[cosmos] Fix ClientTelemetry static-init NPE when IMDS access is disabled

sdk/cosmos/azure-cosmos-tests/src/test/java/com/azure/cosmos/implementation/ClientConfigDiagnosticsTest.java

@@ -11,6 +11,7 @@
 import com.azure.cosmos.CosmosRegionSwitchHint;
 import com.azure.cosmos.SessionRetryOptions;
 import com.azure.cosmos.SessionRetryOptionsBuilder;
+import com.azure.cosmos.implementation.clienttelemetry.ClientTelemetry;
 import com.azure.cosmos.implementation.perPartitionCircuitBreaker.PartitionLevelCircuitBreakerConfig;
 import com.azure.cosmos.implementation.directconnectivity.RntbdTransportClient;
 import com.azure.cosmos.implementation.guava25.collect.ImmutableList;
@@ -40,6 +41,8 @@
 import static org.assertj.core.api.Assertions.assertThat;
 
 public class ClientConfigDiagnosticsTest {
+    private static final String vmInstanceMachineId = ClientTelemetry.getMachineId(null);
+
     private final ObjectMapper objectMapper = new ObjectMapper();
     private static final ImplementationBridgeHelpers.CosmosContainerIdentityHelper.CosmosContainerIdentityAccessor containerIdentityAccessor = ImplementationBridgeHelpers
         .CosmosContainerIdentityHelper
@@ -165,7 +168,7 @@ public void bareMinimum() throws Exception {
         ObjectNode objectNode = (ObjectNode) objectMapper.readTree(jsonWriter.toString());
 
         assertThat(objectNode.get("id").asInt()).isEqualTo(1);
-        assertThat(objectNode.get("machineId").asText()).isEqualTo(machineId);
+        assertThat(objectNode.get("machineId").asText()).isEqualTo(Strings.isNullOrEmpty(vmInstanceMachineId) ? machineId : vmInstanceMachineId);
         assertThat(objectNode.get("numberOfClients").asInt()).isEqualTo(2);
         assertThat(objectNode.get("consistencyCfg").asText()).isEqualTo("(consistency: null, readConsistencyStrategy: null,  mm: false, prgns: [null])");
         assertThat(objectNode.get("connCfg").get("rntbd").asText()).isEqualTo("null");
@@ -198,7 +201,7 @@ public void rntbd() throws Exception {
         ObjectNode objectNode = (ObjectNode) objectMapper.readTree(jsonWriter.toString());
 
         assertThat(objectNode.get("id").asInt()).isEqualTo(1);
-        assertThat(objectNode.get("machineId").asText()).isEqualTo(machineId);
+        assertThat(objectNode.get("machineId").asText()).isEqualTo(Strings.isNullOrEmpty(vmInstanceMachineId) ? machineId : vmInstanceMachineId);
         assertThat(objectNode.get("numberOfClients").asInt()).isEqualTo(2);
         assertThat(objectNode.get("consistencyCfg").asText()).isEqualTo("(consistency: null, readConsistencyStrategy: null,  mm: false, prgns: [null])");
         assertThat(objectNode.get("connCfg").get("rntbd").asText()).isEqualTo("(cto:PT5S, nrto:PT5S, icto:PT0S, ieto:PT1H, mcpe:130, mrpc:30, cer:true)");
@@ -235,7 +238,7 @@ public void gw() throws Exception {
         ObjectNode objectNode = (ObjectNode) objectMapper.readTree(jsonWriter.toString());
 
         assertThat(objectNode.get("id").asInt()).isEqualTo(1);
-        assertThat(objectNode.get("machineId").asText()).isEqualTo(machineId);
+        assertThat(objectNode.get("machineId").asText()).isEqualTo(Strings.isNullOrEmpty(vmInstanceMachineId) ? machineId : vmInstanceMachineId);
         assertThat(objectNode.get("numberOfClients").asInt()).isEqualTo(2);
         assertThat(objectNode.get("consistencyCfg").asText()).isEqualTo("(consistency: null, readConsistencyStrategy: null,  mm: false, prgns: [null])");
         assertThat(objectNode.get("connCfg").get("rntbd").asText()).isEqualTo("null");
@@ -309,7 +312,7 @@ public void full(
         ObjectNode objectNode = (ObjectNode) objectMapper.readTree(jsonWriter.toString());
 
