[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[
https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Colin Patrick McCabe updated HDFS-10175:
Attachment: HDFS-10175.006.patch
I posted patch 006 as an example of what I was thinking about. The idea would
be that some FS subclasses like DistributedFileSystem would override
{{FileSystem#getStorageStatistics}} to return a {{StorageStatistics}} object
with more details. In the case of {{DistributedFileSystem}} (HDFS) these would
be mostly about the number of various RPCs that were done. We would simply use
{{volatile longs}} to store this information.
> add per-operation stats to FileSystem.Statistics
>
>
> Key: HDFS-10175
> URL: https://issues.apache.org/jira/browse/HDFS-10175
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: hdfs-client
>Reporter: Ram Venkatesh
>Assignee: Mingliang Liu
> Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch,
> HDFS-10175.002.patch, HDFS-10175.003.patch, HDFS-10175.004.patch,
> HDFS-10175.005.patch, HDFS-10175.006.patch, TestStatisticsOverhead.java
>
>
> Currently FileSystem.Statistics exposes the following statistics:
> BytesRead
> BytesWritten
> ReadOps
> LargeReadOps
> WriteOps
> These are in-turn exposed as job counters by MapReduce and other frameworks.
> There is logic within DfsClient to map operations to these counters that can
> be confusing, for instance, mkdirs counts as a writeOp.
> Proposed enhancement:
> Add a statistic for each DfsClient operation including create, append,
> createSymlink, delete, exists, mkdirs, rename and expose them as new
> properties on the Statistics object. The operation-specific counters can be
> used for analyzing the load imposed by a particular job on HDFS.
> For example, we can use them to identify jobs that end up creating a large
> number of files.
> Once this information is available in the Statistics object, the app
> frameworks like MapReduce can expose them as additional counters to be
> aggregated and recorded as part of job summary.
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[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[ https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mingliang Liu updated HDFS-10175: - Attachment: HDFS-10175.005.patch > add per-operation stats to FileSystem.Statistics > > > Key: HDFS-10175 > URL: https://issues.apache.org/jira/browse/HDFS-10175 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client >Reporter: Ram Venkatesh >Assignee: Mingliang Liu > Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch, > HDFS-10175.002.patch, HDFS-10175.003.patch, HDFS-10175.004.patch, > HDFS-10175.005.patch, TestStatisticsOverhead.java > > > Currently FileSystem.Statistics exposes the following statistics: > BytesRead > BytesWritten > ReadOps > LargeReadOps > WriteOps > These are in-turn exposed as job counters by MapReduce and other frameworks. > There is logic within DfsClient to map operations to these counters that can > be confusing, for instance, mkdirs counts as a writeOp. > Proposed enhancement: > Add a statistic for each DfsClient operation including create, append, > createSymlink, delete, exists, mkdirs, rename and expose them as new > properties on the Statistics object. The operation-specific counters can be > used for analyzing the load imposed by a particular job on HDFS. > For example, we can use them to identify jobs that end up creating a large > number of files. > Once this information is available in the Statistics object, the app > frameworks like MapReduce can expose them as additional counters to be > aggregated and recorded as part of job summary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[ https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mingliang Liu updated HDFS-10175: - Attachment: HDFS-10175.004.patch > add per-operation stats to FileSystem.Statistics > > > Key: HDFS-10175 > URL: https://issues.apache.org/jira/browse/HDFS-10175 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client >Reporter: Ram Venkatesh >Assignee: Mingliang Liu > Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch, > HDFS-10175.002.patch, HDFS-10175.003.patch, HDFS-10175.004.patch, > TestStatisticsOverhead.java > > > Currently FileSystem.Statistics exposes the following statistics: > BytesRead > BytesWritten > ReadOps > LargeReadOps > WriteOps > These are in-turn exposed as job counters by MapReduce and other frameworks. > There is logic within DfsClient to map operations to these counters that can > be confusing, for instance, mkdirs counts as a writeOp. > Proposed enhancement: > Add a statistic for each DfsClient operation including create, append, > createSymlink, delete, exists, mkdirs, rename and expose them as new > properties on the Statistics object. The operation-specific counters can be > used for analyzing the load imposed by a particular job on HDFS. > For example, we can use them to identify jobs that end up creating a large > number of files. > Once this information is available in the Statistics object, the app > frameworks like MapReduce can expose them as additional counters to be > aggregated and recorded as part of job summary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[
https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Colin Patrick McCabe updated HDFS-10175:
Attachment: TestStatisticsOverhead.java
I wrote a test named {{TestStatisticsOverhead}} to quantify the overheads more
precisely. On my machine, the difference between running with this patch and
running without it is about 3MB, as quantified by {{getHeapMemoryUsage}}. This
is with 2000 threads. Since this is a per-FS overhead, some applications that
use 3 or 4 filesystem objects may experience 3x or 4x that memory overhead.
