We have PC with Windows with 2048 RAM.
We try to use next memory settings for JBoss:
-Xms256M -Xmx768M -XX:MaxPermSize=256M
But it cannot start:
Error occurred during initialization
of VM Could not reserve enough space
for object heap Could not create the
Java virtual machine.
JBoss starts only if we change -Xmx768M to -Xmx512M.
What can be the problem?
Update:
Now we use next settings
-Xms512M -Xmx768M -XX:MaxPermSize=156M
http://javahowto.blogspot.in/2006/06/6-common-errors-in-setting-java-heap.html
The error seems to be saying that the virtual memory size of the machine is smaller than the maximum heap size we are defining via "-Xms1303m -Xmx1303m". I have changed it to "-Xms256m -Xmx512m" and it started working in my local windows box.
Interesting. What happens when you set max memory to 513M?
If that fails, it's possibly a problem I haven't seen in quite a while. An ancient COBOL compiler I used refused to work on PCs with 640K of RAM because they used a signed-number check to decide if there was enough memory.
And in that world, 640K actually had the high bit set, hence was a negative number, so the check always failed.
I find it hard to believe that this would be the case in todays world but it may be worth looking at.
If it doesn't fail at 513M, then it may just be that you're trying to allocate too much memory. It's not necessarily physical memory that matters, address space may be the issue but you should have 2G (at least) of that as well in 32bit Windows.
With your settings shown, you use 1G just for permgen and heap. Try adjusting these until it works and post the figures you have.
There are two possible causes:
JVM couldn't find 768 MiB continuous region in the address space or
total size of free area on your RAM and paging file is less than 1 GiB.
(JVM checks them using -Xmx and -XX:MaxPermSize on startup because of GC implementation)
As you could -Xmx768m -XX:MaxPermSize156m, the latter is doubtful.
If so, the problem might be resolved by freeing RAM (e.g., stopping unused services) or extending paging file.
maybe you can reboot your pc and try again. you can't allocation the memory more than your total physical memory.
-Xms256M -Xmx768M -XX:MaxPermSize=256M should only be trying to grab 512M at most on initialization plus about 100M for the JVM process itself. Do you have that much free memory on the machine? We always run jboss on machines with 4G because the DB takes up quite a bit as well.
Here's a trick you can use to find the max amount you can set. You can simply run
java -version -Xms256M -Xmx768M -XX:MaxPermSize=256M
And then increase/decrease values until you find the max the JVM will let you set.
BTW, on a 4G 32-bit windows box, we usually set -Xms768M -Xmx1300M -XX:MaxPermSize=256M
Related
I have a java process which is running on k8s.
I set Xms and Xmx to process.
java -Xms512M -Xmx1G -XX:SurvivorRatio=8 -XX:NewRatio=6 -XX:+UseConcMarkSweepGC -XX:+UseParNewGC -XX:+CMSParallelRemarkEnabled -jar automation.jar
My expectation is that pod should consume 1.5 or 2 gb memory, but it consume much more, nearly 3.5gb. its too much.
if ı run my process on a virtual machine, it consume much less memory.
When ı check memory stat for pods, ı reliase that pod allocate too much cache memory.
Rss nearly 1.5GB is OK. Because Xmx is 1gb. But why cache nearly 3GB.
is there any way to tune or control this usage ?
/app $ cat /sys/fs/cgroup/memory/memory.stat
cache 2881228800
rss 1069154304
rss_huge 446693376
mapped_file 1060864
swap 831488
pgpgin 1821674
pgpgout 966068
pgfault 467261
pgmajfault 47
inactive_anon 532504576
active_anon 536588288
inactive_file 426450944
active_file 2454777856
unevictable 0
hierarchical_memory_limit 16657932288
hierarchical_memsw_limit 9223372036854771712
total_cache 2881228800
total_rss 1069154304
total_rss_huge 446693376
total_mapped_file 1060864
total_swap 831488
total_pgpgin 1821674
total_pgpgout 966068
total_pgfault 467261
total_pgmajfault 47
total_inactive_anon 532504576
total_active_anon 536588288
total_inactive_file 426450944
total_active_file 2454777856
total_unevictable 0
A Java process may consume much more physical memory than specified in -Xmx - I explained it in this answer.
