[CASSANDRA-10534] CompressionInfo not being fsynced on close

• Type: Bug
• Status: Resolved
• Priority: Normal
• Resolution: Fixed
• Fix Version/s: 2.1.12, 2.2.4, 3.0.1, 3.1
• Component/s: Legacy/Local Write-Read Paths
• Severity: Normal
• Assignee: Stefania Alborghetti
• Reporter: Sharvanath Pathak

Authors

Stefania Alborghetti

Reviewers

Ariel Weisberg

• Created: 15/Oct/15 14:28
• Updated: 16/Apr/19 09:30
• Resolved: 13/Nov/15 14:59

Description

I was seeing SSTable corruption due to a CompressionInfo.db file of size 0, this happened multiple times in our testing with hard node reboots. After some investigation it seems like these file is not being fsynced, and that can potentially lead to data corruption. I am working with version 2.1.9.

I checked for fsync calls using strace, and found them happening for all but the following components: CompressionInfo, TOC.txt and digest.sha1. All of these but the CompressionInfo seem tolerable. Also a quick look through the code did not reveal any fsync calls. Moreover, I suspect the commit 4e95953f29d89a441dfe06d3f0393ed7dd8586df (https://github.com/apache/cassandra/commit/4e95953f29d89a441dfe06d3f0393ed7dd8586df#diff-b7e48a1398e39a936c11d0397d5d1966R344) has caused the regression, which removed the line

 getChannel().force(true);

from CompressionMetadata.Writer.close.

Following is the trace I saw in system.log:

INFO  [SSTableBatchOpen:1] 2015-09-29 19:24:39,170 SSTableReader.java:478 - Opening /var/lib/cassandra/data/system/compactions_in_progress-55080ab05d9c388690a4acb25fe1f77b/system-compactions_in_progress-ka-13368 (79 bytes)
ERROR [SSTableBatchOpen:1] 2015-09-29 19:24:39,177 FileUtils.java:447 - Exiting forcefully due to file system exception on startup, disk failure policy "stop"
org.apache.cassandra.io.sstable.CorruptSSTableException: java.io.EOFException
        at org.apache.cassandra.io.compress.CompressionMetadata.<init>(CompressionMetadata.java:131) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.compress.CompressionMetadata.create(CompressionMetadata.java:85) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.util.CompressedSegmentedFile$Builder.metadata(CompressedSegmentedFile.java:79) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.util.CompressedPoolingSegmentedFile$Builder.complete(CompressedPoolingSegmentedFile.java:72) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.util.SegmentedFile$Builder.complete(SegmentedFile.java:168) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.sstable.SSTableReader.load(SSTableReader.java:752) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.sstable.SSTableReader.load(SSTableReader.java:703) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:491) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.sstable.SSTableReader.open(SSTableReader.java:387) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at org.apache.cassandra.io.sstable.SSTableReader$4.run(SSTableReader.java:534) ~[apache-cassandra-2.1.9.jar:2.1.9]
        at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:471) [na:1.7.0_80]
        at java.util.concurrent.FutureTask.run(FutureTask.java:262) [na:1.7.0_80]
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1145) [na:1.7.0_80]
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:615) [na:1.7.0_80]
        at java.lang.Thread.run(Thread.java:745) [na:1.7.0_80]
Caused by: java.io.EOFException: null
        at java.io.DataInputStream.readUnsignedShort(DataInputStream.java:340) ~[na:1.7.0_80]
        at java.io.DataInputStream.readUTF(DataInputStream.java:589) ~[na:1.7.0_80]
        at java.io.DataInputStream.readUTF(DataInputStream.java:564) ~[na:1.7.0_80]
        at org.apache.cassandra.io.compress.CompressionMetadata.<init>(CompressionMetadata.java:106) ~[apache-cassandra-2.1.9.jar:2.1.9]
        ... 14 common frames omitted

Following is the result of ls on the data directory of a corrupted SSTable after the hard reboot:

$ ls -l /var/lib/cassandra/data/system/sstable_activity-5a1ff267ace03f128563cfae6103c65e/
total 60
-rw-r--r-- 1 cassandra cassandra     0 Oct 15 09:31 system-sstable_activity-ka-1-CompressionInfo.db
-rw-r--r-- 1 cassandra cassandra  9740 Oct 15 09:31 system-sstable_activity-ka-1-Data.db
-rw-r--r-- 1 cassandra cassandra     0 Oct 15 09:31 system-sstable_activity-ka-1-Digest.sha1
-rw-r--r-- 1 cassandra cassandra   880 Oct 15 09:31 system-sstable_activity-ka-1-Filter.db
-rw-r--r-- 1 cassandra cassandra 34000 Oct 15 09:31 system-sstable_activity-ka-1-Index.db
-rw-r--r-- 1 cassandra cassandra  7338 Oct 15 09:31 system-sstable_activity-ka-1-Statistics.db
-rw-r--r-- 1 cassandra cassandra     0 Oct 15 09:31 system-sstable_activity-ka-1-TOC.txt

Issue Links

• is broken by: CASSANDRA-6916 Preemptive opening of compaction result
• is cloned by: CASSANDRA-10479 Handling partially written sstables on node crashes
• is related to: CASSANDRA-10709 Synchronize TOC and digest
• is related to: CASSANDRA-10710 Power failure testing
• links to: 2.1 patch
• links to: 2.2 patch