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https://issues.apache.org/jira/browse/GROOVY-12640?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=18143661#comment-18143661
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ASF GitHub Bot commented on GROOVY-12640:
-----------------------------------------
paulk-asert merged PR #3224:
URL: https://github.com/apache/groovy/pull/3224
> Grape (Ivy): default grapeConfig.xml sets no connection/read timeouts, so a
> stalled download hangs @Grab forever
> ----------------------------------------------------------------------------------------------------------------
>
> Key: GROOVY-12640
> URL: https://issues.apache.org/jira/browse/GROOVY-12640
> Project: Groovy
> Issue Type: Bug
> Components: Grape
> Affects Versions: 3.0.25, 5.1.3, 6.0.0
> Reporter: Jex Jexler
> Assignee: Paul King
> Priority: Major
> Attachments: GrapeStall.groovy
>
>
> Groovy's built-in Ivy settings (`groovy/grape/ivy/defaultGrapeConfig.xml` in
> groovy-grape-ivy, `groovy/grape/defaultGrapeConfig.xml` in earlier versions)
> do not configure any timeouts. Ivy's URL handler then uses the JDK default
> for `HttpURLConnection`, i.e. no connection or read timeout. If a repository
> stops sending data in the middle of a transfer without closing the
> connection, the grab never returns.
> Because the default settings use `lockStrategy="artifact-lock-nio"`, it does
> not stay with the one stuck thread. Every other thread in the JVM (or other
> process sharing the Grape cache) that needs the same artifact waits forever
> in `FileBasedLockStrategy.acquireLock`.
> We hit this when running many concurrent grabs against Maven Central (guava
> 10.0–19.0, 100 threads, empty cache). Runs sometimes hung with all threads
> for one version stuck: one in a socket read, the rest in `acquireLock`. A
> local HTTP server that stalls responses reproduces exactly that, and adding
> an Ivy timeout constraint fixes it.
> *Reproduction*
> The attached `GrapeStall.groovy` starts a local HTTP Maven repository on
> 127.0.0.1. The repository serves the POM of `repro:stall:1.0` normally, but
> sends only half of the jar and then stalls. The script then writes a minimal
> Ivy settings file (the same `settings`/`caches`/`ibiblio` setup as the
> default config, with the ibiblio root pointing to the local server), sets
> `grape.config` and `grape.root` to a temp directory, and grabs the artifact
> from two threads.
>
> {code:java}
> groovy GrapeStall.groovy # settings as default: no timeouts
> groovy GrapeStall.groovy 5 # plus timeout-constraint, 5 s connection/read
> timeout{code}
>
> Without timeouts (Groovy 6.0.0, groovy-grape-ivy, Ivy 2.6.0, Java 21):
> {code:java}
> Groovy 6.0.0, Java 21.0.13, timeout: none
> server: stalling GET /repro/stall/1.0/stall-1.0.jar
> grab-1 still running after 30s, at:
> at java.base/sun.nio.ch.SocketDispatcher.read0(Native Method)
> ...
> at java.base/sun.net.www.MeteredStream.read(MeteredStream.java:131)
> ...
> grab-2 still running after 30s, at:
> at java.base/java.lang.Thread.sleep(Thread.java:509)
> at
> org.apache.ivy.plugins.lock.FileBasedLockStrategy.acquireLock(FileBasedLockStrategy.java:105)
> at
> org.apache.ivy.plugins.lock.ArtifactLockStrategy.lockArtifact(ArtifactLockStrategy.java:32)
> at
> org.apache.ivy.core.cache.DefaultRepositoryCacheManager.lockMetadataArtifact(DefaultRepositoryCacheManager.java:1448)
> ...
> RESULT: 2 of 2 grab threads hung
> {code}
> (They stay like that indefinitely; the script just stops looking after 30 s.)
> With a 5 s timeout constraint, the stalled download fails with `Read timed
> out (5011ms)`. The second thread then gets the lock, tries again, and also
> fails after 5 s. Both grabs end with `download failed:
> repro#stall;1.0!stall.jar`, and there are no hangs (~11 s in total).
> The results are the same with Groovy 3.0.25 and 4.0.33 (Ivy 2.5.3) and 5.1.3
> (Ivy 2.6.0).
> *Proposal*
> Add a timeout constraint to the default settings (and to
> `relaxedGrapeConfig.xml`), and
> reference it from the remote `ibiblio` resolver. Timeout constraints have
> been supported
> since Ivy 2.5.0.
>
> {code:java}
> <ivysettings>
> <settings defaultResolver="downloadGrapes"/>
> <caches lockStrategy="artifact-lock-nio"/>
> <timeout-constraints>
> <timeout-constraint name="grape" connectionTimeout="30000"
> readTimeout="60000"/>
> </timeout-constraints>
> ...
> <ibiblio name="ibiblio" m2compatible="true" timeoutConstraint="grape"/>
> ...
> </ivysettings>{code}
>
> The values are only a suggestion. The read timeout applies to each socket
> read, not to the whole transfer, so even generous values do not limit large
> downloads. They only turn "hangs forever" into a normal "download failed"
> error. Users with their own `~/.groovy/grapeConfig.xml` or `grape.config` are
> not affected, since such a file replaces the default instead of being merged
> with it. That is also the current workaround: copy the whole default config
> and add the lines above.
> The same change would apply unchanged to the 4.0.x and 5.x defaults, if a
> backport is wanted.
> (Not covered here: groovy-grape-maven uses Maven Resolver's own transport
> timeouts.)
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