Migration and Compatibility Testing

/**
 * Marker interface for migration tests
 * Used to categorize tests that verify version compatibility
 */
interface MigrationTest {
    // Marker interface - no methods
}

import org.apache.flink.test.util.MigrationTest;

public class MyStateMigrationTest implements MigrationTest {
    @Test
    public void testStateCompatibilityAcrossVersions() {
        // Migration test implementation
    }
}

/**
 * Generate snapshots for migration testing
 * Creates savepoints and checkpoints for compatibility testing
 */
class MigrationTestsSnapshotGenerator {
    /** Generate snapshot for current version */
    static void generateSnapshot(String snapshotPath, StreamExecutionEnvironment env) throws Exception;
    
    /** Generate snapshot with specific configuration */
    static void generateSnapshot(String snapshotPath, StreamExecutionEnvironment env, 
                               Configuration config) throws Exception;
    
    /** Validate snapshot format */
    static boolean validateSnapshotFormat(String snapshotPath);
    
    /** Get snapshot metadata */
    static SnapshotMetadata getSnapshotMetadata(String snapshotPath);
}

/**
 * Metadata about generated snapshots
 */
class SnapshotMetadata {
    /** Get Flink version that created the snapshot */
    String getFlinkVersion();
    
    /** Get checkpoint/savepoint timestamp */
    long getTimestamp();
    
    /** Get state backend information */
    String getStateBackend();
    
    /** Get operator state information */
    Map<String, OperatorState> getOperatorStates();
}

import org.apache.flink.test.migration.MigrationTestsSnapshotGenerator;

// Generate snapshot for current version
StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
// ... configure job with stateful operators
MigrationTestsSnapshotGenerator.generateSnapshot("/path/to/snapshot", env);

// Validate existing snapshot
boolean isValid = MigrationTestsSnapshotGenerator.validateSnapshotFormat("/path/to/old/snapshot");
assertTrue(isValid);

// Get snapshot information
SnapshotMetadata metadata = MigrationTestsSnapshotGenerator.getSnapshotMetadata("/path/to/snapshot");
System.out.println("Created by Flink version: " + metadata.getFlinkVersion());

/**
 * Utilities for working with published Flink versions
 * Helps manage version compatibility testing
 */
class PublishedVersionUtils {
    /** Get list of all published Flink versions */
    static List<String> getAllPublishedVersions();
    
    /** Get versions compatible with current version */
    static List<String> getCompatibleVersions();
    
    /** Check if version supports specific feature */
    static boolean supportsFeature(String version, String feature);
    
    /** Get version comparison result */
    static int compareVersions(String version1, String version2);
    
    /** Parse version string into components */
    static FlinkVersion parseVersion(String versionString);
}

/**
 * Structured representation of Flink version
 */
class FlinkVersion implements Comparable<FlinkVersion> {
    /** Get major version number */
    int getMajor();
    
    /** Get minor version number */
    int getMinor();
    
    /** Get patch version number */
    int getPatch();
    
    /** Get version string representation */
    String toString();
    
    /** Check if this version is newer than other */
    boolean isNewerThan(FlinkVersion other);
    
    int compareTo(FlinkVersion other);
}

/**
 * Utilities for snapshot generation and manipulation
 * Provides fine-grained control over snapshot creation
 */
class SnapshotGeneratorUtils {
    /** Create savepoint from running job */
    static String createSavepoint(JobID jobId, String savepointPath, ClusterClient<?> client) 
        throws Exception;
    
    /** Restore job from savepoint */
    static JobID restoreFromSavepoint(JobGraph jobGraph, String savepointPath, 
                                    ClusterClient<?> client) throws Exception;
    
    /** Convert checkpoint to savepoint */
    static void convertCheckpointToSavepoint(String checkpointPath, String savepointPath) 
        throws Exception;
    
    /** Validate savepoint compatibility */
    static boolean isCompatible(String savepointPath, JobGraph jobGraph);
    
    /** Extract operator state from snapshot */
    static Map<String, byte[]> extractOperatorState(String snapshotPath, String operatorId) 
        throws Exception;
    
    /** Create synthetic snapshot for testing */
    static void createSyntheticSnapshot(String snapshotPath, Map<String, Object> stateData) 
        throws Exception;
}