Useful UNIX Commands

FIND Command

Remove Certain Files in a Search/Find

 find . -name '*.log' -exec rm -fr {} \;

Search for a class file inside a jar file 

 find . -name '*.jar' -exec bash -c "echo {} && jar tvf {} | grep Name_Searching_For " \;
See if a certain process is listening on a port 

 netstat -an | grep LISTEN 

Checking open files 
Shows Files Open Related to Java or ACES 

echo /proc/`ps -ef | grep java | grep -v grep | awk '{ print $2 }'`/fd | xargs ls -1 | wc -l

Shows Files Open Related to Java or ACES 

ls /proc//fd | wc -l 
Shows All of the Processes and the Tree 

pstree -A | more



Monitoring processes 

top -u aces;        // once it comes up….press "1" to see all the cores
top -H -u aces;     // once it comes up….press "1" to see all the cores  [will show you the thread usage as opposed to the CPU usage]
mpstat -P ALL;      // shows overall CPU usage

Monitoring Performance 

/usr/bin/sar 1 20;         //  Run sar command 20 times…with 1 second between it


Monitoring Disk I/O 
Monitor Input/Output Devices 

iostat -d -x -N   

:  name of device more /etc/fstab show you the mount point to ACES directory
: number of seconds between each capture of IO
: number of times to run default forever

more /etc/fstab (file that tells you the names of 
mount points) 


df -k (will also tell you the mount points) 


iostat output 

await: avg. time servicing request (svctm) + avg. time waiting in request queue.
svctm: avg. time servicing request

await should be close to svctm, means all time spent processing io. If wait greater svctm means io requests are waiting in queue a long time and there is a PROBLEM!


Monitor IO for Each CPU 

mpstat   -P all



Java Garbage Collector Monitoring 
jstat -gc   

Options
* -gc
* -gcutil
* -gcnew
* -gccapacity

If want to monitor GC stats on actual server put following in JBoss 
startup 

-verbose:gc (print the GC logs) 
-Xloggc: (for more comprehensive GC logging) 
-XX:+PrintGCDetails (for more detailed output) 
-XX:+PrintTenuringDistribution (displays the tenuring thresholds assumed by the JVM)


Java Stack Dump of Running Process 
jstack  >