Details
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Bug
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Status: Resolved
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Low
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Resolution: Fixed
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None
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None
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Cassandra 1.2.12
CentOS 6.4
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Low
Description
Synopsis: misbehaving clients can cause DoS on a cluster with a defunct prepared statement
Scenario:
1.) Create prepared INSERT statement on existing table X
2.) Table X is dropped
3.) Continue using prepared statement from (1)
Result:
a.) on coordinator node: COMMIT-LOG-WRITER + MutationStage errors
b.) on other nodes: "UnknownColumnFamilyException reading from socket; closing" --> leads to thrashing inter-node connections
c.) Other clients of the cluster suffer from I/O timeouts, presumably a result of (b)
Other observations:
- On single-node clusters, clients return from insert without error because mutation errors are swallowed.
- On multiple-node clusters, clients receive a confounded 'read timeout' error because the closed internode connections do not propagate the error back.
- With prepared SELECT statements (as opposed to INSERT described above). A NullPointerException is caused on the server, and no meaninful error is returned to the client.
Besides the obvious "don't do that" to the integrator, it would be good if the cluster could handle this error case more gracefully and avoid undue impact.