Dumpling DSL tutorial

Dumpling model objects have convenient toString() implementations that mimics jstack output. Note that this output is not supposed to be compatible with any format nor read by any tool. It aims for presenting as much information as possible in a convenient way while still looking familiar to jstack users.

Central abstraction in dumpling is ThreadSet, a subset of all threads in JVM runtime. ProcessRuntime.getThreads() provides access to all threads that can be further filtered. ThreadSet.where(ProcessThread.Predicate) can narrow the set using either one of predefined predicates or Java 8 lambda expression.

runtime.getThreads().where(nameIs("MyThread"))
// or since Java 8
runtime.getThreads().where(it -> "main".equals(it.getName()))

ThreadSet also overrides groovy collection methods so Dumpling DSL and known groovy methods can by used side by side.

// Find RUNNABLE ajp threads
runtime.threads.grep { it.status.runnable }.where(nameContains(~/ajp-.*/))

Predefined queries

Predefined queries can be run against ThreadSet or whole runtime simply:

runtime.query(blockingTree().showStackTraces())

// Prior to version 2.1 it is needed to import the query class and instantiate explicitly
import com.github.olivergondza.dumpling.query.BlockingTree
runtime.query(new BlockingTree().showStackTraces())

Query transforms thread set into a result object that usually represent the outcome as in terms of known Dumpling abstractions.

Continue to Reference documentation.