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https://issues.apache.org/jira/browse/HADOOP-7550?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Allen Wittenauer updated HADOOP-7550:
-------------------------------------
Labels: ipv6 (was: )
> Need for Integrity Validation of RPC
> ------------------------------------
>
> Key: HADOOP-7550
> URL: https://issues.apache.org/jira/browse/HADOOP-7550
> Project: Hadoop Common
> Issue Type: Improvement
> Components: ipc
> Reporter: Dave Thompson
> Assignee: Dave Thompson
> Labels: ipv6
>
> Some recent investigation of network packet corruption has shown a need for
> hadoop RPC integrity validation beyond assurances already provided by 802.3
> link layer and TCP 16-bit CRC.
> During an unusual occurrence on a 4k node cluster, we've seen as high as 4
> TCP anomalies per second on a single node, sustained over an hour (14k per
> hour). A TCP anomaly would be an escaped link layer packet that resulted
> in a TCP CRC failure, TCP packet out of sequence
> or TCP packet size error.
> According to this paper[*]: http://tinyurl.com/3aue72r
> TCP's 16-bit CRC has an effective detection rate of 2^10. 1 in 1024 errors
> may escape detection, and in fact what originally alerted us to this issue
> was seeing failures due to bit-errors in hadoop traffic. Extrapolating from
> that paper, one might expect 14 escaped packet errors per hour for that
> single node of a 4k cluster. While the above error rate
> was unusually high due to a broadband aggregate switch issue, hadoop not
> having an integrity check on RPC makes it problematic to discover, and limit
> any potential data damage due to
> acting on a corrupt RPC message.
> ------
> [*] In case this jira outlives that tinyurl, the IEEE paper cited is:
> "Performance of Checksums and CRCs over Real Data" by Jonathan Stone, Michael
> Greenwald, Craig Partridge, Jim Hughes.
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