I'm using the Netbeans IDE to develop a Java Web Start application that will launch from the web and then use the EclipseLink JPA to access a remote MySQL database. I'm using the Swing Application Framework to manage life cycle for my app.
When I launch the application from Netbeans it takes about 7 second for my application to load, but when I use the Netbeans IDE to create a Web Start distribution package (with the JAR and JNLP files) it takes about 60 seconds to launch. Also, the "verifying application"/"downloading application" progressbar window seems to run every time I launch the app even though a copy of it has already been cached.
From the users point of view, one first sees my splash screen for 1 to 2 seconds, then the "verifying application"/"downloading application" progressbar window for 5 to 20 seconds and then nothing for a good 40 seconds before the application launches.
The app code is written such that it should show itself BEFORE the JPA starts loading the persistence unit (so I doubt that's the problem), but I thought I'd mention it just in case.
Update: Method createEntityManagerFactory Slow With Web Start
Having looked into this further, I've found that the method createEntityManagerFactory--which is necessary for EclipseLink to connect to MySQL--takes aboutn 5 seconds to execute when I run the applicaiton from Netbeans or when I remotely log in to my server to launch the JNLP there, but when I run the application via the web the same line takes 35 seconds (hugely delaying startup). Interestingly, this time gets even worse as my internet connection speed gets worse. Below is a copy of the JNLP file I'm using.
Does anyone have any idea what may be causing such a delay?
<?xml version="1.0" encoding="UTF-8" standalone="no"?>
MyApp
My App Vendor
My App Description
MyApp
I'm not sure if you solved this yet. But, I repeated your problem and fixed it. All I had to do was switch from Eclipselink to Toplink. That simple. Startups went from 1 to 2 minutes down to 5 seconds. I even traced the app and found the same hanging during the init of eclipselink.
Hope it helps.
First of all, in the Java Control Panel enable ALL logging. This will allow you to see exactly what Java WebStart is doing (but much of it doesn't make much sense unless you have access to the WebStart source).
My guess from your description is that you have one or more unreachable DNS servers in your network configuration AND you want to access a network resource that isn't available.
Related
I'm running openjdk 11.0.3 on a server. Whenever the server has been rebooted (every night): For the first initial launch of my Application, the users have to wait for 35 Seconds before the Application is even started. (Before the first System.out.println is written from main Method.) (subsequent launches are very fast though)
I have tried the following option to debug this:
-Xlog:class+load:file=classload.txt
Here are the most important finds:
...
[2.284s][info][class,load] jdk.internal.loader.URLClassPath$FileLoader source: jrt:/java.base
[5.032s][info][class,load] sun.security.rsa.RSASignature$SHA1withRSA source: jrt:/java.base
…
[5.051s][info][class,load] java.util.LinkedList$Node source: jrt:/java.base
[8.121s][info][class,load] pos.LFChangeable source: file:/C:/Users/rho/AppData/Roaming/edapp/pos.jar
…
[8.135s][info][class,load] java.io.FileNotFoundException source: jrt:/java.base
[10.584s][info][class,load] sun.reflect.misc.ReflectUtil source: jrt:/java.base
…
[11.744s][info][class,load] java.security.NoSuchAlgorithmException source: jrt:/java.base
[34.853s][info][class,load] jdk.internal.logger.DefaultLoggerFinder source: jrt:/java.base
Why is it hanging for 23 Seconds between loading java.security.NoSuchAlgorithmException and jdk.internal.logger.DefaultLoggerFinder? And what about the other seconds of slowdowns?
edit:
Based on the comments, I will clarify some.
This is a windows rdp server. Actually, it is more than one server, but the problem persists on all servers.
The Application is a standalone Application. So every morning there are problems as users who log in to start the Application, will try to start it multiple times when "nothing happens".
I have now tried restarting one of the servers quite a few times, and this is what I found:
Starting my Application with java11 after reboot takes on average 40 seconds before the first System.out.println. Then it is only 1-2 Seconds before my first JFrame shows.
Starting my Application with java8 (sun) after reboots takes on average 16 Seconds before the first System.out.println. But I then get a 25 second delay before my first JFrame shows.
Starting my Application with java11 after already started with java8 takes on average 4-6 seconds.
Your application might be suffering from the absence of a “class data-sharing (CDS) archive”. Such an archive allows much faster loading of standard classes and has been generated by default by some installers of previous versions, but OpenJDK 11 does not have an installer.
This is addressed by JEP 341:
Currently, a JDK image includes a default class list, generated at build time, in the lib directory. Users who want to take advantage of CDS, even with just the default class list provided in the JDK, must run java -Xshare:dump as an extra step. This option is documented, but many users are unaware of it.
So while this JEP is about JDK 12 doing the necessary steps automatically, it also mentions the fix for JDK 11: just run java -Xshare:dump on the command line once, to generate the archive.
Note that you can improve the startup time even further by including application classes in the CDS. See also the Class Data Sharing section of the JDK 11 documentation.
I have now tested extensively, and I am prepared to publish my results, along with the 2 different "solutions" that I made.
