[jira] [Comment Edited] (HADOOP-11656) Classpath isolation for downstream clients
[ https://issues.apache.org/jira/browse/HADOOP-11656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=16662919#comment-16662919 ] Dagang Wei edited comment on HADOOP-11656 at 10/24/18 10:05 PM: Is there a user guide on how to use the new client for HDFS/YARN/MapReduce apps? was (Author: functicons): Is there a user guide describing how to use the new client for HDFS/YARN/MapReduce apps? > Classpath isolation for downstream clients > -- > > Key: HADOOP-11656 > URL: https://issues.apache.org/jira/browse/HADOOP-11656 > Project: Hadoop Common > Issue Type: New Feature >Reporter: Sean Busbey >Assignee: Sean Busbey >Priority: Blocker > Labels: classloading, classpath, dependencies, scripts, shell > Fix For: 3.0.0-beta1 > > Attachments: HADOOP-11656_proposal.md > > > Currently, Hadoop exposes downstream clients to a variety of third party > libraries. As our code base grows and matures we increase the set of > libraries we rely on. At the same time, as our user base grows we increase > the likelihood that some downstream project will run into a conflict while > attempting to use a different version of some library we depend on. This has > already happened with i.e. Guava several times for HBase, Accumulo, and Spark > (and I'm sure others). > While YARN-286 and MAPREDUCE-1700 provided an initial effort, they default to > off and they don't do anything to help dependency conflicts on the driver > side or for folks talking to HDFS directly. This should serve as an umbrella > for changes needed to do things thoroughly on the next major version. > We should ensure that downstream clients > 1) can depend on a client artifact for each of HDFS, YARN, and MapReduce that > doesn't pull in any third party dependencies > 2) only see our public API classes (or as close to this as feasible) when > executing user provided code, whether client side in a launcher/driver or on > the cluster in a container or within MR. > This provides us with a double benefit: users get less grief when they want > to run substantially ahead or behind the versions we need and the project is > freer to change our own dependency versions because they'll no longer be in > our compatibility promises. > Project specific task jiras to follow after I get some justifying use cases > written in the comments. -- This message was sent by Atlassian JIRA (v7.6.3#76005) - To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org
[jira] [Comment Edited] (HADOOP-11656) Classpath isolation for downstream clients
[
https://issues.apache.org/jira/browse/HADOOP-11656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=15981938#comment-15981938
]
Christopher Tubbs edited comment on HADOOP-11656 at 4/24/17 9:19 PM:
-
bq. No, this isn't possible. We're talking about client side dependencies.
Maven central is exactly where the vast majority of downstream users will get
the artifacts they need to test that things work as expected.
During testing, yes, probably true that's what most users use. However, it *is*
possible to publish both shaded and non-shaded jars to Maven Central. The
{{maven-shade-plugin}} can add a "-shaded" classifier to its artifacts and
attach them to the build rather than replace the non-shaded versions. Clients
could quite easily choose which version (shaded or non) they wish to depend on
during their own development (and runtime, if they end up using those same jars
for their runtime class path).
The shaded solution might be easier for some during development... but
ultimately, what is on the runtime class path is determined by how the client
software is packaged and configured when it is deployed, rather than what's
specified in the Hadoop POM.
was (Author: ctubbsii):
bq. No, this isn't possible. We're talking about client side dependencies.
Maven central is exactly where the vast majority of downstream users will get
the artifacts they need to test that things work as expected.
During testing, yes, probably true. However, it is possible to publish both
shaded and non-shaded jars to Maven Central. The {{maven-shade-plugin}} can add
a "-shaded" classifier to its artifacts and attach them to the build rather
than replace the non-shaded versions. Clients could quite easily choose which
version (shaded or non) they wish to depend on during their own development
(and runtime, if they end up using those same jars for their runtime class
path).
The shaded solution might be easier for some during development... but
ultimately, what is on the runtime class path is determined by how the client
software is packaged and configured when it is deployed, rather than what's
specified in the Hadoop POM.