I agree that that this level of overhead is not a deal-breaker, but I would
like to understand what we are getting in exchange. Can you be a little bit
clearer about the goals for this? Right now it seems to support only HDFS.
And many of the operations are things that only HDFS will ever support, such as
{{getBytesWithFutureGenerationStamps}}. Some operations are not used at all,
such as {{COPY_FROM_LOCAL_FILE}}. It's a mishmash of high-level operations
such as copy_from_local_file, which involve multiple FSes, and very low-level
things like whether or not we called {{mkdirs}} or {{primitiveMkdir}}. Are you
planning to add this statistics support to other filesystems as well?
{{HAS_NEXT}} does not seem like a metric that users would be interested in. If
we do another {{listStatus}} RPC, we should increment {{listStatus}}.
If we are going to have these maps, we should move the existing hard-coded
statistics longs into the maps for simplicity's sake-- or at least things like
bytesReadDistanceOfOneOrTwo and bytesReadDistanceOfThreeOrFour.
> add per-operation stats to FileSystem.Statistics
>
>
> Key: HDFS-10175
> URL: https://issues.apache.org/jira/browse/HDFS-10175
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: hdfs-client
>Reporter: Ram Venkatesh
>Assignee: Mingliang Liu
> Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch,
> HDFS-10175.002.patch, HDFS-10175.003.patch, TestStatisticsOverhead.java
>
>
> Currently FileSystem.Statistics exposes the following statistics:
> BytesRead
> BytesWritten
> ReadOps
> LargeReadOps
> WriteOps
> These are in-turn exposed as job counters by MapReduce and other frameworks.
> There is logic within DfsClient to map operations to these counters that can
> be confusing, for instance, mkdirs counts as a writeOp.
> Proposed enhancement:
> Add a statistic for each DfsClient operation including create, append,
> createSymlink, delete, exists, mkdirs, rename and expose them as new
> properties on the Statistics object. The operation-specific counters can be
> used for analyzing the load imposed by a particular job on HDFS.
> For example, we can use them to identify jobs that end up creating a large
> number of files.
> Once this information is available in the Statistics object, the app
> frameworks like MapReduce can expose them as additional counters to be
> aggregated and recorded as part of job summary.