First, let me explain my application a bit. It is a swing enterprise-application that started it's life 13 years ago, and has been extended every since.
This application therefore is big, does a lot of different things (although most users uses only a portion of it), and has about 120 jar-files on it's classpath including all the third-party-jars.
As previously mentioned, after restart of the server it takes 35 seconds before my first login-JFrame is shown.
Solution 1:
This was my first solution, and is not a solution to the slow start, but more a solution to the user not starting multiple instances of the application.
I noticed that although my application was very slow on the first initial start, other applications were not.
A workaround was therefore to make a small standalone-application to display the splash screen, that I start like this in my program:
splashProcess = Runtime.getRuntime().exec("javaw -jar splash.jar");
Later I just kill it off with
splashProcess.destroy();
Note that if I should create a splashscreen with new JFrame() instead, it would take the usual 35 seconds before it is displayed.
Solution 2:
While testing, I found out I could simulate a restart by just deleting all the jar-files and copying them back.
In addition to reduced testing time, I found out that starting the application with just the 4-5 jar-files needed for the initial startup was very fast (although that would have lead to ClassNotFoundExceptions later),
this also ment that I could try to figure out which jar-file which led to the hang, by starting by copying all jar-files back, and then omitting one and one more.
However, I found out that it was not one jar-file that was to blame. The seconds it takes before the application start was steadily reduced a little bit each time I removed some jar-files.
So, it seems that the problem is that the first time I call new JFrame() in my application, java seems to build some sort of index or something of all classes in the classpath, although they are not used at this time.
I don't know why it does this, but this process takes quite some time with 120 jar-files on the classpath.
This led me to solution nr 2. When my application now starts, I check for an argument "startSilent".
If this is present, the only thing my application does is show a new JDialog with size 0,0 and then call System.exit(0);
I then made a script that runs my application with the "startSilent"-parameter that starts when the user logs in.
Now, if the user logs into the server and waits at least 35 seconds before starting our application, the start is now lightning fast, as the application has already started and exited once, so that the "classpath-index" or whatever it is has been built.
If the user starts the application after a shorter time, the start-time is reduced by how long the silent-script has already run.
(And the start will always be at least a fair degree faster than before, as the script starts before the desktop is ready).
So these are the results of my findings. I hope other will find them useful, and if someone can explain why what I call the "classpath-index" is created as it is, I would be welcome.
We have an (Eclipse RCP) application of 90MB with 139 self-signed jars which starts in 8s without Web Start and in 10s in an older version of Java 7. We configured Java to not use the browser proxy, i.e. deployment.proxy.type=0.
With each update of Oracle's Java startup performance drops. It takes more and more time to fully start up:
7u60/7u65/8u25: 13s (starts after 5s of web start processing)
7u75: 23s
8u31: 20s
8u40: 29s
8u51/8u60ea: 32s
What can I do to solve this issue?
From the trace/logs I can see that it is very probable that this slowdown is completely due to validating the cached jars taking much more time. Note that this question is similar but doesn't provide the following details:
Diagnosis:
When cached, the update check runs in only 0.5s (server returns "304 Not
Modified"), but even with a full download it takes only a few seconds on the gigabit network.
After the update check, for each jar XXX there is a log entry:
validating cached jar XXX.jar
When this is done, com.sun.javaws.Main is started after which the same validation seems to happen again and takes about the same amount of time, then the application starts.
The time spent in validating the cached jars seems to correspond to
the extra time required before the application starts.
The web start splash screen always shows for about 2 seconds corresponding to the update check and is then hidden. Then after almost 20 seconds the Java console finally appears and my application actually starts.
During the delay, jp2launcher.exe uses about 16% processor time on a quad core with hyperthreading (8 logical cores). So it looks like it is fully using one of the logical processors.
What I have already tried but did not make any difference:
clearing web start cache (countless times)
configure deployment.properties to disable certificate revocation check (as well as blacklist.check and validation.ocsp, validation.crl)
running offline
using the version download protocol
add to site exceptions list
check web server logs for problems. None found, update check runs in about 500ms for all 138 jars.
use another web server
checked certificate expiration date 17 feb 2016
validated my jnlp with JaNela and found no serious issues
create a deployment rule set to allow the application to run unsigned in order to speed up validation. This should be possible and looks like a promising way to solve this, but I could not get it working. See also my answer on this post.
configured Java to "do not start the console"
Detail: some weird behavior on 7u60
In 7u60 the application is started after about 5 seconds, after which the Java console APPEARS to be doing the jar validation in the background while the application is already started. HOWEVER the .log file reports that the application gets started AFTER all the validations are done. It reports this as 25 seconds and then shows the first System.out of my application which actually happened after only 5 seconds or so. It also shows the jar update check with the server taking 10 times as long as reported by the server. So I guess this is an issue with the logging framework lagging behind! Haven't seen this on 8u51.
