How to remotely profile a web application with JProfiler? - java

I am running a web application that is deployed on remote machine server and I have the IP address and URL of this application. When I hit the URL with a browser, the application displays.
I now have to profile that web application, as I need to find out why it is running so slow.
I tried using JProfiler, have not been successful. Could someone please advise how to configure JProfiler for remote profiling?

The easiest way to profile a remote JVM on a system without a GUI is this:
Extract the JProfiler archive (not the installer) somewhere on the remote machine
In the installation directory call bin/jpenable and select the JVM you want to profile
On your local machine start JProfiler and create a new session of type "Attach to profiled JVM (local or remote)"
In the session configuration, enter the host name and the port as given by jpenable
Start the session and profile
Tip: To find a bottleneck, use sampling not instrumentation.
Update for JProfiler 10.0+
Since JProfiler 10.0, there is a remote attach feature that does not require any of the above steps, you just need SSH credentials to the remote machine.
SSH connections are made directly by JProfiler, you don't have to set up the SSH tunnel yourself. It's also possible to configure multi-hop tunnels.
JProfiler will automatically download the required agent package, upload it to the remote machine and use its command line tools to gather the information that you see in the attach dialog. The agent package is cached, so this is only done once.
Because you have to authenticate as the same user that has started the JVM that you want to profile, it is possible to switch the user for the remote attach. For example, you can sudo to the root user to attach to a service that was started as root.
All the JVMs started by the selected user are shown and you can either start a full profiling session or just take a low-overhead HPROF heap dump and open it in JProfiler.

Related

Remote Profiling in Jprofiler

I have my sample java application running on port 9010 in one of my Azure VM with an IP let say xxx.xx.xx.254. I have installed Jprofiler in another Azure VM, with IP xxx.xx.xx.159. How can i profile the application from xxx.xx.xx.159 (Both machines are Windows)?
I have tried remote profile using direct connection, but it couldn't connect. Also checked with SSH, that too failed as 'Connection timeout'
Is there any step by step process for this connection?
Solution to the problem, how to connect and profile the Remote application from my local machine using JProfiler
"Direct connection" means that you can connect to remote machine on the selected profiling port (8849 by default). This is usually not the case unless the remote machine is on a private network because firewalls will prevent the connection. Also, in that case you must have added the -agentpath VM parameter for loading the JProfiler agent to the start command of the profiled JVM. This parameter can be obtained by invoking the "Session->Integration Wizards->New Remote Integration" wizard.
With SSH connections in JProfiler, you can tunnel the connection through SSH. This will work if you have an SSH server running on the remove machine. SSH connections work for VMs where the JProfiler agent has been loaded with the -agentpath VM parameter as well as in attach mode for all JVMs that are running on the remote system.
The related documentation is available at
https://www.ej-technologies.com/resources/jprofiler/help/doc/main/profiling.html

