[jdk8u-dev] RFR: 8237834: com/sun/jndi/ldap/LdapDnsProviderTest.java failing with LDAP response read timeout [v2]

[Takuya Kiriyama]

> Hi All,
> 
> JDK-8237834 is being backported from JDK 15 to JDK 8 to resolve instability and test failures in the JDK's LDAP DNS provider test. The issue stems from indefinite waits for LDAP responses when tests connect to unintended services on hardcoded localhost ports. The fix introduces a retry mechanism using different random ports until a "connection refused" error is received, and improves logging for better diagnostic insights, ultimately enhancing test robustness by preventing intermittent failures.
> 
> Additionally, this backport is equivalent to the fix applied in JDK 11 except with the @module annotation. This equivalence ensures consistency and demonstrates that the adjustments are robust and have been previously validated on other versions.
> 
> Would anyone review this fix?
> 
> Thank you.

Takuya Kiriyama has updated the pull request incrementally with one additional commit since the last revision:

  Update jdk/test/com/sun/jndi/ldap/LdapDnsProviderTest.java
  
  Co-authored-by: Severin Gehwolf <jerboaa at gmail.com>

-------------

Changes:
  - all: https://git.openjdk.org/jdk8u-dev/pull/756/files
  - new: https://git.openjdk.org/jdk8u-dev/pull/756/files/d3a66821..7bd671e1

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=756&range=01
 - incr: https://webrevs.openjdk.org/?repo=jdk8u-dev&pr=756&range=00-01

  Stats: 2 lines in 1 file changed: 0 ins; 1 del; 1 mod
  Patch: https://git.openjdk.org/jdk8u-dev/pull/756.diff
  Fetch: git fetch https://git.openjdk.org/jdk8u-dev.git pull/756/head:pull/756

PR: https://git.openjdk.org/jdk8u-dev/pull/756