Not an answer per se (yet), but I found that Java 8u25 when tracing is enabled, only generate a single trace file. 8u51 generates two files, one from the JVM used to update the application and other to run it. This is new (two JVM startups) and I think is related to the new setting for using native Windows sandbox capabilities. The problem is that it shouldn't have to validate the signatures again on the second JVM. The separation on two JVM instances always happen no matter if the setting for using native sandbox is disabled (the default).
I reported a regression bug, will edit the answer if I get an answer from Oracle.
Note: Java 8u31 still runs everything on one JVM but have the same doubled startup time the question stated.
I'm fighting with MySQL, Grails and Java.
I have the app Server, with Grails app running there.
I have another server with mysql db.
I have one Java app, that connects to the server to export data in csv files.
I have a lot of data (10Million of registers) in the DB, and every 15 min the Grails app is connecting to the DB, to check and save new info. Normal way to function.
My problem is that while the grails app is working, i want to execute a java app that exports a part of the information in the db. But my problem is that the process is reaaly slow, but only sometimes. I will explain:
If the Grails App is working, my Java app needs around 4 days to export all the data.The Java proccess takes around 0.3-0% of CPU.
If I turned off the Tomcat, and consequently all the connections to the DB (show processlist command on mySQL) takes around 40 minutes
to finish all the process. The Java proccess takes around 85% of
CPU.
I'm not sure about what is the problem, but i tried everything, and my problem is that i can't stop the grails app all the times that i want to export. Because of this, there is some way to give priorities to the between processes to be sure that my Java app is going to have the highest priority?
Thanks in advance for your answers,
This sounds like a database locking issue. I'd recommend getting a tool like innotop and taking a close look at what is happening in the database. In particular, I'd take a careful look at open tables, locks, and queries active when your grails app is running.
I'm trying to deploy my Java application using Java Web Start, but I've come across a problem. When running the application through my IDE (Netbeans) it's lightning fast; everything happens within seconds. However if it's launched with Web Start it's excruciatingly slow.
Any ideas why?
I'm self-signing everything and using full permissions in the JNLP.
Java Web Start applications will always launch more slowly than launching directly via the java executable. This is because Java Web Start is doing so much more than a standard java launch:
JWS accesses the network to download the JNLP (and possibly JARs, and other resources)
JWS is checking its local cache of JARs to see if it can skip downloading the JARs
JWS is potentially downloading the jars via HTTP, if the cache is empty or out of date
JWS is checking the validity of the cryptographically strong signatures of every single jar
I think most of this is an unavoidable cost for the added power of being able to launch your application via a web browser and update your application virtually "for free."
Another possibility: Is your application running with a different VM when you launch via webstart vs. when you launch with NetBeans? You can try printing:
System.getProperty("java.home")
to find out what VM is running the currently executing process.
If it's the same VM, you might also try diffing the Java system properties between the two scenarios. Try printing out all System properties:
System.getProperties().store(System.out, "");
Wireshark can be used to help diagnose Java Web Start network issues.
Sometimes the Java Console and Java Web Start Logging can be useful in diagnosing certain JWS problems. You can enable these features through the Java Control Panel:
You can enable full logging in the Java Console and see all the things that Java Web Start is printing of debug information. You can then see where the pauses happen, which may give you an indication of the problem.
My initial guess would be that you have DNS issues, especially if the pauses are very close to a multiplum of 30 seconds.
[UPDATE: I forgot to add that this 30 sec. freezing problem only happens the first time I try to load a file from the server. Subsequent loads are very quick. Maybe some strange reverse DNS lookup? I am hosting on Google's appengine.]
I started a little project recently called http://www.chartle.net which is build around an applet.
Startup time is an important factor in the user's experience of an applet. I collect statistics and am shocked that I find often very long startup times (factor 50 to 100 higher then necessary)
The applet starts in 1-3 seconds depending on the speed of your computer and connection. Still for some users it takes up to 100 sec.
I have mixed results from my own tests. Mostly it is very fast but sometimes freezes the browser for a long time and the Java console doesn't tell me why. Best guess is, that it stalls when loading a saved chart.
Please help me figuring this out - best test by opening an already saved chart (click on one of the 'create' links at http://www.chartle.net/gallery)
Cheers,
Dieter
This is generic help rather than specific for your demo (which loaded fine for me in a few attempts).
Freezing applets
In the JDK bin directory there is a very handy programme called jstack. Refresh your browser window until it crashes and then run:
jstack *process_id*
This will give you the stack trace of any frozen Java process. If Java is not a separate process then you can use the browser's process (eg for Opera).
The following few problems were/are common for me:
I reccommend you use invokeLater rather than invokeAndWait on the init method (although you can't do this if you use start/stop methods)
Opera's custom java plugin acts very poorly...
Deadlocks caused by synch blocks and invokeAndWait's
Slow applets
Possibly the browser is fetching resources from the server, unable to use the jar file?
It may be that only the old plugin causes these problems. That means basically all people running on OSX and other users with Java prior to 1.6_update_10.
So, I would really appreciate people with such setups to watch their Java console and describe the first startup behaviour.
Cheers,
Dieter