client_rtt")
+                .setUnit("ms").build();
+        clientBlockHist = meter
+                .histogramBuilder("redis_client_blocking_latency")
+                .setUnit("ms").build();
+        appBlockHist = meter
+                .histogramBuilder("redis_application_blocking_latency")
+                .setUnit("ms").build();
+        retryCounter = meter.counterBuilder("redis_retry_count").build();
+        connErrorCounter = meter
+                .counterBuilder("redis_connectivity_error_count")
+                .build();
+
+        retryCounter.add(0, Attributes.of(ATTR_OPERATION, "startup"));
+        connErrorCounter.add(0, Attributes.of(ATTR_OPERATION, "startup"));
+    }
+
+    /**
+     * Configures the production OpenTelemetry SDK to export Traces and Metrics
+     * to Google Cloud Operations.
+     */
+    private static void setupTelemetry() {
+        final SpanExporter traceExporter =
+                TraceExporter.createWithDefaultConfiguration();
+        final SdkTracerProvider tracerProvider =
+                SdkTracerProvider.builder()
+                        .addSpanProcessor(
+                                BatchSpanProcessor.builder(traceExporter)
+                                        .build())
+                        .build();
+
+        final MetricExporter metricExporter =
+                GoogleCloudMetricExporter.createWithDefaultConfiguration();
+        final SdkMeterProvider meterProvider =
+                SdkMeterProvider.builder()
+                        .registerMetricReader(
+                                PeriodicMetricReader.builder(metricExporter)
+                                        .setInterval(Duration.ofSeconds(
+                                                METRIC_INTERVAL_SECONDS))
+                                        .build())
+                        .build();
+
+        final OpenTelemetry openTelemetry = OpenTelemetrySdk.builder()
+                .setTracerProvider(tracerProvider)
+                .setMeterProvider(meterProvider)
+                .buildAndRegisterGlobal();
+
+        tracer = openTelemetry.getTracer("jedis.client");
+        final Meter meter = openTelemetry.getMeter("jedis.metrics");
+
+        rttHist = meter.histogramBuilder("redis_client_rtt")
+                .setUnit("ms").build();
+        clientBlockHist = meter
+                .histogramBuilder("redis_client_blocking_latency")
+                .setUnit("ms").build();
+        appBlockHist = meter
+                .histogramBuilder("redis_application_blocking_latency")
+                .setUnit("ms").build();
+        retryCounter = meter.counterBuilder("redis_retry_count").build();
+        connErrorCounter = meter
+                .counterBuilder("redis_connectivity_error_count")
+                .build();
+
+        retryCounter.add(0, Attributes.of(ATTR_OPERATION, "startup"));
+        connErrorCounter.add(0, Attributes.of(ATTR_OPERATION, "startup"));
+    }
+
+    /**
+     * Wraps a Redis operation with latency metrics, reconnection retry logic,
+     * and trace spans.
+     *
+     * @param <T>           The return type of the Redis operation.
+     * @param operationName The name of the operation for metric attributes.
+     * @param operation     The Redis command lambda to execute safely.
+     * @return The return value from the Redis command.
+     */
+    private static <T> T smartRedisCall(
+            final String operationName,
+            final Function<Jedis, T> operation) {
+        int attempt = 0;
+        final Attributes attrs = Attributes.of(ATTR_OPERATION,
+                operationName);
+
+        final Span span = tracer.spanBuilder(operationName).startSpan();
+
+        try {
+            while (attempt < MAX_RETRIES) {
+                final long poolStart = System.nanoTime();
+                try (Jedis jedis = jedisPool.getResource()) {
+                    clientBlockHist.record((System.nanoTime() - poolStart)
+                            / NANO_TO_MS, attrs);
+
+                    final long reqStart = System.nanoTime();
+                    final T response = operation.apply(jedis);
+                    rttHist.record((System.nanoTime() - reqStart)
+                            / NANO_TO_MS, attrs);
+
+                    final long appStart = System.nanoTime();
+                    @SuppressWarnings("unused")
+                    final String dummy = String.valueOf(response);
+                    appBlockHist.record((System.nanoTime() - appStart)
+                            / NANO_TO_MS, attrs);
+
+                    return response;
+                } catch (JedisConnectionException e) {
+                    attempt++;
+                    connErrorCounter.add(1, attrs);
+                    retryCounter.add(1, attrs);
+                    span.recordException(e);
+                    if (attempt >= MAX_RETRIES) {
+                        throw e;
+                    }
+                    try {
+                        Thread.sleep((long) (Math.pow(2, attempt)
+                                * RETRY_BACKOFF_BASE_MS));
+                    } catch (InterruptedException ie) {
+                        Thread.currentThread().interrupt();
+                    }
+                }
+            }
+            return null;
+        } finally {
+            span.end();
+        }
+    }
+}
+// [END memorystore_redis_client_side_metrics]