To troubleshoot various performance issues, sometimes investigating **multiple** Java thread dumps is necessary. The method for generating these dumps can vary depending on the environment, but the commands in this article may work for many environments if the Nexus version is 3.79 and higher or `jcmd` is available.

As the correct OS user, for example `nexus`:

```auto
jcmdPath=""  # Change this if 'jcmd' is not in the PATH

pid="$(${jcmdPath:-"jcmd"} | awk '/(nexus|org.springframework.boot.loader.launch.PropertiesLauncher)/ {print $1; exit}')";
logDir="$(dirname "$(ls -l /proc/${pid}/fd | grep -E -o '\S+/nexus.log$' | head -n1)")";
filePfx="${logDir}/tasks/script-$(date +"%Y%m%d%H%M%S")";
for i in {1..5};do (top -H -b -n1 | head -n60;netstat -topen 2>/dev/null || cat /proc/net/tcp* 2>/dev/null) >> ${filePfx}999.log; ${jcmdPath:-"jcmd"} ${pid} Thread.print -l; sleep 2; done > ${filePfx}000.log

# To verify
ls -l ${filePfx}*.log
```

NOTE: the `jcmd` should be located under `$JAVA_HOME/bin/`. Or if the Nexus is using the bundled java:

```auto
$ cd ${Nexus_Installed_Dir}
$ find . -name jcmd
./nexus-3.79.0-09/jdk/temurin_17.0.13_11_mac_aarch64/jdk-17.0.13+11/Contents/Home/bin/jcmd
```

If the above commands don’t cause any errors and non-empty script-YYYYMMDDHHMMSSnnn.log files are generated, please generate the support zip **without any size limit options**.

### If no `jcmd` available

**NOTE:** this method requires `-XX:+LogVMOutput` is set and `-XX:LogFile` points to the writable jvm.log.

As the correct OS user, for example `nexus`:

```
workingDirectory="/nexus-data"   # Change this

filePfx="${workingDirectory%/}/log/tasks/script-$(date +"%Y%m%d%H%M%S")";
pid="$(head -n2 ${workingDirectory%/}/log/jvm.log | sed -n -E "s/.+ process='([^']+)'.+/\\1/p")";
[ -n "${pid}" ] && (for i in {1..5};do top -H -b -n1 | head -n60;kill -3 ${pid};netstat -topen 2>/dev/null || cat /proc/net/tcp* 2>/dev/null;sleep 2;done;sed -n -E "/^[[:space:]]*$(date +"%Y-%m-%d %H")/,$p" ${workingDirectory%/}/log/jvm.log) >> ${filePfx}909.log
```