On Wed, 2 Oct 2024 13:38:17 GMT, Aleksei Efimov <aefi...@openjdk.org> wrote:
>> This PR proposes the following changes to address wrong timeout computations >> in the `com.sun.jndi.dns.DnsClient`: >> - The `DnsClient` has been updated to use a monotonic high-resolution (nano) >> clock. The existing `Timeout` test has also been updated to use the nano >> clock to measure observed timeout value. >> >> - The left timeout computation has been fixed to decrease the timeout value >> during each retry attempt. A new test, `TimeoutWithEmptyDatagrams`, has been >> added to test it. >> >> - The `DnsClient.blockingReceive` has been updated: >> - to detect if any data is received >> - to avoid contention with `Selector.close()` that could be called by a >> cleaner thread >> >> - The expected timeout calculation in the `Timeout` test has been updated to >> take into account the minimum retry timeout (50ms). Additionally, the max >> allowed difference between the observed timeout and the expected one has >> been increased from 50% to 67%. Taking into account 50 ms retry timeout >> decrease the maximum allowed difference is effectively set to 61%. This >> change is expected to improve the stability of the `Timeout` test which has >> been seen to fail >> [intermittentlly](https://bugs.openjdk.org/browse/JDK-8220213). If no >> objections, I'm planning to close >> [JDK-8220213](https://bugs.openjdk.org/browse/JDK-8220213) as duplicate of >> this one. >> >> JNDI/DNS jtreg tests has been executed multiple times (500+) to check if the >> new and the modified tests are stable. No failures been observed (so far?). > > Aleksei Efimov has updated the pull request incrementally with one additional > commit since the last revision: > > Add comment suggested by Daniel That is a correct observation that if `PortUnreachableException` is thrown during first query or between retry attempts we could loose a part of needed timeout per-server, and it could be hidden by previous timeout exceptions. The lost timeout cannot be compensated for such cases. What we can do, is to improve the exception reporting: - if we have only one server - we set `PortUnreachableException` as a main exception. Even if the recoverable exceptions, like `TimeoutException`, were observed before. - if we have multiple servers we add `PortUnreachableException` as suppressed exception to an exception observed first. Pushed the exception reporting change as 5177a8856f678bd5a721a0c058ec3dfe79addfa0. ------------- PR Comment: https://git.openjdk.org/jdk/pull/20892#issuecomment-2393928511
