Analyzer java-lock-contention
Name
java-lock-contention - Java Lock and Park Wait Flame Graph
This analyzer shows which Java call paths spend time waiting for a monitor or a park. It covers common waits caused by synchronized blocks/methods and LockSupport.park. Each flame graph path represents a Java call path that was waiting. By default, the width is total wait time; metric=calls changes it to the number of waits. The Linux futex is only the JVM’s implementation detail used to detect the wait.
Resource Category
off-CPU.
Application Type & Technical Stack
- Java
Command Line Syntax
The analyzer can be invoked directly on the command-line via the orxray
utility from the openresty-xray-cli software package.
Alternatively, the analyzer can also be invoked manually or automatically on the web console UI of OpenResty XRay (like on the Advanced web page).
# PID is the target process PID.
orxray analyzer run java-lock-contention -p PID
# trace a shell command directly
orxray analyzer run java-lock-contention -c SHELL_CMD
# PGID is the process group ID or any process's PID within the target process
# group.
orxray analyzer run java-lock-contention -p -PGID
# trace any processes started from the specified executable path.
orxray analyzer run java-lock-contention --exe /path/to/exe/file
Tracing Multiple Processes
Supported.
Output Formats
- Flame Graphs
Author
The OpenResty Inc. Team.
Copyright
Copyright (C) by OpenResty Inc. All rights reserved.