> Classpath isolation for downstream clients
> --
>
> Key: HADOOP-11656
> URL: https://issues.apache.org/jira/browse/HADOOP-11656
> Project: Hadoop Common
> Issue Type: New Feature
>Reporter: Sean Busbey
>Assignee: Sean Busbey
>Priority: Blocker
> Labels: classloading, classpath, dependencies, scripts, shell
> Attachments: HADOOP-11656_proposal.md
>
>
> Currently, Hadoop exposes downstream clients to a variety of third party
> libraries. As our code base grows and matures we increase the set of
> libraries we rely on. At the same time, as our user base grows we increase
> the likelihood that some downstream project will run into a conflict while
> attempting to use a different version of some library we depend on. This has
> already happened with i.e. Guava several times for HBase, Accumulo, and Spark
> (and I'm sure others).
> While YARN-286 and MAPREDUCE-1700 provided an initial effort, they default to
> off and they don't do anything to help dependency conflicts on the driver
> side or for folks talking to HDFS directly. This should serve as an umbrella
> for changes needed to do things thoroughly on the next major version.
> We should ensure that downstream clients
> 1) can depend on a client artifact for each of HDFS, YARN, and MapReduce that
> doesn't pull in any third party dependencies
> 2) only see our public API classes (or as close to this as feasible) when
> executing user provided code, whether client side in a launcher/driver or on
> the cluster in a container or within MR.
> This provides us with a double benefit: users get less grief when they want
> to run substantially ahead or behind the versions we need and the project is
> freer to change our own dependency versions because they'll no longer be in
> our compatibility promises.
> Project specific task jiras to follow after I get some justifying use cases
> written in the comments.
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[jira] [Comment Edited] (HADOOP-11656) Classpath isolation for downstream clients
[ https://issues.apache.org/jira/browse/HADOOP-11656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel=15523318#comment-15523318 ] Kihwal Lee edited comment on HADOOP-11656 at 9/26/16 3:04 PM: -- [~massdos...@gmail.com], this is an umbrella jira, so it might go silent for a long time, while actual work is progressing in sub-jiras. I think there was some progress in HADOOP-13070. bq. I discussed this with Arun Murthy last year and he said this would be a really good candidate for Hadoop 3.0.0 as any fix would probably break some form of backward compatibility. Is this still on the cards for inclusion in 3.0.0? I believe this still is one of the top features that people want in 3.0.0. was (Author: kihwal): [~massdos...@gmail.com], this is an umbrella jira, so it might go silent for a long time, while actual work is progressing in sub-jiras. I think there were some progress in HADOOP-13070. bq. I discussed this with Arun Murthy last year and he said this would be a really good candidate for Hadoop 3.0.0 as any fix would probably break some form of backward compatibility. Is this still on the cards for inclusion in 3.0.0? I believe this still is one of the top features that people want in 3.0.0. > Classpath isolation for downstream clients > -- > > Key: HADOOP-11656 > URL: https://issues.apache.org/jira/browse/HADOOP-11656 > Project: Hadoop Common > Issue Type: New Feature >Reporter: Sean Busbey >Assignee: Sean Busbey > Labels: classloading, classpath, dependencies, scripts, shell > Attachments: HADOOP-11656_proposal.md > > > Currently, Hadoop exposes downstream clients to a variety of third party > libraries. As our code base grows and matures we increase the set of > libraries we rely on. At the same time, as our user base grows we increase > the likelihood that some downstream project will run into a conflict while > attempting to use a different version of some library we depend on. This has > already happened with i.e. Guava several times for HBase, Accumulo, and Spark > (and I'm sure others). > While YARN-286 and MAPREDUCE-1700 provided an initial effort, they default to > off and they don't do anything to help dependency conflicts on the driver > side or for folks talking to HDFS directly. This should serve as an umbrella > for changes needed to do things thoroughly on the next major version. > We should ensure that downstream clients > 1) can depend on a client artifact for each of HDFS, YARN, and MapReduce that > doesn't pull in any third party dependencies > 2) only see our public API classes (or as close to this as feasible) when > executing user provided code, whether client side in a launcher/driver or on > the cluster in a container or within MR. > This provides us with a double benefit: users get less grief when they want > to run substantially ahead or behind the versions we need and the project is > freer to change our own dependency versions because they'll no longer be in > our compatibility promises. > Project specific task jiras to follow after I get some justifying use cases > written in the comments. -- This message was sent by Atlassian JIRA (v6.3.4#6332) - To unsubscribe, e-mail: common-issues-unsubscr...@hadoop.apache.org For additional commands, e-mail: common-issues-h...@hadoop.apache.org
[jira] [Comment Edited] (HADOOP-11656) Classpath isolation for downstream clients
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https://issues.apache.org/jira/browse/HADOOP-11656?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanelfocusedCommentId=14349332#comment-14349332
]
Colin Patrick McCabe edited comment on HADOOP-11656 at 3/5/15 7:32 PM:
---
bq. Andrew wrote: One additional note related to this, we can spend a lot of
time right now distributing 100s of MBs of jar dependencies when launching a
YARN job. Maybe this is ameliorated by the new shared distributed cache, but
I've heard this come up quite a bit as a complaint. If we could meaningfully
slim down our client, it could lead to a nice win.
