--- Cristian <[EMAIL PROTECTED]> wrote: > > I don't think your CPU L caches are going to > influence > > the issues you are seeing...not noticeably..not > with > > todays hardware. Cristian is resizing the java > heap > > to allow it to get larger than it was able before > > (default or the Tomcat default setting). In this > case > > heap being the amount of memory the java process > is > > going to be able to use for the process aside from > the > > static space which can not be controlled by the > heap > > setting being used. > > > > How much memory does your computer physically have > > Cristian? Are you also using -Xms512m? I'll wait > to > > here about your memory first before making other > > comments on that. > > > 1G of RAM and I do not set -Xms512m > swap space is hit ocasionaly but not all the time. > > > The next thing I'm going to ask deals with another > > issue we had on the list. Do you also write to > the > > HashMap from your application? Are you reading > and > > writing to this cache or your application loads > this > > cached data at start up and it is merely read from > > that point on? If you are writing to this data > you > > need to be sure to synchronize the HashMap because > if > > you don't you can get into some serious problems > with > > concurrency issues and HashMap resizing > (synchronize > > reads and writes). If you load all of the data up > > then only read from the application then > synchronizing > > the reads to the hash map won't matter (unless you > > allow reading while the loading is occuring). > > The application only caches data at startup and > after that it performs > only read operations regarding this cache. > > > The next question would be: Even if only reading > and > > you are are currently synchronizing the calls to > this > > "cached" data are the operations long? If the > > operations to a synchronized resource are very > long > > then other threads (requests in this case) will be > > delayed while trying to access the HashMap. > > I'm told that the accesses are not "long ones" ... > The designer of this > test > just accesses the HashMap. If it exists, OK they > return the value. > If not they return the name of the requested key. > > Please don't blame my lack of knowledge in this > matter, this being only > what they've told me. > I am far away (hundreds of pages of java docs) from > understanding the > functionality. > I'm only providing support on linux for tomcat > (installation with APR > etc). > They wanted to test this scenario on linux because > on windows they claim > it worked. > > However I can understand advises and put them into > practice if needed. > Also, as I said before, I am able to read some docs > that would > eventually get me to the point of solving and > understanding the problem. > > > Wade > > Thanks, > Cristian >
I don't know really. I've not seen issues with HashMap in a Linux vs. Windows scenario (might check JRE/JDK bug reports). Since your swap isn't being hit all the time I wouldn't say it would be that. I don't know really where to direct you without knowing more, because the general issues don't seem to be the cause. Does the application perform badly with only a few hits to the site? Does the application get under heavy load then stop working? Wade --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