--
This message was sent by Atlassian JIRA
(v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[ https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mingliang Liu updated HDFS-10175: - Attachment: HDFS-10175.003.patch Thanks [~cmccabe] for providing comments. I agree with you about the synchronization overhead may be a concern for the client side. The v3 patch is to address this following the convention in the current statistics implementation. As the description explained, the operation-specific counters can be used for analyzing the load imposed by a particular job on HDFS. Adding the per-operation counter in Statistics object is the most straightforward and simple approach for collecting and exposing this information. > add per-operation stats to FileSystem.Statistics > > > Key: HDFS-10175 > URL: https://issues.apache.org/jira/browse/HDFS-10175 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client >Reporter: Ram Venkatesh >Assignee: Mingliang Liu > Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch, > HDFS-10175.002.patch, HDFS-10175.003.patch > > > Currently FileSystem.Statistics exposes the following statistics: > BytesRead > BytesWritten > ReadOps > LargeReadOps > WriteOps > These are in-turn exposed as job counters by MapReduce and other frameworks. > There is logic within DfsClient to map operations to these counters that can > be confusing, for instance, mkdirs counts as a writeOp. > Proposed enhancement: > Add a statistic for each DfsClient operation including create, append, > createSymlink, delete, exists, mkdirs, rename and expose them as new > properties on the Statistics object. The operation-specific counters can be > used for analyzing the load imposed by a particular job on HDFS. > For example, we can use them to identify jobs that end up creating a large > number of files. > Once this information is available in the Statistics object, the app > frameworks like MapReduce can expose them as additional counters to be > aggregated and recorded as part of job summary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[ https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mingliang Liu updated HDFS-10175: - Attachment: HDFS-10175.002.patch Hi [~cmccabe], would you kindly review the patch? I'm not sure I got the point of using thread-local variable to improve read/write performance. Thanks! > add per-operation stats to FileSystem.Statistics > > > Key: HDFS-10175 > URL: https://issues.apache.org/jira/browse/HDFS-10175 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client >Reporter: Ram Venkatesh >Assignee: Mingliang Liu > Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch, > HDFS-10175.002.patch > > > Currently FileSystem.Statistics exposes the following statistics: > BytesRead > BytesWritten > ReadOps > LargeReadOps > WriteOps > These are in-turn exposed as job counters by MapReduce and other frameworks. > There is logic within DfsClient to map operations to these counters that can > be confusing, for instance, mkdirs counts as a writeOp. > Proposed enhancement: > Add a statistic for each DfsClient operation including create, append, > createSymlink, delete, exists, mkdirs, rename and expose them as new > properties on the Statistics object. The operation-specific counters can be > used for analyzing the load imposed by a particular job on HDFS. > For example, we can use them to identify jobs that end up creating a large > number of files. > Once this information is available in the Statistics object, the app > frameworks like MapReduce can expose them as additional counters to be > aggregated and recorded as part of job summary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[ https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mingliang Liu updated HDFS-10175: - Status: Patch Available (was: In Progress) > add per-operation stats to FileSystem.Statistics > > > Key: HDFS-10175 > URL: https://issues.apache.org/jira/browse/HDFS-10175 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client >Reporter: Ram Venkatesh >Assignee: Mingliang Liu > Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch > > > Currently FileSystem.Statistics exposes the following statistics: > BytesRead > BytesWritten > ReadOps > LargeReadOps > WriteOps > These are in-turn exposed as job counters by MapReduce and other frameworks. > There is logic within DfsClient to map operations to these counters that can > be confusing, for instance, mkdirs counts as a writeOp. > Proposed enhancement: > Add a statistic for each DfsClient operation including create, append, > createSymlink, delete, exists, mkdirs, rename and expose them as new > properties on the Statistics object. The operation-specific counters can be > used for analyzing the load imposed by a particular job on HDFS. > For example, we can use them to identify jobs that end up creating a large > number of files. > Once this information is available in the Statistics object, the app > frameworks like