corda/experimental/quasar-hook
Arshad Mahmood 6dd33fb8f7 Upgrade to gradle 7.6, kotlin 1.8 and jdk 17
Major changes due to JDK 17:
1. JDK17 JCE Provider now has built-in support for eddsas, corda uses
   the bouncycastle (i2p) implementation. This PR removes the conflicting
   algorithms from the built-in JCE provider.

2. JavaScript scripting has been removed from the JDK, the corda log4j config was using
   scripting to conditionally output additional diagnostic info if the MDC
   was populated. This PR has removed the scripting.

3. The artifactory plug-ins used are now deprecated, this PR has removed them
   and uses the same code as Corda 5 for publishing to artifactory.

4. Javadoc generation has been modified to use the latest dokka plug-ins.

5. Gradle 7.6 has implemented an incredibly annoying change where transitive
   dependencies are not put on the compile classpath, so that they have to be
   explicitly added as dependencies to projects.

6. Mockito has been updated, which sadly meant that quite a few source files
   have to changes to use the new (org.mockito.kotlin) package name. This makes
   this PR appear much larger than it is.

7. A number of tests have been marked as ignored to get a green, broadly they fall
   into 3 classes.

   The first is related to crypto keypair tests, it appears some logic
   in the JDK prefers to use the SunJCE implementation and we prefer to use
   bouncycastle. I believe this issue can be fixed with better test setup.

   The second group is related to our use of a method called "uncheckedCast(..)",
   the purpose of this method was to get rid of the annoying unchecked cast compiler
   warning that would otherwise exist. It looks like the Kotlin 1.9 compiler type
   inference differs and at runtime sometimes the type it infers is "Void" which causes
   an exception at runtime. The simplest solution is to use an explicit cast instead of
   unchecked cast, Corda 5 have removed unchecked cast from their codebase.

   The third class are a number of ActiveMQ tests which appear to have a memory leak somewhere.
2023-11-06 10:24:17 +00:00
..
src/main/kotlin/net/corda/quasarhook [CORDA-1879]: Ensure Node dies on unrecoverable errors. () 2018-11-12 15:56:04 +00:00
build.gradle Upgrade to gradle 7.6, kotlin 1.8 and jdk 17 2023-11-06 10:24:17 +00:00
README.md Exclude jolokia packages from Quasar instrumentation. () 2017-12-21 11:06:44 +00:00

What is this?

This is a javaagent that may be used while running applications using quasar. It hooks into quasar to track what methods are scanned, instrumented and used at runtime, and generates an exclude pattern that may be passed in to quasar to stop it from scanning classes unnecessarily.

Arguments

expand, alwaysExcluded and truncate tweak the output exclude pattern. expand is a list of packages to always expand (for example instead of generating com.* generate com.google.*,com.typesafe.* etc.), alwaysExcluded is a list of packages under which all classes are considered excluded irregardless of instrumentation, truncate is a list of packages that should not be included in the exclude pattern. Truncating net.corda means nothing should be excluded from instrumentation in Corda.

How to generate an exclude pattern for Corda

In order to generate a good exclude pattern we need to exercise the Corda code so that most classes get loaded and inspected by quasar and quasar-hook. For this we can run tests using the 'Quasar exclude pattern extraction (...)' intellij run configuration, which includes the hook. In addition we should run the tool on a bare corda.jar, as some additional classes are used when the jar is invoked directly. To do this we'll use a node in samples:

./gradlew experimental:quasar-hook:jar
./gradlew samples:irs-demo:deployNodes
cd samples/irs-demo/build/nodes/NotaryService
java -javaagent:../../../../../experimental/quasar-hook/build/libs/quasar-hook.jar=expand=com,de,org,co,io;truncate=net.corda;alwaysExcluded=com.opengamma,io.atomix,org.jolokia -jar corda.jar

Once the node is started just exit the node.

We can take the union of the two generated exclude patterns to get a final one.