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Apache Cassandra fails to start with "FSReadError" and ""


In some instances, an exception is encounter during startup of Apache Cassandra, in particular when attempting to read a temporary (*-tmp-*) data file.


During startup, returns an exception while reading a "tmp" file.

Here is a sample exception stack trace from DSE 4.6.1:

ERROR [main] 2015-05-14 22:08:52,560 (line 513) Exception encountered during startup
FSReadError in /var/lib/cassandra/data/appKS/userCF-tmp-jb-2-Statistics.db
        at org.apache.cassandra.db.ColumnFamilyStore.removeUnfinishedCompactionLeftovers(
        at org.apache.cassandra.service.CassandraDaemon.setup(
        at com.datastax.bdp.server.DseDaemon.setup(
        at org.apache.cassandra.service.CassandraDaemon.activate(
        at com.datastax.bdp.server.DseDaemon.main(
Caused by:
        at org.apache.cassandra.utils.EstimatedHistogram$EstimatedHistogramSerializer.deserialize(
        at org.apache.cassandra.db.ColumnFamilyStore.removeUnfinishedCompactionLeftovers(
        ... 4 more
 INFO [Thread-2] 2015-05-14 22:08:52,564 (line 502) DSE shutting down...


Temporary data files are created during normal compaction operations. In this instance, the temp file was leftover from a failed compaction. The compaction failure could be the result of the following:

  • unclean shutdown of DSE, e.g. forced kill
  • unexpected node outage, e.g. hardware failure or power outage
  • server reboot without DSE being shutdown

In addition to the above, the offending files have a zero (0) byte size resulting in


Follow the steps below to recover the node:

Step 1 - Delete the offending file and its associated files. In the example above, the file is userCF-tmp-jb-2-Statistics.db so delete all "sequence 2" files (userCF-tmp-jb-2-*.db).

Step 2 - Start DSE.


Where a node outage is planned, ensure that DSE is shutdown cleanly before shutting down or rebooting the node.

For unplanned outages, recover the node by following the steps in the Workaround above.

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