However, in your case, it's not even the memory of a Java process, but rather an OS-level page cache. Typically you don't need to care about the page cache, since it's the shared reclaimable memory: when an application wants to allocate more memory, but there is not enough immediately available free pages, the OS will likely free a part of the page cache automatically. In this sense, page cache should not be counted as "used" memory - it's more like a spare memory used by the OS for a good purpose while application does not need it.
The page cache often grows when an application does a lot of file I/O, and this is fine.
Async-profiler may help to find the exact source of growth:
run it with -e filemap:mm_filemap_add_to_page_cache
I demonstrated this approach in my presentation.
i am monitoring weblogic server using jconsole tool. i found there is no memory leak in the heap. but i see resident memory size is growing very high and it is not coming down eventhough heap comes under 1GB. I have 6GB of heap size and 12GB of RAM. single java process is holding most of the memory. I am using weblogic9 and jdk1.5.
Once the server is restarted memory is coming down and again it started growing and reaching maximum within low time span.
-xms1024m -xmx6144m
Can someone help in resolving this issue?..Thanks in advance.
I'm trying to tune an orientdb 2.1.5 embedded application, reducing at the minimum the I/O to disk.
I've read the documentation (http://orientdb.com/docs/last/Performance-Tuning.html) and used the storage.diskCache.bufferSize flag to increment the disk cache size.
Looking at htop and top (I'm on linux) I've not noticed any increment in java process's memory usage though. Even the two mbeans exposed by orient (O2QCacheMXBean and OWOWCacheMXBean) don't highlight evidence about the increment. So how can I be sure of the current disk cache size?
This is part of my java command line:
java -server -Dcom.sun.management.jmxremote -Dcom.sun.management.jmxremote.authenticate=false -Dcom.sun.management.jmxremote.ssl=false -Dcom.sun.management.jmxremote.port=9999 -Djava.rmi.server.hostname=192.168.20.154 -Dstorage.useWAL=false -Dstorage.wal.syncOnPageFlush=false -Dstorage.diskCache.bufferSize=16384 -Dtx.useLog=false -Xms4g -Xmx4g -XX:+PerfDisableSharedMem -XX:+PrintGCDetails -XX:+PrintTenuringDistribution -XX:+PrintGCTimeStamps -Xloggc:/home/nexse/local/gc.log -jar my.jar
Thanks a lot.
in Eclipse Jboss 7.1 VM arguments
My RAM 8GB
vm arguments have a this like statements ;
-server -Xms64m
-Xmx512m
-XX:MaxPermSize=1024m
how to calculate this bold numbers?
**
Caused by: java.lang.OutOfMemoryError: Java heap space
**
You are getting that error because your server used up all of its available memory (in your case, 512mb). You can increase Xmx param, which sets the maximum amount of memory your server can use.
OutOfMemoryError can happen because of insufficient memory assignment, or memory leaks (objects that java's garbage collector can't delete, despite not being needed).
There is no magic rule to calculate those params, they depend on what you are deploying to jboss, how much concurrent users, etc, etc, etc.
You can try increasing Xmx param, and check with jvisualvm the memory usage, see how it behaves..
Hi I am trying to find the limit for xms and xmx on a 64 bit 2008R2 platform.
I have limited knowledge of this area.
Can anyone tell me if there are any issues with setting xmx and xms to 18gig. I have read about issues with garbage collection. The server has 24gig.
Thanks
Sid
I am running 65536M on 2008 R2 64-bit with no issues. Machine has 32GB physical (well, it's actually a VM, so it's virtual, but what isn't?). I actually came to your question to see if going to 96GB on a 32GB VM would be an issue, other than more disk thrashing.