java - Full GC real time is much more that user+sys times -

-

We are running on JBoss with the approved maximum heap size of GB on a Web Java-based applications 1.2 (total machine Physical memory is 2 GB). At some point the application stops responding (to customers) for several minutes. After some analysis, we came to know that the culprit is full GC. Here is an excerpt from a verbose GC log:

74477.402: [Full GC [PSYoungGen: 3648K-> 0K (332160K)] [PSOldGen: 778476K-> 589497K (819200K)] 782124K-> 589497K (1151360K) [PSPermGen: 102671K-> 102671K (171328K)], 646.1546860 seconds] [ Times: user = 3.84 sys = 3.72, fixed = 646.17 seconds ]

what I do not understand Now how is it possible that the real time is spent on full GC is about 11 minutes (646 seconds), while user + sys times is just 7.5 seconds. For 7.5 seconds, I spend more than 200 MB cleaning up the old generation to take more logical time. Where does all the other time go?

Thank you very much. After

The other time?

It is most likely that your application is running virtual memory threshold. Basically, your application requires more pages of virtual memory, because the physical pages to catch them available. Consequently, it is spending more time waiting for the vm pages and written on the disc.

For more information, read.

The treatment is to reduce either virtual memory usage or increase the amount of physical memory on the system. For example, you can:

  • Run less applications on the machine,
  • The Java application reduces the size of the pile, or
  • , then you Running into one virtual, allocation of virtual memory increases. (Note that reducing the JVM heap size can be a double-edged sword. If you do a lot of size of the pile, then the application will either be outoffed by my errors, many collect more garbage, or things are not able to cash effectively.)


Comments

Post a Comment

Popular posts from this blog

windows - Heroku throws SQLITE3 Read only exception -

-
After I deploy the app to Heroku, I have to run migration scripts and get this error message ... ITES \ padrino \ prophetmargin & gt; Heroku Rack AR: Rack mutated! SQLite3 :: ReadOnlyException: only one try to write database to read: CREATE TABLE "schema_migrations" ( "version" varchar (255) NOT NULL) /disk1/home/slugs/215264_925fd2c_65a3/mnt/.bundle/gems/gems/ padrino-core- is 0.9.11 / lib / padrino-core / cli / rake.rb: 9: in `init ' how can this be? I also tried to run Heroku dbpush SQLite: //db/my-db.db and that did not work Horoku sqlite3 but using postgres does not do. I'm not sure why you are receiving this error, however, as I have used sqlite3 in development and when pushing it into its travel, they do some magic which migrates to postgrads. I'm absolutely sure how Heroku does 'backwash' this database but it seems that this is happening to you because it's the SQLite db file which is obviously due to Heroku's
Read more

lex - Building a lexical Analyzer in Java -

-
I am currently learning lexical analysis in compiler design. To know how a lexical analyzer actually works, I am trying to build myself. I am planning to make it in Java The input to the lexical analyzer is a .tex file that is of the following format. \ section {script} {intro} \ section {Scope} arbitrary text \ section {relevance} uncontrolled text \ subdivision (profit) arbitrary text \ subsubsection {in real life} \ subdivision {Ingredient} \ end {document} The output of the lecture may be a table of contents with a page number in another file. 1 Introduction 1 1.1 Scope 1 1.2 Relevance 2 1.2.1 Benefits 2 1.2.1.1 Real life 2 1.2.2 loss 3 I hope that This problem is within the scope of Language Analysis Read the .exe file and check '\' and continue to check whether it is actually on search In the sectioning command is set to indicate whether or not a flag variable is the type of sectioning. I hope the above approach will work for the construction of Lexa
Read more

python - rename keys in a dictionary -

-
I want to change the names of keys in a dictionary which are ints, and I need them so that the inputs with key zero They can sort correctly. For example, my keys are like this: '1', '101', '11' and I may need them: '001', '101', '011' What is doing, but I know that there is a better way tmpDict = {} in the ADC for the old: t MpDict ['% 04d'% int (olden)] = addict [oldkey] New controlled = tmpDict You are going wrong about this if you want to draw entries on a line in a specific way, then you have to sort on the extraction. for sorted (D, key = int): print '% s:% R'% (k, d [k]) < / Div>
Read more