IGNITE-26762 Use separate folders for index and segment files (#6803)

Author: sashapolo

modules/raft/src/main/java/org/apache/ignite/internal/raft/storage/segstore/IndexFileManager.java

@@ -100,7 +100,7 @@ class IndexFileManager {
 
     static final ByteOrder BYTE_ORDER = ByteOrder.LITTLE_ENDIAN;
 
-    private final Path baseDir;
+    private final Path indexFilesDir;
 
     /**
      * Current index file ordinal (used to generate index file names).
@@ -114,8 +114,14 @@ class IndexFileManager {
      */
     private final Map<Long, GroupIndexMeta> groupIndexMetas = new ConcurrentHashMap<>();
 
-    IndexFileManager(Path baseDir) {
-        this.baseDir = baseDir;
+    IndexFileManager(Path baseDir) throws IOException {
+        indexFilesDir = baseDir.resolve("index");
+
+        Files.createDirectories(indexFilesDir);
+    }
+
+    Path indexFilesDir() {
+        return indexFilesDir;
     }
 
     /**
@@ -124,7 +130,7 @@ class IndexFileManager {
     Path saveIndexMemtable(ReadModeIndexMemTable indexMemTable) throws IOException {
         String fileName = indexFileName(curFileOrdinal, 0);
 
-        Path tmpFilePath = baseDir.resolve(fileName + ".tmp");
+        Path tmpFilePath = indexFilesDir.resolve(fileName + ".tmp");
 
         try (var os = new BufferedOutputStream(Files.newOutputStream(tmpFilePath, CREATE_NEW, WRITE))) {
             byte[] headerBytes = serializeHeaderAndFillMetadata(indexMemTable);
@@ -161,7 +167,7 @@ SegmentFilePointer getSegmentFilePointer(long groupId, long logIndex) throws IOE
             return null;
         }
 
-        Path indexFile = baseDir.resolve(indexFileName(indexFileMeta.indexFileOrdinal(), 0));
+        Path indexFile = indexFilesDir.resolve(indexFileName(indexFileMeta.indexFileOrdinal(), 0));
 
         // Index file payload is a 0-based array, which indices correspond to the [fileMeta.firstLogIndex, fileMeta.lastLogIndex) range.
         long payloadArrayIndex = logIndex - indexFileMeta.firstLogIndexInclusive();

modules/raft/src/main/java/org/apache/ignite/internal/raft/storage/segstore/SegmentFileManager.java

@@ -22,6 +22,7 @@
 
 import java.io.IOException;
 import java.nio.ByteBuffer;
+import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.concurrent.atomic.AtomicReference;
 import org.apache.ignite.internal.close.ManuallyCloseable;
@@ -90,7 +91,7 @@ class SegmentFileManager implements ManuallyCloseable {
      */
     static final byte[] SWITCH_SEGMENT_RECORD = new byte[8]; // 8 zero bytes.
 
-    private final Path baseDir;
+    private final Path segmentFilesDir;
 
     /** Configured size of a segment file. */
     private final long fileSize;
@@ -124,12 +125,15 @@ class SegmentFileManager implements ManuallyCloseable {
      */
     private boolean isStopped;
 
-    SegmentFileManager(String nodeName, Path baseDir, long fileSize, int stripes, FailureProcessor failureProcessor) {
+    SegmentFileManager(String nodeName, Path baseDir, long fileSize, int stripes, FailureProcessor failureProcessor) throws IOException {
         if (fileSize <= HEADER_RECORD.length) {
             throw new IllegalArgumentException("File size must be greater than the header size: " + fileSize);
         }
 
-        this.baseDir = baseDir;
+        this.segmentFilesDir = baseDir.resolve("segments");
+
+        Files.createDirectories(segmentFilesDir);
+
         this.fileSize = fileSize;
         this.stripes = stripes;
 
@@ -144,8 +148,16 @@ void start() throws IOException {
         currentSegmentFile.set(allocateNewSegmentFile(0));
     }
 
