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https://issues.apache.org/jira/browse/HADOOP-16830?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=17114069#comment-17114069
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Luca Canali commented on HADOOP-16830:
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We find that IO time metrics can be quite useful for debugging, and I wanted to
check if that could make sense in the context of this JIRA.
As an example, for Apache Spark we have tested with hooking up I/O timing
metrics for S3A into Spark's monitoring system (and also for HDFS and other
Hadoop compatible filesystems).
>From the end-user point of view the result is I/O time instrumenation in a
>dashboard together with other Spark's metrics (such as CPU time and run time),
>[example|https://www.slideshare.net/databricks/performance-troubleshooting-using-apache-spark-metrics/41]
The tested implementation relied on Spark 3.0's new plugin infrastructure
[SPARK-29397|https://issues.apache.org/jira/browse/SPARK-29397] that allows to
integrate external metrics into Spark instrumentation.
Example code of [Spark's plugins to capture Hadoop IO
metrics|https://github.com/cerndb/SparkPlugins/tree/master/src/main/scala/ch/cern/experimental]
Proof of concept [implementation of some read time metrics for
S3A|https://github.com/LucaCanali/hadoop/commit/4ed077061e5826711307941dd397250e2afc47a2]
> Add public IOStatistics API; S3A to support
> -------------------------------------------
>
> Key: HADOOP-16830
> URL: https://issues.apache.org/jira/browse/HADOOP-16830
> Project: Hadoop Common
> Issue Type: Sub-task
> Components: fs, fs/s3
> Affects Versions: 3.3.0
> Reporter: Steve Loughran
> Assignee: Steve Loughran
> Priority: Major
>
> Applications like to collect the statistics which specific operations take,
> by collecting exactly those operations done during the execution of FS API
> calls by their individual worker threads, and returning these to their job
> driver
> * S3A has a statistics API for some streams, but it's a non-standard one;
> Impala &c can't use it
> * FileSystem storage statistics are public, but as they aren't cross-thread,
> they don't aggregate properly
> Proposed
> # A new IOStatistics interface to serve up statistics
> # S3A to implement
> # other stores to follow
> # Pass-through from the usual wrapper classes (FS data input/output streams)
> It's hard to think about how best to offer an API for operation context
> stats, and how to actually implement.
> ThreadLocal isn't enough because the helper threads need to update on the
> thread local value of the instigator
> My Initial PoC doesn't address that issue, but it shows what I'm thinking of
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