MapReduce can expose them as additional counters to be > aggregated and recorded as part of job summary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[ https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Mingliang Liu updated HDFS-10175: - Attachment: HDFS-10175.001.patch > add per-operation stats to FileSystem.Statistics > > > Key: HDFS-10175 > URL: https://issues.apache.org/jira/browse/HDFS-10175 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client >Reporter: Ram Venkatesh >Assignee: Mingliang Liu > Attachments: HDFS-10175.000.patch, HDFS-10175.001.patch > > > Currently FileSystem.Statistics exposes the following statistics: > BytesRead > BytesWritten > ReadOps > LargeReadOps > WriteOps > These are in-turn exposed as job counters by MapReduce and other frameworks. > There is logic within DfsClient to map operations to these counters that can > be confusing, for instance, mkdirs counts as a writeOp. > Proposed enhancement: > Add a statistic for each DfsClient operation including create, append, > createSymlink, delete, exists, mkdirs, rename and expose them as new > properties on the Statistics object. The operation-specific counters can be > used for analyzing the load imposed by a particular job on HDFS. > For example, we can use them to identify jobs that end up creating a large > number of files. > Once this information is available in the Statistics object, the app > frameworks like MapReduce can expose them as additional counters to be > aggregated and recorded as part of job summary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[ https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ] Jitendra Nath Pandey updated HDFS-10175: Assignee: Mingliang Liu > add per-operation stats to FileSystem.Statistics > > > Key: HDFS-10175 > URL: https://issues.apache.org/jira/browse/HDFS-10175 > Project: Hadoop HDFS > Issue Type: Improvement > Components: hdfs-client >Reporter: Ram Venkatesh >Assignee: Mingliang Liu > > Currently FileSystem.Statistics exposes the following statistics: > BytesRead > BytesWritten > ReadOps > LargeReadOps > WriteOps > These are in-turn exposed as job counters by MapReduce and other frameworks. > There is logic within DfsClient to map operations to these counters that can > be confusing, for instance, mkdirs counts as a writeOp. > Proposed enhancement: > Add a statistic for each DfsClient operation including create, append, > createSymlink, delete, exists, mkdirs, rename and expose them as new > properties on the Statistics object. The operation-specific counters can be > used for analyzing the load imposed by a particular job on HDFS. > For example, we can use them to identify jobs that end up creating a large > number of files. > Once this information is available in the Statistics object, the app > frameworks like MapReduce can expose them as additional counters to be > aggregated and recorded as part of job summary. -- This message was sent by Atlassian JIRA (v6.3.4#6332)
[jira] [Updated] (HDFS-10175) add per-operation stats to FileSystem.Statistics
[
https://issues.apache.org/jira/browse/HDFS-10175?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Mingliang Liu updated HDFS-10175:
-
Attachment: HDFS-10175.000.patch
Thanks for creating this jira, [~venkateshrin].
The v0 patch is the initial effort according to the offline discussion with
[~jnp]. More specifically, it:
# Creates enum {{OpStatistic}} in the {{FileSystem#Statistics}} class and
supporting methods
# Updates the enum for every operation call in {{DistributedFileSystem}}
# Tries to cover S3A file system, but probably not correct
# Updates the unit test for testing this
Any comment /discussion is welcome.
> add per-operation stats to FileSystem.Statistics
>
>
> Key: HDFS-10175
> URL: https://issues.apache.org/jira/browse/HDFS-10175
> Project: Hadoop HDFS
> Issue Type: Improvement
> Components: hdfs-client
>Reporter: Ram Venkatesh
>Assignee: Mingliang Liu
> Attachments: HDFS-10175.000.patch
>
>
> Currently FileSystem.Statistics exposes the following statistics:
> BytesRead
> BytesWritten
> ReadOps
> LargeReadOps
> WriteOps
> These are in-turn exposed as job counters by MapReduce and other frameworks.
> There is logic within DfsClient to map operations to these counters that can
> be confusing, for instance, mkdirs counts as a writeOp.
> Proposed enhancement:
> Add a statistic for each DfsClient operation including create, append,
> createSymlink, delete, exists, mkdirs, rename and expose them as new
> properties on the Statistics object. The operation-specific counters can be
> used for analyzing the load imposed by a particular job on HDFS.
> For example, we can use them to identify jobs that end up creating a large
> number of files.
> Once this information is available in the Statistics object, the app
> frameworks like MapReduce can expose them as additional counters to be
> aggregated and recorded as part of job summary.
--
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