HDDS-10822. Tool to omit raft log in OM. (apache#8154)

Author: Tejaskriya

hadoop-ozone/tools/src/main/java/org/apache/hadoop/ozone/repair/om/OMRatisLogRepair.java

@@ -0,0 +1,217 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You 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 org.apache.hadoop.ozone.repair.om;
+
+import static org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos.Type.EchoRPC;
+
+import java.io.File;
+import java.io.IOException;
+import java.nio.ByteBuffer;
+import java.nio.file.Files;
+import java.nio.file.StandardCopyOption;
+import java.util.regex.Matcher;
+import java.util.regex.Pattern;
+import org.apache.hadoop.hdds.cli.HddsVersionProvider;
+import org.apache.hadoop.ozone.om.helpers.OMRatisHelper;
+import org.apache.hadoop.ozone.protocol.proto.OzoneManagerProtocolProtos;
+import org.apache.hadoop.ozone.repair.RepairTool;
+import org.apache.ratis.proto.RaftProtos;
+import org.apache.ratis.server.RaftServerConfigKeys;
+import org.apache.ratis.server.raftlog.segmented.LogSegment;
+import org.apache.ratis.server.raftlog.segmented.LogSegmentPath;
+import org.apache.ratis.server.raftlog.segmented.SegmentedRaftLogOutputStream;
+import org.apache.ratis.util.SizeInBytes;
+import picocli.CommandLine;
+
+/**
+ * Tool to omit a raft log in a ratis segment file.
+ */
+@CommandLine.Command(
+    name = "skip-ratis-transaction",
+    aliases = "srt",
+    description = "CLI to omit a raft log in a ratis segment file. The raft log at the index specified " +
+        "is replaced with an EchoOM command (which is a dummy command). It is an offline command " +
+        "i.e., doesn't require OM to be running. " +
+        "The command should be run for the same transaction on all 3 OMs only when all the OMs are crashing " +
+        "while applying the same transaction. If only one OM is crashing and the " +
+        "other OMs have executed the log successfully, then the DB should be manually copied " +
+        "from one of the good OMs to the crashing OM instead.",
+    mixinStandardHelpOptions = true,
+    versionProvider = HddsVersionProvider.class
+)
+public class OMRatisLogRepair extends RepairTool {
+
+  @CommandLine.ArgGroup(multiplicity = "1")
+  private ExclusiveArguments exclusiveArguments;
+
+  @CommandLine.Option(names = {"-b", "--backup"},
+      required = true,
+      description = "Directory to put the backup of the original repaired segment file before the repair.")
+  private File backupDir;
+
+  @CommandLine.Option(names = {"--index"},
+      required = true,
+      description = "Index of the failing transaction that should be removed")
+  private long index;
+
+  private SegmentedRaftLogOutputStream outputStream = null;
+
+  @Override
+  public void execute() throws Exception {
+
+    if (exclusiveArguments.logDir != null) {
+      exclusiveArguments.segmentFile = findSegmentFileContainingIndex();
+    }
+
+    if (exclusiveArguments.segmentFile.getParentFile().toPath().equals(backupDir.toPath())) {
+      throw new IOException("Backup directory cannot be same as segment file's parent directory.");
+    }
+
+    LogSegmentPath pi = LogSegmentPath.matchLogSegment(this.exclusiveArguments.segmentFile.toPath());
+    if (pi == null) {
+      throw new IOException("Invalid Segment File");
+    }
+
+    if (!exclusiveArguments.segmentFile.exists()) {
+      throw new IOException("Error: Source segment file \"" + exclusiveArguments.segmentFile + "\" does not exist.");
+    }
+    if (!backupDir.exists()) {
+      info("BackupDir \"" + backupDir + "\" does not exist. Creating the directory path.");
+      if (!isDryRun()) {
+        Files.createDirectories(backupDir.toPath());
+      }
+    }
+
+    File backupPath = new File(backupDir, exclusiveArguments.segmentFile.getName());
+    if (backupPath.exists()) {
+      throw new IOException("Error: Backup file for segment file  \"" + exclusiveArguments.segmentFile +
+          "\" already exists. Either delete the old backup or provide a different directory to take the backup.");
+    }
+    info("Taking back up of Raft Log file: " + this.exclusiveArguments.segmentFile.getAbsolutePath() +
+        " to location: " + backupPath);
+    if (!isDryRun()) {
+      Files.copy(exclusiveArguments.segmentFile.toPath(), backupPath.toPath());
+    }
+    info("File backed-up successfully!");
+
+    File outputFile = null;
+    if (!isDryRun()) {
+      outputFile = File.createTempFile("srt-output", null, backupDir);
+      outputFile.deleteOnExit();
+    }
+    info("Created temporary output file: " + (outputFile == null ? "<None>" : outputFile.toPath()));
+
+    info("Processing Raft Log file: " + this.exclusiveArguments.segmentFile.getAbsolutePath() + " size:" +