Profiling tomcat application with VisualVM

I am trying to run visualvm under the username tomcat6 because apparently visualvm can only find applications running under its username. So by default it is only finding applications running under my username. I have been able to connect visualvm with tomcat6 through jmx but that lacks the fine granularity of instrumented profiling.
I tried the following to run visualvm under the username tomcat6 but got the following error that I don't understand.
$ sudo -u tomcat6 jvisualvm
No protocol specified
Exception in thread "main" java.awt.AWTError: Can't connect to X11 window server using ':0' as the value of the DISPLAY variable.
at sun.awt.X11GraphicsEnvironment.initDisplay(Native Method)
at sun.awt.X11GraphicsEnvironment.access$200(X11GraphicsEnvironment.java:65)
at sun.awt.X11GraphicsEnvironment$1.run(X11GraphicsEnvironment.java:115)
...
If the computer running your application is remote -- like a server -- then you can't run GUI applications without some work. It's probably going to be easier to enable remote access to VisualVM.
You can use two techniques to attach to a remote JVM: using jstatd or using JMX. I'm not sure what you think you are losing by using JMX, but evidently jstatd doesn't give you access to profiling tools, CPU monitor, etc.).
You need to configure your JVM and Tomcat to allow for remote access. That requires 3 steps:
Enable remote JMX. Turns out, there's a guide for that.
Fix the "wandering port" used for RMI. There's a guide for that, too.
(Optional) Arrange for secure remote-access to the server. The easiest way to do that would be to use ssh -Lport:localhost:port with a series of -L arguments to forward multiple ports from your workstation to your server. Map all the ports you had to configure in steps #1 and #2. If you don't do this, you'll need to have non-firewalled access to all the aforementioned ports.
Restart your JVM and connect with JVisualVM.
Update 2022-06-01
Note that the "wandering port" problem has been fixed at the JVM level, so there is no need for application (i.e. Tomcat) support for that. Item #1 for Tomcat 8.5 and later contains updated instructions making item #2 unnecessary with a recent JVM.
Unfortunately only sampling is available in remote mode so JMX will lack instrumentation tools.
Actually your approach to running visualvm under tomcat6 user is correct. You should take a look at this question on how to run X11 applications under sudo.
The easiest way to pass DISPLAY and XAUTHORITY environment variables is to use sudo -E command to preserve current user environment.
Also if you can't see your process under tomcat6 user you should check if CATALINA_TMPDIR is pointing to /tmp. Otherwise you should pass it to visualvm
jvisualvm -J-Djava.io.tmpdir="${CATALINA_TMPDIR}"
Actually there is a lot of alternatives like yourkit or jprofiler shipped with java agents which allows remote instrumentation profiling.
The easiest is to open a remote JXM port on Tomcat in order to be able to remotely (from your desktop computer) connect to your remote Tomcat (on your server) with jvisualvm.
You need to pass the following system properties to your JVM :
-Dcom.sun.management.jmxremote
-Dcom.sun.management.jmxremote.port=<whatever_port_you_want>
-Dcom.sun.management.jmxremote.ssl=false
Then open jvisualvm on your local computer (JVM version needs to be the same or newer), File -> Add Remote Host -> Enter the name on the Host. It will create an entry for this host. Right lick on this Entry -> Add JMX connection -> Enter the port -> OK
jvisualvm will then be able to access remotely to your application.
You can also secure the connection if needed by using the following system properties (you need to create the files and locate them where you want :
-Dcom.sun.management.jmxremote.password.file=jmxremote.password
-Dcom.sun.management.jmxremote.access.file=jmxremote.access
These properties needs to be added to the CATALINA_OPTS environment variable. Fr exemple :
export CATALINA_OPTS = "$CATALINA_OPTS -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.port=8888 "
More info on JMX lies here : https://docs.oracle.com/javase/8/docs/technotes/guides/management/agent.html
I tried to do something similar but I was not allowed to install JVisualVM on the server. Having JVisualVM connect to the remote machine never seemed to work correctly. I suspect firewall rules were blocking part of the the network connections.
The only way I found to remotely profile the server was via an ssh tunnel.
Set the JMX port in CATALINA_OPTS on the server
CATALINA_OPTS="$CATALINA_OPTS -Dcom.sun.management.jmxremote.port=13333 -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false; export CATALINA_OPTS
On your desktop machine open an ssh connection to the server
ssh -D 61444 username#tomcat.server.address
Add a flag to JVisualVM so that it will proxy its network connection
"C:\Program Files\Java\jdk1.7.0_79\bin\jvisualvm.exe" -J-Dnetbeans.system_socks_proxy=localhost:61444 -J-Djava.net.useSystemProxies=true
Have JVisualVM connect to the jmxport and the network traffic is tunneled via ssh.
Good luck.

Jprofiler unable to see Jboss JVM on remote machine

I am attempting to hook up JProfiler GUI on my local machine(Windows x64) to a JProfiler agent running on a remote (Windows x64). The remote machine has 2 JVMs - one a JBOSS JVM and another as a Java Application as a Windows Service via wrapper services of YAJSW. These JVMs are started Windows User Profile 1.
I pasted the JProfiler agent zip file on the remote machine and logged into it via mstsc. When I run the jpenable command in cmd (As admin) and it asks me to search for "already running JVMs" - I press 'y' but the cmd window automatically closes out. When I force jpenable to run with the PID of either of those JVMs - it complains that the JVMs cannot be seen by this user. Even using User Profile 1, JProfiler could not see the JBOSS JVM or the other JVM (with Show Services option) with the error message - 'No unprofiled JVMs found'.
My question is - if we have got JVMs on a remote machine started by 1 user, and I attempt to run the JProfiler agent (through jpenable) with user 2 , how can I have the agent see both JVMs to start up profiling so that I can hook up my local JProfiler GUI to either of these JVMs.
Much Appreciated !
You have to find the JProfiler attach helper service in the service manager and change its user account to the same user account that is used to start JProfiler. Then JProfiler should be able to show the process in jpenable if you tell it to search for services.
Update for JProfiler 10.0+:
Since JProfiler 10.0, it is possible to attach to services that are not started by the LocalSystem account. JProfiler can now attach to all services, started by admin and non-admin users.

