Hi,
For every new category created a new entry is added into
org.apache.log4j.Hierarchy.ht. And at the same time also for any
possible parent category of that new entry.
This cache is fine when you have a fairly fixed number possible
categories. That cache will grow to some size and remain that size.
In our application we have several static categories but then also
categories which consists of some subscriber identity. Possible range
here is in the order of tens of millions. Most of these subscriber
identity categories live for a fairly short time, let's say less than 10
minutes. Below is a sample output from jstat showing the number of
Logger objects going over 11M. At that point the GC starts to complain
and the JVM is starting to suffer.
Now, org.apache.log4j.Hierarchy has a "clear" method which will just
clean the ht lookup completely. Using that clear feels a bit
harsh/extreme, especially considering that we still have categories that
do live a very long time.
So, the question is if using "clear" is good practice or not? If it is
good, then fine. If not: what is good practice for keeping this ht
lookup size down to more practical levels (looking at current/live
traffic etc)?
num #instances #bytes class name
----------------------------------------------
28: 41807 1672280 org.apache.log4j.Logger
20: 88086 3523440 org.apache.log4j.Logger
15: 113835 4553400 org.apache.log4j.Logger
18: 133267 5330680 org.apache.log4j.Logger
16: 152379 6095160 org.apache.log4j.Logger
15: 173559 6942360 org.apache.log4j.Logger
11: 210480 8419200 org.apache.log4j.Logger
11: 316526 12661040 org.apache.log4j.Logger
10: 672608 26904320 org.apache.log4j.Logger
2: 892928 35717120 org.apache.log4j.Logger
...
...
...
2: 11295227 451809080 org.apache.log4j.Logger
2: 11301788 452071520 org.apache.log4j.Logger
2: 11317688 452707520 org.apache.log4j.Logger
2: 11352595 454103800 org.apache.log4j.Logger
2: 11389363 455574520 org.apache.log4j.Logger
2: 11428866 457154640 org.apache.log4j.Logger
2: 11470739 458829560 org.apache.log4j.Logger
2: 11514552 460582080 org.apache.log4j.Logger
2: 11556256 462250240 org.apache.log4j.Logger
--
__Deon_______________________________________________
TruTeq Wireless (Pty) Ltd. Tel: +27 12 667 1530
http://www.truteq.co.za Fax: +27 12 667 1531
Timezone: SAST GMT+2
Copyright&Legal: http://truteq.co.za/legal_notice.pdf
---------------------------------------------------------------------
To unsubscribe, e-mail: log4j-user-unsubscr...@logging.apache.org
For additional commands, e-mail: log4j-user-h...@logging.apache.org
