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Steve Loughran commented on HADOOP-14766: ----------------------------------------- +if you are trying to reduce risk of throttling, you may even want to look at filesize before choosing which to upload, & try to mix big files with little ones. You'd want to sort them & start the largest few off first to stop it being a bottleneck, then go for the rest. without store throttling and bandwidth limitations, the optimal scheduling would seem to be just queue the largest files for upload first & let them sort themselves out, finishing off with all the small files after. But: those small files take up lots of HTTP requests (3x HEAD & 1 PUT & 1 DELETE with depth(file) entries), & with SSE-KMS, one createKey call. Mixing them in with the larger uploads, as well as mixing paths, would appear to be less prone to throttling > Add an object store high performance dfs put command > ---------------------------------------------------- > > Key: HADOOP-14766 > URL: https://issues.apache.org/jira/browse/HADOOP-14766 > Project: Hadoop Common > Issue Type: Sub-task > Components: fs, fs/s3 > Affects Versions: 2.8.1 > Reporter: Steve Loughran > > {{hdfs put local s3a://path}} is suboptimal as it treewalks down down the > source tree then, sequentially, copies up the file through copying the file > (opened as a stream) contents to a buffer, writes that to the dest file, > repeats. > For S3A that hurts because > * it;s doing the upload inefficiently: the file can be uploaded just by > handling the pathname to the AWS xter manager > * it is doing it sequentially, when some parallelised upload would work. > * as the ordering of the files to upload is a recursive treewalk, it doesn't > spread the upload across multiple shards. > Better: > * build the list of files to upload > * upload in parallel, picking entries from the list at random and spreading > across a pool of uploaders > * upload straight from local file (copyFromLocalFile() > * track IO load (files created/second) to estimate risk of throttling. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org