When am working with 4GB RAM, the JDK is consuming all the RAM and the Processing speed is very less and unable to proceed with the work. Even for saving a simple JSF page, it's consuming 5-8 minutes.
So is it mandatory to use a RAM >4GB or is there any optimising technique so that I can continue with 4GB RAM and obtain better performance?
4 GB is enough use,you should improve memory management.
java parameters like
set JAVA_OPTS=%JAVA_OPTS% -Xms256m -Xmx512m -XX:+UseParallelGC
set JAVA_OPTS=%JAVA_OPTS% -XX:PermSize=256m -XX:MaxPermSize=512m
for JDeveloper and for tomcat . You should find some JDeveloper config file and change memory management.
4GB should be enough - the slow performance you are seeing doesn't seem to be related to memory but rather something else - try disabling the antivirus on your machine.
Some anti viruses scan JAR files as they are uploaded slowing down Java software such as JDeveloper.
Related
question, how much resources I need to run apache usergrid?
I mean hardware resources, RAM CPU
I want to deploy apache usergrid to be used as backed in our apps, the apps have a low traffic now, are custom projects to be used in small users groups (<10k)
I want to know the minimum requirements to know if it is viable for us, thanks.
From what I see of usergrid, I can think that the most hungry for resources component will be Elasticsearch, so to have a production environment that's working well, I guess you should start following ES' requirements:
At least 8 GB of RAM
At least 4 cores (the more cores you give Elasticsearch, the more love you get as it tends to works with a lot of threading, i.e. give more cores rather than more CPU processing power)
Fast HDDs should perform fine
See this article on Elasticsearch.A last thing is that depending on your system, you can tune several settings on Elasticsearch to achieve a better throughput. (For instance see https://www.elastic.co/guide/en/elasticsearch/reference/master/tune-for-indexing-speed.html)
I have deployed latest version of Usergrid i.e. 2.1, which is working smoothly in apache-cassandra-2.1.20, apache-tomcat-7.0.85, elasticsearch-1.7.6 on single node of Cassandra on Ubuntu 16.04 with 8 GB Ram and 180 GB SSD. Hope this will help you.
Background:
Windows Server 2012 R2- 64 bit
16 GB RAM
Tomcat 8
Java 8
I am running a java application on Tomcat 8. I am facing high memory usage problem. The memory usage goes up to 95% and server crashes. No problem with CPU usage.
I am setting JAVA_OPTS in tomcat\bin\catalina.bat
set "JAVA_OPTS=%JAVA_OPTS% %LOGGING_CONFIG% -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:PermSize=512m -XX:+UseParallelGC"
NOTE: XMS and XMX is set from catalina UI.
I understand, there is no PermGen concept in Java 8 so I tried below JAVA_OPTS with -XX:MaxMetaspaceSize=512m too
set "JAVA_OPTS=%JAVA_OPTS% %LOGGING_CONFIG% -XX:+CMSClassUnloadingEnabled -XX:+CMSPermGenSweepingEnabled -XX:MaxMetaspaceSize=512m -XX:+UseParallelGC"
But no luck.
Interesting thing:
The memory used by tomcat process remain around 3.5 GB but memory usage goes up to 15 GB. All the remaining processes add up to 1 GB only. I have no clue which process is consuming remaining 9-10 GB.
The system memory goes up and here is the snap.
Any thoughts?
Thanks.
The problem was with the VM we were using. There were some update processes which use to keep the VM busy.
I use this version on my dev environment : Redis-64 .
And I want to know if this version is suitable for the production environment?
If can use, then compared with under Linux, what need to be pay attention to?
Since version 3.0.3 the windows port developers abandoned the dlmalloc and began to use jemalloc as memory allocator. And the port was actually considered for production usage. The 3.0.500 build is approved for production by ms developers (see here).
And there is some kind of hell so how they bypassed the unix fork to save data to disk. Microsoft developers port call it point-in-time heap snapshot. And this is the most controversial part when used in production:
Redis under windows may need up to 3 times more memory than you need in linux version. This behavior is considered normal, because swap file in the windows can easily be up to 3 times larger than the actual amount of RAM.
I think this is acceptable only if the use Redis as LRU cache or not to save data to disk at all.
At least Redis under windows is absolutely susceptible if you Redis node use lot of memory. For example - we try to use Redis for windows (v2.8, v3.0.3, v3.0.5) on server with 512 gb of memory with 2 SSD drives (each 256 gb in raid 0) used as system disk. No any limits on windows swap file. Our test emulates our production - lots of writes and saves with RDB with utilization ~60-70% of memory. And here is was lots of hands up behaviours then this node try to save snapshots - memory consumption jumps, connection freeze during saving. Such behaviour never happens undex linux on same hardware.
Where can I change allocated memory of JDeveloper? Also Maximum and optimum memory for this IDE. My Machine has a 4GB RAM, I use SOA,BPEL frameworks in that.
Where can I change allocated memory of JDeveloper?
For JDeveloper 11.1.2.x, you can configure VM options in the JDeveloper configuration file at jdeveloper/jdev/bin/jdev.conf. For example, to set the maximum heap size to 2GB, add the following line to this file:
AddVMOption -Xmx2048M
Note that this only affects the IDE - to set memory limits for the internal Weblogic Server, you can set the USER_MEM_ARGS environment variable before launching the IDE, like
$ export USER_MEM_ARGS="-Xms256m -Xmx1024m"
Also Maximum and optimum memory for this IDE
The more, the better. There is no limit besides those imposed by the operating system or the Java virtual machine you are using (32 bit vs. 64 bit).
My Machine has a 4GB RAM, I use SOA,BPEL frameworks in that.
I really suggest that you add more memory. Use a 64 bit operating system and upgrade to at least 8 GB. You need to consider that it is not only the IDE which is consuming memory, but also the internal Weblogic Server, where you are running your application during development. The internal WLS is launched as a separate java process and also consumes a considerable amount of memory.
My original question is that, is this technically rational to check the required heap-size of my Java program on Windows 7, via VisualVM, and come to this conclusion that the program will require the same amount of heap on Linux(RedHat) as well?
I don't know how the system(OS or even CPU and RAM), affect memory management of JVM.
well, the windows is my development system with 4GB of RAM and a Core 2 Due CPU, however the
Linux is the production system with 32GB of RAM and multiple powerfull processors,
Actually, my concern is that the program on Linux might need more memory. less is ok.