I am working with grails framework. It takes too much time to respond a request from browser. Due to this issue i have to restart the server too many times. I will highly appreciate for your accurate answer.
You may suffer from performance issues due to insufficient memory (heap). In this case you will need increase the maximum heap size. You can use the Grails JavaMelody plugin , which integrates JavaMelody system monitoring tool into grails application, in order to tack such issues.
To increase the maximum heap size when running the application with the run-app command add the following vm option: -Xmx1024m
If running with the run-war command add the following to your BuildConfig.groovy:
grails.tomcat.jvmArgs = ['-Xmx1g']
In both cases set the maximum heap size according to your needs.
Related
I created and ran a simple SpringBoot application to accept some requests. I used jconsole to check the Heap Memory Usage and I saw this periodic increase followed by GC, I don't know the reason for the increases. Are there any Objects keep being created (because I think the instances are imported to container when the application starts)?
Spring boot has background processes which may consume your resources despite on absent requests to your app, for example jobs, etc.
Those spikes are expected and regular for any Java app based on any more less complex framework. GC algorithm depends on your jvm version, but could be overridden. The graph shows normal situation, from time to time memory consumed for some activities and after some time GC wake up and do the cleaning.
In case if you want to check what exactly objects caused memory spike you may try to use Java Flight Recorder or regular heap dump analysis using Eclipse memory analyser.
For current case Java Flight Recorder would be more convenient and suitable.
I implemented a web application to start the Tomcat service works very quickly, but spending hours and when more users are entering is getting slow (up to 15 users approx.).
Checking RAM usage statistics (20%), CPU (25%)
Server Features:
RAM 8GB
Processor i7
Windows Server 2008 64bit
Tomcat 7
MySql 5.0
Struts2
-Xms1024m
-Xmx1024m
PermGen = 1024
MaxPernGen = 1024
I do not use Web server, we publish directly on Tomcat.
Entering midnight slowness is still maintained (only 1 user online)
The solution I have is to restart the Tomcat service and response time is again excellent.
Is there anyone who has experienced this issue? Any clue would be appreciated.
Not enough details provided. Need more information :(
Use htop or top to find memory and CPU usage per process & per thread.
CPU
A constant 25% CPU usage in a 4 cores system can indicate that a single-core application/thread is running 100% CPU on the only core it is able to use.
Which application is eating the CPU ?
Memory
20% memory is ~1.6GB. It is a bit more than I expect for an idle server running only tomcat + mysql. The -Xms1024 tells tomcat to preallocate 1GB memory so that explains it.
Change tomcat settings to -Xms512 and -Xmx2048. Watch tomcat memory usage while you throw some users at it. If it keeps growing until it reaches 2GB... then freezes, that can indicate a memory leak.
Disk
Use df -h to check disk usage. A full partition can make the issues you are experiencing.
Filesystem Size Used Avail Usage% Mounted on
/cygdrive/c 149G 149G 414M 100% /
(If you just discovered in this example that my laptop is running out of space. You're doing it right :D)
Logs
Logs are awesome. Yet they have a bad habit to fill up the disk. Check logs disk usage. Are logs being written/erased/rotated properly when new users connect ? Does erasing logs fix the issue ? (copy them somewhere for future analysis before you erase them)
If not. Logs are STILL awesome. They have the good habit to help you track bugs. Check tomcat logs. You may want to set logging level to debug. What happens last when the website die ? Any useful error message ? Do user connections are still received and accepted by tomcat ?
Application
I suppose that the 25% CPU goes to tomcat (and not mysql). Tomcat doesn't fail by itself. The application running on it must be failing. Try removing the application from tomcat (you can eventually put an hello world instead). Can tomcat keep working overnight without your application ? It probably can, in which case the fault is on the application.
Enable full debug logging in your application and try to track the issue. Run it straight from eclipse in debug mode and throw users at it. Does it fail consistently in the same way ?
If yes, hit "pause" in the eclipse debugger and check what the application is doing. Look at the piece of code each thread is currently running + its call stack. Repeat that a few times. If there is a deadlock, an infinite loop, or similar, you can find it this way.
You will have found the issue by now if you are lucky. If not, you're unfortunate and it's a tricky bug that might be deep inside the application. That can get tricky to trace. Determination will lead to success. Good luck =)
For performance related issue, we need to follow the given rules:
You can equalize and emphasize the size of xms and xmx for effectiveness.
-Xms2048m
-Xmx2048m
You can also enable the PermGen to be garbage collected.
-XX:+UseConcMarkSweepGC -XX:+CMSPermGenSweepingEnabled -XX:+CMSClassUnloadingEnabled
If the page changes too frequently to make this option logical, try temporarily caching the dynamic content, so that it doesn't need to be regenerated over and over again. Any techniques you can use to cache work that's already been done instead of doing it again should be used - this is the key to achieving the best Tomcat performance.
If there any database related issue, then can follow sql query perfomance tuning
rotating the Catalina.out log file, without restarting Tomcat.
In details,There are two ways.
The first, which is more direct, is that you can rotate Catalina.out by adding a simple pipe to the log rotation tool of your choice in Catalina's startup shell script. This will look something like:
"$CATALINA_BASE"/logs/catalina.out WeaponOfChoice 2>&1 &
Simply replace "WeaponOfChoice" with your favorite log rotation tool.
The second way is less direct, but ultimately better. The best way to handle the rotation of Catalina.out is to make sure it never needs to rotate. Simply set the "swallowOutput" property to true for all Contexts in "server.xml".