Can visualvm connect automatically via JMX to a remote process?

I have a Java process running on a remote machine, and the process sets up some mbeans. I also have jstatd running on that machine as the same user as the Java process. (The mbeans can be set up programmatically or using -Dcom.sun.management.jmxremote... etc, this doesn't appear to make a difference).
VisualVM is able to make a jstatd connection to the process, which it discovers automatically, but this means I don't get access to mbeans or, for example, the CPU history chart. Alternatively I can create an explicit JMX connection, which gives me the usual range of useful tools, but I want for the application to be assigned a random JMX port when it starts, this config can't be static.
Is there any way to get VisualVM to auto-connect to my process via JMX? This would require it to auto-discover the JMX ports, but I would have thought jstatd could do that. Does anyone know of any plugins for visualvm to automate this?
Unfortunately there is no way to assign random JMX port to the remote application. You can start your remote application with
-Dcom.sun.management.jmxremote.port=<fixed port>
-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.authenticate=false
and VisualVM will be able to read this configuration via Jvmstat (provide by jstatd) and open JMX connection to your remote application automatically. So you need to assign fixed port(s) to your remote application(s). Once you have it, everything will work fine and VisualVM will automatically connect to your application via JMX (in fact it will combine data from both Jvmstat and JMX).

Using the Netbeans 6.5 profiler to profile a remote web app?

I'm having trouble using the Netbeans 6.5 profiler to profile the memory usage of a java web app, remotely.
I have followed the steps in the tutorial, and was able to customize a Tomcat instance to start with the profiling agents. I can also attach the Netbeans profiler to the running server: for some seconds, the profiler shows graphs with the memory usage of the server.
However, I am not able to run my deployed web app. After a few seconds, the server is shut down gracefully as if it simply had reached the bottom of its method main (hardly the expected behavior of a web server).
During these seconds, the server is not responsible, and I can't connect to a web application in it, they are simply not deployed.
I do not want to import my app into a new Netbeans project just for profiling it. It's possible to profile a remote app without access to its source, right ? After all, for a few seconds, the server was running and being profiled.
I want to profile a web application in Netbeans 6.5. What did I forget ?
You can use VisualVM tool as well. Follow the below mentioned steps.
1) Run jstatd ( jstat demon process) ( Run on your remote machine where application is running)
jstatd -p 1098 -J-Djava.security.policy=tools.policy ( specify unused port ) if tools.policy file is not specified create it as follows.
tools.policy
grant codebase "file:${java.home}/../lib/tools.jar" {
permission java.security.AllPermission;
};
2) Also specify the following properties before you start your JVM.
#JMX property
JVM_ARGS="${JVM_ARGS} -Dcom.sun.management.jmxremote=true"
JVM_ARGS="${JVM_ARGS} -Dcom.sun.management.jmxremote.port=10992"
JVM_ARGS="${JVM_ARGS} -Dcom.sun.management.jmxremote.authenticate=false"
JVM_ARGS="${JVM_ARGS} -Dcom.sun.management.jmxremote.ssl=false"
3) Start the visual VM on local machine.
a. Under remote tab add remote node.
b. Wait for couple of minutes you will see all the core applications instance will be seen under remote tab.
c. Click on remote node then select Add JMX connections specify node:port (port mentioned above in point 2.)
d. Wait for few seconds you will see JMX connection under remote node.
4) After few seconds you will see new tab appearing under remote node. Double click on the remote_node:10992 you will see the profile table on right hand side.
You can see memory , cpu , thread etc details ..
Are profiling the entire webserver or did you use the profiling filter to profile only your package?
Reducing the interaction between the profiler and the app server itself can solve it.
Check your jvm version. The version used by netbeans should be same as that in tomcat.
Use default ports. If you have changed any ports ensure they are above 1024.
Try to profile the example application in tomcat (remove all other applications). If it is running sucessfully it means there is a memory constraint.
Profiling requires huge memory. use -xms1024m -xmx1024m for tomcat.
If every thing else fail. think of switching to jdk6 and tomcat 6.
After many trials I discoverd that there are lot of limitations in jdk5 and tomcat5. switching to tomcat6 and jdk6 solved the problem for me.
Profiling with netbeans does not work jrockit, ibm jdk etc..
--kiran.kumar

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