HDFS-17528. FsImageValidation: set txid when saving a new image

[szetszwo]

Description of PR

HDFS-17528

• When the fsimage is specified as a file and the FsImageValidation tool saves a new image (for removing inaccessible inodes), the txid is not set. Then, the resulted image will have 0 as its txid.
• When the fsimage is specified as a directory, the txid is set. However, it will get NPE since NameNode metrics is uninitialized (although the metrics is not used by FsImageValidation).

How was this patch tested?

Tested manually

• before: the output file is fsimage.ckpt_0000000000000000000 (i.e. txid is 0)

2024-05-14 13:37:27,531 [main] INFO namenode.FSImageFormatProtobuf (FSImageFormatProtobuf.java:save(732)) - Saving image file .../fsimage/current/newFsImage5968764763996132609/current/fsimage.ckpt_0000000000000000000 using no compression
2024-05-14 13:37:30,522 [main] INFO namenode.FSImageFormatProtobuf (FSImageFormatProtobuf.java:save(736)) - Image file .../fsimage/current/newFsImage5968764763996132609/current/fsimage.ckpt_0000000000000000000 of size 200392059 bytes saved in 2 seconds .

• after: the output file is fsimage.ckpt_0000000023945925442 with correct txid

2024-05-14 13:38:32,414 [main] INFO namenode.FSImage (FSImage.java:save(1223)) - save fsimage with txid=23945925442 to .../fsimage/current/newFsImage4409944859316006440
2024-05-14 13:38:32,436 [main] INFO namenode.FSImageFormatProtobuf (FSImageFormatProtobuf.java:save(732)) - Saving image file .../fsimage/current/newFsImage4409944859316006440/current/fsimage.ckpt_0000000023945925442 using no compression
2024-05-14 13:38:35,437 [main] INFO namenode.FSImageFormatProtobuf (FSImageFormatProtobuf.java:save(736)) - Image file .../fsimage/current/newFsImage4409944859316006440/current/fsimage.ckpt_0000000023945925442 of size 200392062 bytes saved in 3 seconds .

For code changes:

• Does the title or this PR starts with the corresponding JIRA issue id (e.g. 'HADOOP-17799. Your PR title ...')?
• [NA] Object storage: have the integration tests been executed and the endpoint declared according to the connector-specific documentation?
• [NA] If adding new dependencies to the code, are these dependencies licensed in a way that is compatible for inclusion under ASF 2.0?
• [NA] If applicable, have you updated the LICENSE, LICENSE-binary, NOTICE-binary files?

[szetszwo]

@vinayakumarb , thanks a lot for reviewing this!

[szetszwo]

The jenkins builds keep getting stuck for a day and then fail. Not sure if it is a known problem?

[szetszwo]

The last few lines of the Jenkins build before failure:

[2024-06-03T20:14:42.551Z] cd /home/jenkins/jenkins-home/workspace/hadoop-multibranch_PR-6828/ubuntu-focal/src/hadoop-hdfs-project/hadoop-hdfs
[2024-06-03T20:14:42.551Z] /usr/bin/mvn --batch-mode -Dmaven.repo.local=/home/jenkins/jenkins-home/workspace/hadoop-multibranch_PR-6828/yetus-m2/hadoop-trunk-patch-0 -Dsurefire.rerunFailingTestsCount=2 -Pparallel-tests -P!shelltest -Pnative -Drequire.fuse -Drequire.openssl -Drequire.snappy -Drequire.valgrind -Drequire.zstd -Drequire.test.libhadoop -Pyarn-ui clean test -fae > /home/jenkins/jenkins-home/workspace/hadoop-multibranch_PR-6828/ubuntu-focal/out/patch-unit-hadoop-hdfs-project_hadoop-hdfs.txt 2>&1
[2024-06-05T05:43:40.181Z] wrapper script does not seem to be touching the log file in /home/jenkins/jenkins-home/workspace/hadoop-multibranch_PR-6828@tmp/durable-db261340
[2024-06-05T05:43:40.181Z] (JENKINS-48300: if on an extremely laggy filesystem, consider -Dorg.jenkinsci.plugins.durabletask.BourneShellScript.HEARTBEAT_CHECK_INTERVAL=86400)
script returned exit code -1