+    Path segmentFilesDir() {
+        return segmentFilesDir;
+    }
+
+    Path indexFilesDir() {
+        return indexFileManager.indexFilesDir();
+    }
+
     private SegmentFileWithMemtable allocateNewSegmentFile(int fileOrdinal) throws IOException {
-        Path path = baseDir.resolve(segmentFileName(fileOrdinal, 0));
+        Path path = segmentFilesDir.resolve(segmentFileName(fileOrdinal, 0));
 
         SegmentFile segmentFile = SegmentFile.createNew(path, fileSize);
 
@@ -385,7 +397,7 @@ private long maxEntrySize() {
             return null;
         }
 
-        Path path = baseDir.resolve(segmentFileName(segmentFilePointer.fileOrdinal(), 0));
+        Path path = segmentFilesDir.resolve(segmentFileName(segmentFilePointer.fileOrdinal(), 0));
 
         // TODO: Add a cache for recently accessed segment files, see https://issues.apache.org/jira/browse/IGNITE-26622.
         SegmentFile segmentFile = SegmentFile.openExisting(path);

modules/raft/src/test/java/org/apache/ignite/internal/raft/storage/segstore/IndexFileManagerTest.java

@@ -36,7 +36,7 @@ class IndexFileManagerTest extends IgniteAbstractTest {
     private IndexFileManager indexFileManager;
 
     @BeforeEach
-    void setUp() {
+    void setUp() throws IOException {
         indexFileManager = new IndexFileManager(workDir);
     }
 
@@ -48,9 +48,9 @@ void testIndexFileNaming() throws IOException {
         Path path1 = indexFileManager.saveIndexMemtable(memtable);
         Path path2 = indexFileManager.saveIndexMemtable(memtable);
 
-        assertThat(path0, is(workDir.resolve("index-0000000000-0000000000.bin")));
-        assertThat(path1, is(workDir.resolve("index-0000000001-0000000000.bin")));
-        assertThat(path2, is(workDir.resolve("index-0000000002-0000000000.bin")));
+        assertThat(path0, is(indexFileManager.indexFilesDir().resolve("index-0000000000-0000000000.bin")));
+        assertThat(path1, is(indexFileManager.indexFilesDir().resolve("index-0000000001-0000000000.bin")));
+        assertThat(path2, is(indexFileManager.indexFilesDir().resolve("index-0000000002-0000000000.bin")));
     }
 
     @Test

modules/raft/src/test/java/org/apache/ignite/internal/raft/storage/segstore/SegmentFileManagerTest.java

@@ -376,21 +376,18 @@ private Path findSoleSegmentFile() throws IOException {
     }
 
     private List<Path> segmentFiles() throws IOException {
-        try (Stream<Path> files = Files.list(workDir)) {
-            return files
-                    .filter(p -> p.getFileName().toString().startsWith("segment"))
-                    .sorted()
-                    .collect(toList());
+        try (Stream<Path> files = Files.list(fileManager.segmentFilesDir())) {
+            return files.sorted().collect(toList());
         }
     }
 
     private List<Path> indexFiles() throws IOException {
-        try (Stream<Path> files = Files.list(workDir)) {
+        try (Stream<Path> files = Files.list(fileManager.indexFilesDir())) {
             return files
                     .filter(p -> {
                         String fileName = p.getFileName().toString();
 
-                        return fileName.startsWith("index") && !fileName.endsWith(".tmp");
+                        return !fileName.endsWith(".tmp");
                     })
                     .sorted()
                     .collect(toList());

modules/raft/src/test/java/org/apache/ignite/internal/raft/storage/segstore/SegstoreLogStorageTest.java

@@ -42,11 +42,11 @@ void tearDown() throws Exception {
 
     @Override
     protected LogStorage newLogStorage() {
-        segmentFileManager = new SegmentFileManager(NODE_NAME, path, SEGMENT_SIZE, 1, new NoOpFailureManager());
+        try {
+            segmentFileManager = new SegmentFileManager(NODE_NAME, path, SEGMENT_SIZE, 1, new NoOpFailureManager());
 
-        logStorage = new SegstoreLogStorage(GROUP_ID, segmentFileManager);
+            logStorage = new SegstoreLogStorage(GROUP_ID, segmentFileManager);
 
-        try {
             segmentFileManager.start();
         } catch (IOException e) {
             throw new RuntimeException(e);