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Tsz Wo Nicholas Sze commented on HDFS-13616: -------------------------------------------- > ... I'm not sure how to apply it to stream-oriented operations like reading > and writing files, ... It seems to me that we could just return a generic result class and then we could get the input/output stream from the result. I guess this will help a lot on reading/writing a lot of small files. > ... So if we're okay with a limited set of operations initially (say, just > listing and delete), then I could look into it. Sure, it is a good start. Thank you. > Batch listing of multiple directories > ------------------------------------- > > Key: HDFS-13616 > URL: https://issues.apache.org/jira/browse/HDFS-13616 > Project: Hadoop HDFS > Issue Type: New Feature > Affects Versions: 3.2.0 > Reporter: Andrew Wang > Assignee: Andrew Wang > Priority: Major > Attachments: BenchmarkListFiles.java, HDFS-13616.001.patch, > HDFS-13616.002.patch > > > One of the dominant workloads for external metadata services is listing of > partition directories. This can end up being bottlenecked on RTT time when > partition directories contain a small number of files. This is fairly common, > since fine-grained partitioning is used for partition pruning by the query > engines. > A batched listing API that takes multiple paths amortizes the RTT cost. > Initial benchmarks show a 10-20x improvement in metadata loading performance. -- This message was sent by Atlassian JIRA (v7.6.3#76005) --------------------------------------------------------------------- To unsubscribe, e-mail: hdfs-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: hdfs-issues-h...@hadoop.apache.org