I'm frustrated that nobody responded to my earlier suggestion that we
de-duplicate jars. This would drastically reduce the size of our install, and
without rearchitecting anything.
In fact I was so frustrated that I decided to write a program to do it myself
and measure the delta. Here it is:
Before:
{code}
du -h /h
249M/h
{code}
After:
{code}
du -h /h
140M/h
{code}
Seems like deduplicating jars would be a much better project than splitting
into a client jar, if we really cared about this.
And here is the de-duplicator program I wrote (in Go):
{code}
package main
import (
path/filepath
flag
fmt
os
)
var basePathToFullPath map[string][]string = map[string][]string{ }
func visit(path string, f os.FileInfo, err error) error {
if err != nil {
panic(err)
}
if f.Mode().IsDir() {
return nil
}
base := filepath.Base(path)
bases := basePathToFullPath[base]
if bases == nil {
bases = make([]string, 0, 1)
}
bases = append(bases, path)
basePathToFullPath[base] = bases
fmt.Printf(%s - %s\n, base, path)
return nil
}
func main() {
flag.Parse()
if len(os.Args) 2 {
fmt.Printf(Usage: %s [path]\n, os.Args[0])
os.Exit(1)
}
root := os.Args[1]
err := filepath.Walk(root, visit)
if err != nil {
fmt.Printf(Error while traversing %s: %s\n, root, err.Error())
os.Exit(1)
}
for basePath, fullPaths := range basePathToFullPath {
if len(fullPaths) = 1 {
continue
}
absPath, err := filepath.Abs(fullPaths[0])
if err != nil {
fmt.Printf(failed to find abspath of %s: %s\n,
fullPaths[0], err.Error())
os.Exit(1)
}
fmt.Printf(Handling %s\n, basePath)
for i := 1; i len(fullPaths); i++ {
fmt.Printf(rm %s\n, fullPaths[i])
err = os.Remove(fullPaths[i])
if err != nil {
panic(err)
}
fmt.Printf(ln %s %s\n, absPath, fullPaths[i])
err = os.Symlink(absPath, fullPaths[i])
if err != nil {
panic(err)
}
}
}
}
{code}
The measurements I made were made against trunk (branch 3.0.0)
was (Author: cmccabe):
bq. Andrew wrote: One additional note related to this, we can spend a lot of
time right now distributing 100s of MBs of jar dependencies when launching a
YARN job. Maybe this is ameliorated by the new shared distributed cache, but
I've heard this come up quite a bit as a complaint. If we could meaningfully
slim down our client, it could lead to a nice win.
I'm frustrated that nobody responded to my earlier suggestion that we
de-duplicate jars. This would drastically reduce the size of our install, and
without rearchitecting anything.
In fact I was so frustrated that I decided to write a program to do it myself
and measure the delta. Here it is:
Before:
{code}
du -h /h
249M/h
{code}
After:
{code}
du -h /h
140M/h
{code}
Seems like deduplicating jars would be a much better project than splitting
into a client jar, if we really cared about this.
And here is the de-duplicator program I wrote:
{code}
package main
import (
path/filepath
flag
fmt
os
)
var basePathToFullPath map[string][]string = map[string][]string{ }
func visit(path string, f os.FileInfo, err error) error {
if err != nil {
panic(err)
}
if f.Mode().IsDir() {
return nil
}
base := filepath.Base(path)
bases := basePathToFullPath[base]
if bases == nil {
bases = make([]string, 0, 1)
}
bases = append(bases, path)
basePathToFullPath[base] = bases
fmt.Printf(%s - %s\n, base, path)
return nil
}
func main() {
flag.Parse()
if len(os.Args) 2 {
fmt.Printf(Usage: %s [path]\n,
