Captures and analyzes Java thread dumps from XTDB to diagnose deadlocks and hangs.
npx skills add https://github.com/xtdb/xtdb --skill jstack
Please help me install this Agent Skill. Skill: jstack Source: https://github.com/xtdb/xtdb/tree/main/.claude/skills/jstack Command: npx skills add https://github.com/xtdb/xtdb --skill jstack
When an XTDB test run, node, or Gradle worker hangs, diagnosing the cause requires capturing and interpreting a Java thread dump — a file containing tens of thousands of tokens of stack traces that is impractical to read directly. This Skill guides the capture of dumps from running Gradle workers and delegates the parsing to a sub-agent so the dump stays out of the main context.
Ask the assistant to capture a thread dump from the hung Gradle worker and analyze it for deadlocks and blocked threads.
High-intent search queries and answers about installing and using this skill.
Run jps -l and grep for GradleWorkerMain to find the PID, then run jstack <PID> redirected to a file such as /tmp/jstack-<PID>.txt. If multiple workers exist, confirm which PID to analyze or capture all of them.
Delegate the dump file path to a sub-agent rather than reading it directly, since dumps are tens of thousands of tokens. Ask for deadlocks, blocked threads, lock contention, thread-state counts, pool health, and repeated stacks.
A thread dump is mostly irrelevant stack traces, and loading it consumes the main context. A cheap model handles the mechanical pattern-matching, returning only findings with thread names, lock addresses, and supporting stack excerpts.
A single dump is only one instant, so take two dumps a few seconds apart and compare them. A thread stuck in the same frame across both dumps is a much stronger signal than one sampled once.
A pool whose threads are all blocked or waiting is exhausted, and that is usually the cause rather than a symptom. Map the allocator or executor name to the XTDB subsystem, since the blockage often originates in a different subsystem.
regenrekCapture thread backtraces from live processes using LLDB and GDB.
DevelopersCoffeeRemediate CWE-833 deadlock vulnerabilities in Java code with consistent lock ordering.
adrianprecubAnalyze JVM diagnostic files to detect performance issues and generate reports.
zenobiuszetoProfile Java 21 Spring Boot services with JFR recordings and jcmd.