         assertThat(objectNode.get("id").asInt()).isEqualTo(1);
-        assertThat(objectNode.get("machineId").asText()).isEqualTo(machineId);
+        assertThat(objectNode.get("machineId").asText()).isEqualTo(Strings.isNullOrEmpty(vmInstanceMachineId) ? machineId : vmInstanceMachineId);
         assertThat(objectNode.get("numberOfClients").asInt()).isEqualTo(2);
         assertThat(objectNode.get("consistencyCfg").asText()).isEqualTo("(consistency: null, readConsistencyStrategy: null,  mm: false, prgns: [westus1,westus2])");
         assertThat(objectNode.get("connCfg").get("rntbd").asText()).isEqualTo("null");
@@ -362,7 +365,7 @@ public void sessionRetryOptionsInDiagnostics(SessionRetryOptions sessionRetryOpt
         ObjectNode objectNode = (ObjectNode) objectMapper.readTree(jsonWriter.toString());
 
         assertThat(objectNode.get("id").asInt()).isEqualTo(1);
-        assertThat(objectNode.get("machineId").asText()).isEqualTo(machineId);
+        assertThat(objectNode.get("machineId").asText()).isEqualTo(Strings.isNullOrEmpty(vmInstanceMachineId) ? machineId : vmInstanceMachineId);
         assertThat(objectNode.get("numberOfClients").asInt()).isEqualTo(2);
         assertThat(objectNode.get("consistencyCfg").asText()).isEqualTo("(consistency: null, readConsistencyStrategy: null,  mm: false, prgns: [null])");
         assertThat(objectNode.get("connCfg").get("rntbd").asText()).isEqualTo("null");

sdk/cosmos/azure-cosmos-tests/src/test/java/com/azure/cosmos/implementation/ImplementationBridgeHelpersTest.java

@@ -285,6 +285,106 @@ public static void main(String[] args) {
         }
     }
 
+    /**
+     * Regression test for the ClientTelemetry static-init failure when IMDS access is disabled.
+     * A fresh JVM is required so the system property is in effect before any Cosmos classes load.
+     */
+    @Test(groups = { "unit" })
+    public void cosmosClientBuildShouldSucceedWhenImdsAccessIsDisabled() throws Exception {
+        String javaHome = System.getProperty("java.home");
+        String javaBin = javaHome + java.io.File.separator + "bin" + java.io.File.separator + "java";
+        String classpath = System.getProperty("java.class.path");
+
+        List<String> command = new ArrayList<>();
+        command.add(javaBin);
+        command.add("-DCOSMOS.DISABLE_IMDS_ACCESS=true");
+
+        try {
+            int majorVersion = Integer.parseInt(System.getProperty("java.specification.version").split("\\.")[0]);
+            if (majorVersion >= 9) {
+                command.add("--add-opens");
+                command.add("java.base/java.lang=ALL-UNNAMED");
+            }
+        } catch (NumberFormatException e) {
+            // JDK 8
+        }
+
+        command.add("-cp");
+        command.add(classpath);
+        command.add(ClientTelemetryImdsDisabledChildProcess.class.getName());
+
+        ProcessBuilder pb = new ProcessBuilder(command);
+        pb.redirectErrorStream(true);
+        Process process = pb.start();
+
+        StringBuilder output = new StringBuilder();
+        Thread gobbler = new Thread(() -> {
+            try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
+                String line;
+                while ((line = reader.readLine()) != null) {
+                    output.append(line).append(System.lineSeparator());
+                    logger.info("[client-telemetry-imds-disabled] {}", line);
+                }
+            } catch (Exception e) {
+                // Process destroyed
+            }
+        });
+        gobbler.setDaemon(true);
+        gobbler.start();
+
+        boolean completed = process.waitFor(60, TimeUnit.SECONDS);
+        if (!completed) {
+            process.destroyForcibly();
+            gobbler.join(5000);
+            fail("ClientTelemetry IMDS-disabled regression check timed out after 60s. Output:\n" + output);
+        }
+
+        gobbler.join(5000);
+        int exitCode = process.exitValue();
+        assertThat(exitCode)
+            .as("Child JVM exited with non-zero code. Output:\n" + output)
+            .isEqualTo(0);
+    }
+
+    public static final class ClientTelemetryImdsDisabledChildProcess {
+        public static void main(String[] args) {
+            try {
+                com.azure.cosmos.CosmosAsyncClient client = new com.azure.cosmos.CosmosClientBuilder()
+                    .endpoint(TestConfigurations.HOST)
+                    .key(TestConfigurations.MASTER_KEY)
+                    .buildAsyncClient();
+
+                client.close();
+                System.out.println("Client built successfully with IMDS access disabled.");
+                System.exit(0);
+            } catch (Throwable throwable) {
+                if (containsClientTelemetryStaticInitFailure(throwable)) {
+                    throwable.printStackTrace(System.err);
+                    System.exit(1);
+                }
+
+                System.out.println("Client reached the expected network/auth path without a ClientTelemetry static-init failure.");
+                throwable.printStackTrace(System.out);
+                System.exit(0);
+            }
+        }
+
+        private static boolean containsClientTelemetryStaticInitFailure(Throwable throwable) {
+            Throwable current = throwable;
+            while (current != null) {
+                if (current instanceof ExceptionInInitializerError
+                    || current instanceof NoClassDefFoundError
+                    || (current.getMessage() != null && current.getMessage().contains("ClientTelemetry"))) {
+                    return true;
+                }
+
+                current = current.getCause();
+            }
+
+            return false;
+        }
+    }
+
     /**
      * Verifies that every {@code *Helper} inner class in
      * {@link ImplementationBridgeHelpers} has a resolvable accessor — i.e., calling

