Issue 8305763 : Using underscores in the name for a URI triggers a silent
exception in the java standard library, which consumes 5% of the CPU.
Exception:
java.net.URISyntaxException: Illegal character in hostname at index N:
xyz1_abcd.com
at java.base/java.net.URI$Parser.fail(URI.java:2943)
at java.base/java.net.URI$Parser.parseHostname(URI.java:3487)
at java.base/java.net.URI$Parser.parseServer(URI.java:3329)
This exception is silent and does not produce any messages, except for ODP
profiler, there is no other evidence that it’s happening (the stack trace above
was printed after changes to Java library). The reason for this is because of
how the URI creation is implemented in the java.net.URI class. There are two
paths for creating a valid URI, and one of them goes through an exception.
We can see that if parseServer fails, there is still a way the authority gets
assigned and we don’t throw an exception from the method. This means, not being
able to parse the server is ok and the exception is silenced. In our case, the
server parsing fails because we find an illegal character, as only alphanumeric
and dash characters are allowed.
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Commit messages:
- Parsing a URI with an underscore goes through a silent exception, negatively
impacting performance
Changes: https://git.openjdk.org/jdk/pull/13430/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13430&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8305763
Stats: 16 lines in 1 file changed: 16 ins; 0 del; 0 mod
Patch: https://git.openjdk.org/jdk/pull/13430.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/13430/head:pull/13430
PR: https://git.openjdk.org/jdk/pull/13430
