Hi,
it's not only performance issue. In case of network problem writer tread can be blocked, also in case of failure loss of data can occur. Best regards, Vladimir Yudovin, Winguzone - Hosted Cloud Cassandra Launch your cluster in minutes. ---- On Tue, 01 Nov 2016 14:10:10 -0400John Sanda <john.sa...@gmail.com> wrote ---- I know that using NFS is discouraged, particularly for the commit log. Can anyone shed some light into what kinds of problems I might encounter aside from performance? The reason for my inquiry is because I have some deployments with Cassandra 2.2.1 that use NFS and are experiencing some problems like reoccurring corrupted commit log segments on start up: ERROR 19:38:42 Exiting due to error while processing commit log during initialization. org.apache.cassandra.db.commitlog.CommitLogReplayer$CommitLogReplayException: Mutation checksum failure at 33296351 in CommitLog-5-1474325237114.log at org.apache.cassandra.db.commitlog.CommitLogReplayer.handleReplayError(CommitLogReplayer.java:622) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.db.commitlog.CommitLogReplayer.replaySyncSection(CommitLogReplayer.java:492) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.db.commitlog.CommitLogReplayer.recover(CommitLogReplayer.java:388) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.db.commitlog.CommitLogReplayer.recover(CommitLogReplayer.java:147) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.db.commitlog.CommitLog.recover(CommitLog.java:189) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.db.commitlog.CommitLog.recover(CommitLog.java:169) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:266) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:488) [apache-cassandra-2.2.1.jar] at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:595) [apache-cassandra-2.2.1.jar] In one deployment after removing all of corrupted commit log segments I got a different error: Exception (java.lang.RuntimeException) encountered during startup: java.nio.file.NoSuchFileException: /cassandra_data/data/hawkular_metrics/metrics_idx-1ea881506ee311e6890b131c1bc89929/la-86-big-Statistics.db java.lang.RuntimeException: java.nio.file.NoSuchFileException: /cassandra_data/data/hawkular_metrics/metrics_idx-1ea881506ee311e6890b131c1bc89929/la-86-big-Statistics.db at org.apache.cassandra.io.util.ChannelProxy.openChannel(ChannelProxy.java:55) at org.apache.cassandra.io.util.ChannelProxy.<init>(ChannelProxy.java:66) at org.apache.cassandra.io.util.RandomAccessReader.open(RandomAccessReader.java:78) at org.apache.cassandra.io.sstable.metadata.MetadataSerializer.deserialize(MetadataSerializer.java:91) at org.apache.cassandra.io.sstable.metadata.MetadataSerializer.deserialize(MetadataSerializer.java:101) at org.apache.cassandra.db.ColumnFamilyStore.removeUnfinishedCompactionLeftovers(ColumnFamilyStore.java:672) at org.apache.cassandra.service.CassandraDaemon.setup(CassandraDaemon.java:216) at org.apache.cassandra.service.CassandraDaemon.activate(CassandraDaemon.java:488) at org.apache.cassandra.service.CassandraDaemon.main(CassandraDaemon.java:595) Caused by: java.nio.file.NoSuchFileException: /cassandra_data/data/hawkular_metrics/metrics_idx-1ea881506ee311e6890b131c1bc89929/la-86-big-Statistics.db at sun.nio.fs.UnixException.translateToIOException(UnixException.java:86) at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:102) at sun.nio.fs.UnixException.rethrowAsIOException(UnixException.java:107) at sun.nio.fs.UnixFileSystemProvider.newFileChannel(UnixFileSystemProvider.java:177) at java.nio.channels.FileChannel.open(FileChannel.java:287) at java.nio.channels.FileChannel.open(FileChannel.java:335) at org.apache.cassandra.io.util.ChannelProxy.openChannel(ChannelProxy.java:51) ... 8 more The latter error looks like it involves compaction and might be unrelated. I don't know if it matters, but I have commit log compression enabled in these environments. -- - John
