[jira] [Commented] (FLINK-9940) File source continuous monitoring mode: S3 files sometimes missed

["Vasii Cosmin Radu (Jira)" <ji...@apache.org>]

    [ https://issues.apache.org/jira/browse/FLINK-9940?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17258684#comment-17258684 ] 

Vasii Cosmin Radu commented on FLINK-9940:
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Hi there, [~maguowei], [~Averell], [~kkl0u], [~juanmirocks],

S3 delivers now string read-after-write consistency: [https://aws.amazon.com/s3/consistency/]. Is this issue still valid?

> File source continuous monitoring mode: S3 files sometimes missed
> -----------------------------------------------------------------
>
>                 Key: FLINK-9940
>                 URL: https://issues.apache.org/jira/browse/FLINK-9940
>             Project: Flink
>          Issue Type: Bug
>          Components: API / DataStream
>    Affects Versions: 1.5.1
>         Environment: Flink 1.5, EMRFS
>            Reporter: Huyen Levan
>            Assignee: Huyen Levan
>            Priority: Major
>              Labels: EMRFS, Flink, S3, pull-request-available
>
> When using StreamExecutionEnvironment.readFile() with FileProcessingMode.PROCESS_CONTINUOUSLY mode to monitor an S3 prefix, if there is a high amount of new/modified files at the same time, the directory monitoring process might miss some files. The number of missing files depends on the monitoring interval.
> Cause: Flink tracks which files it has read by remembering the modification time of the file that was added (or modified) last. So when there are multiple files having a same last-modified timestamp.
> Suggested solution (thanks to [[Fabian Hueske|http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/template/NamlServlet.jtp?macro=user_nodes&user=25]|http://apache-flink-user-mailing-list-archive.2336050.n4.nabble.com/template/NamlServlet.jtp?macro=user_nodes&user=25]): a hybrid approach that keeps the names of all files that have a mod timestamp that is larger than the max mod time minus an offset. _org.apache.flink.streaming.api.functions.source.ContinuousFileMonitoringFunction_



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