sdk/cosmos/azure-cosmos/CHANGELOG.md

@@ -12,6 +12,7 @@
 * Fixed JVM `<clinit>` deadlock when multiple threads concurrently trigger Cosmos SDK class loading for the first time. - See [PR 48689](https://github.com/Azure/azure-sdk-for-java/pull/48689)
 * Fixed an issue where `CustomItemSerializer` was incorrectly applied to internal SDK query pipeline structures (e.g., `OrderByRowResult`, `Document`), causing deserialization failures in ORDER BY, GROUP BY, aggregate, DISTINCT, and hybrid search queries. - See [PR 48811](https://github.com/Azure/azure-sdk-for-java/pull/48811)
 * Fixed an issue where `SqlParameter` ignored the configured `CustomItemSerializer`, always using the internal default serializer instead. - See [PR 48811](https://github.com/Azure/azure-sdk-for-java/pull/48811)
+* Fixed a `ClientTelemetry` static initialization failure when IMDS access is disabled, preventing `NoClassDefFoundError` during Cosmos client creation in non-Azure environments. - See [PR 48888](https://github.com/Azure/azure-sdk-for-java/pull/48888)
 
 #### Other Changes
 

sdk/cosmos/azure-cosmos/src/main/java/com/azure/cosmos/implementation/clienttelemetry/ClientTelemetry.java

@@ -51,17 +51,29 @@ private static ImplementationBridgeHelpers.CosmosClientTelemetryConfigHelper.Cos
     // - The fetch executes at most once
     // - All concurrent subscribers share the single result
     // - The HTTP client is created and disposed within the fetch
-    private static final Mono<AzureVMMetadata> CACHED_METADATA = fetchAzureVmMetadata().cache();
+    private static final Mono<AzureVMMetadata> CACHED_METADATA;
 
     // Sentinel for "not on Azure VM" or "IMDS unreachable"
-    private static final AzureVMMetadata METADATA_NOT_AVAILABLE = new AzureVMMetadata();
+    private static final AzureVMMetadata METADATA_NOT_AVAILABLE;
 
     // IMDS Constants
-    private static final String IMDS_AZURE_VM_METADATA = "http://169.254.169.254:80/metadata/instance?api-version=2020-06-01";
-    private static final Duration IMDS_DEFAULT_NETWORK_REQUEST_TIMEOUT = Duration.ofSeconds(5);
-    private static final Duration IMDS_DEFAULT_IDLE_CONNECTION_TIMEOUT = Duration.ofSeconds(60);
-    private static final Duration IMDS_DEFAULT_CONNECTION_ACQUIRE_TIMEOUT = Duration.ofSeconds(5);
-    private static final int IMDS_DEFAULT_MAX_CONNECTION_POOL_SIZE = 5;
+    private static final String IMDS_AZURE_VM_METADATA;
+    private static final Duration IMDS_DEFAULT_NETWORK_REQUEST_TIMEOUT;
+    private static final Duration IMDS_DEFAULT_IDLE_CONNECTION_TIMEOUT;
+    private static final Duration IMDS_DEFAULT_CONNECTION_ACQUIRE_TIMEOUT;
+    private static final int IMDS_DEFAULT_MAX_CONNECTION_POOL_SIZE;
+
+    static {
+        // Initialize the sentinel and IMDS defaults before creating the cached Mono,
+        // because fetchAzureVmMetadata() reads them during class initialization.
+        METADATA_NOT_AVAILABLE = new AzureVMMetadata();
+        IMDS_AZURE_VM_METADATA = "http://169.254.169.254:80/metadata/instance?api-version=2020-06-01";
+        IMDS_DEFAULT_NETWORK_REQUEST_TIMEOUT = Duration.ofSeconds(5);
+        IMDS_DEFAULT_IDLE_CONNECTION_TIMEOUT = Duration.ofSeconds(60);
+        IMDS_DEFAULT_CONNECTION_ACQUIRE_TIMEOUT = Duration.ofSeconds(5);
+        IMDS_DEFAULT_MAX_CONNECTION_POOL_SIZE = 5;
+        CACHED_METADATA = fetchAzureVmMetadata().cache();
+    }
 
     // Per-instance fields
     private final ClientTelemetryInfo clientTelemetryInfo;