+        this.exclusiveArguments.segmentFile.length());
+
+    if (!isDryRun()) {
+      outputStream = new SegmentedRaftLogOutputStream(outputFile, false,
+          1024, 1024, ByteBuffer.allocateDirect(SizeInBytes.valueOf("8MB").getSizeInt()));
+    }
+
+    int entryCount = LogSegment.readSegmentFile(exclusiveArguments.segmentFile, pi.getStartEnd(),
+        SizeInBytes.valueOf("32MB"), RaftServerConfigKeys.Log.CorruptionPolicy.EXCEPTION, null, this::processLogEntry);
+    if (!isDryRun()) {
+      outputStream.flush();
+      outputStream.close();
+      Files.move(outputFile.toPath(), exclusiveArguments.segmentFile.toPath(),
+          StandardCopyOption.REPLACE_EXISTING, StandardCopyOption.ATOMIC_MOVE);
+    }
+    info("Finished processing all the entries (" + entryCount + " logs) from the segment file.");
+    info("Moved temporary output file to correct raft log location : " + exclusiveArguments.segmentFile.toPath());
+
+  }
+
+  private void processLogEntry(RaftProtos.LogEntryProto proto) {
+    try {
+      RaftProtos.LogEntryProto newLogEntry = proto.getIndex() != index ? proto : getOmEchoLogEntry(proto);
+      if (!isDryRun()) {
+        outputStream.write(newLogEntry);
+        outputStream.flush();
+      }
+    } catch (IOException ex) {
+      throw new RuntimeException("Error while processing logEntry: (" + proto.getIndex() + "). Exception: " + ex);
+    }
+  }
+
+  private RaftProtos.LogEntryProto getOmEchoLogEntry(RaftProtos.LogEntryProto proto) throws IOException {
+    OzoneManagerProtocolProtos.OMRequest.Builder newRequest = OzoneManagerProtocolProtos.OMRequest.newBuilder()
+        .setCmdType(EchoRPC)
+        .setClientId("skip-ratis-transaction-repair-tool")
+        .setEchoRPCRequest(OzoneManagerProtocolProtos.EchoRPCRequest.newBuilder().build());
+    RaftProtos.StateMachineLogEntryProto.Builder entry =  proto.getStateMachineLogEntry().toBuilder()
+        .setLogData(OMRatisHelper.convertRequestToByteString(newRequest.build()));
+    OzoneManagerProtocolProtos.OMRequest oldRequest = OMRatisHelper
+        .convertByteStringToOMRequest(proto.getStateMachineLogEntry().getLogData());
+    info("Replacing {" + oldRequest.toString().replace("\n", "  ")
+        + "} with EchoRPC command at index " + proto.getIndex());
+    return proto.toBuilder()
+        .setStateMachineLogEntry(entry)
+        .build();
+  }
+
+  private File findSegmentFileContainingIndex() {
+    if (!exclusiveArguments.logDir.exists() || !exclusiveArguments.logDir.isDirectory()) {
+      throw new IllegalArgumentException("Invalid log directory: " + exclusiveArguments.logDir);
+    }
+
+    // Pattern to match Ratis log files: log_<start>-<end> or log_inprogress_<start>
+    Pattern pattern = Pattern.compile("log(?:_inprogress)?_(\\d+)(?:-(\\d+))?");
+
+    File[] segmentFiles = exclusiveArguments.logDir.listFiles();
+    if (segmentFiles == null) {
+      throw new IllegalArgumentException("Invalid log directory: " + exclusiveArguments.logDir +
+          ". No segment files present.");
+    }
+
+    for (File file : segmentFiles) {
+      Matcher matcher = pattern.matcher(file.getName());
+      if (matcher.matches()) {
+        long start = Long.parseLong(matcher.group(1));
+        String endStr = matcher.group(2);
+
+        // If it's an in-progress file, assume it contains all entries from start onwards
+        if (endStr == null) {
+          if (index >= start) {
+            info("Segment file \"" + file + "\" contains the index (" + index + ").");
+            return file;
+          }
+        } else {
+          long end = Long.parseLong(endStr);
+          if (index >= start && index <= end) {
+            info("Segment file \"" + file + "\" contains the index (" + index + ").");
+            return file;
+          }
+        }
+      }
+    }
+
+    throw new IllegalArgumentException("Invalid index (" + index
+        + ") for log directory: \"" + exclusiveArguments.logDir + "\". None of the segment files have the index.");
+  }
+
+  private static final class ExclusiveArguments {
+    @CommandLine.Option(names = {"-s", "--segment-path"},
+        description = "Path of the input segment file")
+    private File segmentFile;
+
+    @CommandLine.Option(names = {"-d", "--ratis-log-dir"},
+        description = "Path of the ratis log directory")
+    private File logDir;
+  }
+}

hadoop-ozone/tools/src/main/java/org/apache/hadoop/ozone/repair/om/OMRepair.java

@@ -32,7 +32,8 @@
         SnapshotRepair.class,
         TransactionInfoRepair.class,
         QuotaRepair.class,
-        CompactOMDB.class
+        CompactOMDB.class,
+        OMRatisLogRepair.class
     },
     description = "Operational tool to repair OM.")
 @MetaInfServices(RepairSubcommand.class)