This will route System.err and System.out to whatever Logging implementation you have configured, or JULI, if you haven't configured.
See more at: Tomcat Catalina Out
I experienced a very slow stock Tomcat dashboard on a clean Centos7 install and found the following cause and solution:
Slow start up times for Tomcat are often related to Java's
SecureRandom implementation. By default, it uses /dev/random as an
entropy source. This can be slow as it uses system events to gather
entropy (e.g. disk reads, key presses, etc). As the urandom manpage
states:
When the entropy pool is empty, reads from /dev/random will block until additional environmental noise is gathered.
Source: https://www.digitalocean.com/community/questions/tomcat-8-5-9-restart-is-really-slow-on-my-centos-7-2-droplet
Fix it by adding the following configuration option to your tomcat.conf or (preferred) a custom file into /tomcat/conf/conf.d/:
JAVA_OPTS="-Djava.security.egd=file:/dev/./urandom"
We encountered a similar problem, the cause was "catalina.out". It is the standard destination log file for "System.out" and "System.err". It's size kept on increasing thus slowing things down and ultimately tomcat crashed. This problem was solved by rotating "catalina.out". We were using redhat so we made a shell script to rotate "catalina.out".
Here are some links:-
Mulesoft article on catalina (also contains two methods of rotating):
Tomcat Catalina Introduction
If "catalina.out" is not the problem then try this instead:-
Mulesoft article on optimizing tomcat:
Tuning Tomcat Performance For Optimum Speed
We had a problem, which looks similar to yours. Tomcat was slow to respond, but access log showed just milliseconds for answer. The problem was streaming responses. One of our services returned real-time data that user could subscribe to. EPOLL were becoming bloated. Network requests couldn't get to the Tomcat. And whats more interesting, CPU was mostly idle (since no one could ask server to do anything) and acceptor/poller threads were sitting in WAIT, not RUNNING or IN_NATIVE.
At the time we just limited amount of such requests and everything became normal.
I am using lift framework with embedded jetty. My application is running pretty fast if I am it in development. As soon as I make a assembly of it using SBT, the performance degrades upto 20-30 times. The request which was taking 400ms, starts taking 10sec. Does lift has something to do with assembly?
Please give me some pointers to solve this problem.
Could you ensure that .jar files does not contain any test resources or configuration which can slowdown application in runtime (as example configs which turning on debug/trace priority in logger or minimize size of DB connection pool).
Also please check that start scripts for application set enough limits for heap and permgen memory size.
Following JVM options are suitable for most small and mid- sized Lift web apps:
-server -Xms256m -Xmx2048m -XX:MaxPermSize=512m -XX:+TieredCompilation
P.S. Try to find hotspots with some profiler, and then find cause of them...
The main form of my Vaadin application (running on Ubuntu server and Tomcat) takes enormous amount of time to load (more than 1 minute).
It's very simple and the web server is not under load (only a couple of users access this web server).
How can I find out why this performance problem occurs (and where is the bottleneck) ?
Vaadin by itself takes just couple of kilobytes per application. Try not to load lots of views and data in memory upfront in init. Instead, do that lazily.
I am also relatively new to Vaadin, but I can tell you this is not normal. We are running our Vaadin application on both Tomcat 6 and 7 with only a few seconds of start up time (Mac O/S). We deploy to Fedora for production.
Vaadin does take a lot of memory, and I would suggest that you check your Tomcat startup parameters to see how much is used and maybe increase it. This is the -Xmx512m switch when you run TC or any java app. I would say that 512m is really an absolute minimum for Tomcat/Vaadin for testing and 5 to 10X that or more would be used for a production environment.
Java memory defaults depend on your version of java and could be insufficient.
Smaller of 1/4th of the physical memory or 1GB. Before J2SE 5.0, the
default maximum heap size was 64MB.
Disclaimer: I am more of a programmer and have little knowledge of JBOSS.
When we deployed the system, it works properly in the test environment. However in production, since there are multiple users and a lot of data are being updated/saved, some issues occurred. Double updates are being created, some functions are not working unless the server is restartedd. I'm thinking that this may be corrected by modifying whatever session or memory parameter JBOSS has. So we could prevent restarting the server every time an error occurs.
Question: What parameter or jboss configuration should we edit to accommodate multiple users and a large number of transactions.
You need to investigate the reason for your application not behaving the way you want to. Some Points you can consider :
Log request in Jboss support.
Try increasing Java heap size. (this can be done by editing entry in standalone.conf).
Try enabling gc logs to see , if your garbage is properly collected or not.
Check for memory leakage in code.
try to analyze thread dumps to check whether some of your threads are being blocked or not.
See what if you server CPU and memory Utilization is high or not.
I'm not sure what version of JBoss you are using, but if you are wanting to increase the JVM memory you can modify the following line in the run.bat file in your bin folder:
set JAVA_OPTS=%JAVA_OPTS% -Xms128m -Xmx512m
Xms = Minimum size and Xmx is Maximum size. If you think it is due to lack of resources, you may want to increase it to something like this:
set JAVA_OPTS=%JAVA_OPTS% -Xms512m -Xmx1024m
Does everything work normally with only 1 or very few users using the system? To me it seems more like a coding issue.
Check the Heap size of JVM and set it according to Machine RAM available.
You must have performance testing done before you deploy to production. You can check the behaviour of your code in performance testing using some monitoring tool or JMX tool.
Tune the paramter like Heap size, GC alogrithm, you might want to define fixed size of young generation
Tune the thread as well.
https://developer.jboss.org/wiki/ThreadPoolConfiguration?_sscc=t