About WebLogic server restart or log rotation cause server.log I node number change q

About WebLogic server reboot or log rotation causing server.log i node number change

A couple of days ago, my colleague asked me a question, that is, when the client was using Tivoli to analyze the WebLogic server log, when the server restarted, Tivoli went wrong, saying that Fileid is changed. It was suspected to be related to the Inodenumber of server log. The code for WebLogic server logging is not very well recognized because it has not been carefully read. With colleagues said, let the customer through the ls-i to confirm the corresponding inodenumber. Customer feedback said: Inodenumber did not change, crash, filename unchanged, inodenumber unchanged, Tivoli said Fileid what is it? Is there anything else in the filesystem that identifies files? I'm starting to wonder about this client, hehe. Simply, do a test yourself.

First look at the WebLogic code, log rotation, just call the File.renameto (), as follows:

Weblogic.loggin.FileStreamHandler.rotateLog ()

Logfile.renameto (Rotatedfile)

Damn it, rename's over. Inodenumber still have the same reason? Look at the JDK code again,

File.renameto ()

1　　　　　public　boolean　renameTo(File　dest)　{
2　　　　　　　　　　　　　　　　　SecurityManager　security　=　System.getSecurityManager();
3　　　　　　　　　　　　　　　　　if　(security　!=　null)　{
4　　　　　　　　　　　　　　　　　　　　　security.checkWrite(path);
5　　　　　　　　　　　　　　　　　　　　　security.checkWrite(dest.path);
6　　　　　　　　　　　　　　　　　}
7　　　　　　　　　　　　　　　　　return　fs.rename(this,dest);
8　　　　　}

This guy, or rely on the filesystem, and then look, filesystem is an abstract class, rename specific implementation must be related to the specific subclass, can only see Win32filesystem bar,

Win32filesystem.java

1　　　　　public　boolean　rename(File　f1,File　f2)　{
2　　　　　　　　　//　Keep　canonicalization　caches　in　sync　after　file　deletion
3　　　　　　　　　//　and　renaming　operations.　Could　be　more　clever　than　this
4　　　　　　　　　//　(i.e.,only　remove/update　affected　entries)　but　probably
5　　　　　　　　　//　not　worth　it　since　these　entries　expire　after　30　seconds
6　　　　　　　　　//　anyway.
7　　　　　　　　　cache.clear();
8　　　　　　　　　prefixCache.clear();
9　　　　　　　　　return　rename0(f1,f2);
10　　　　　}
11　　　　　private　native　boolean　rename0(File　f1,File　f2);

OK, now you see, RENAME0 () is a native operation, and it's related to the shared library (. dll or. so). , there is no local library code, also see what is implemented (but personally, the local implementation call should be the system function Rename:int rename (const char *old,const char *new)), can only do the implementation. wrote a small test program, as follows:

1 Package com.bea.cs.test.file
2
3 import java.io.File
4
5 public class Filetest {
6
7 Private File src = new file ("test"); 　　　　　　　　　
8
9 public static void Main (String args[])
Ten {
Filetest test = new Filetest ()
12 Test.run ();
13}
M
public void run ()
{
Rename ("Test1");
[}
'
' private b Oolean Rename (String name)
{
Boolean ret = false;
File Dest = new file (name);
ret = Src.renameto (dest);
/*
* as SRC is renamed to Dest,dest should hold the inodenumber of SRC
27 */< br> src = new File ("test");
Try
{
*/*
* As has been renamed to DEST,SRC should no T exist again
* So we should create a new src file,or it'll disappear when
EST exits.　　　　　　　　　　　　　　As a new file,src shuold get a new Inodenumber
the different from it ' s original value
36 　*/
Notoginseng if (!src.exists ())
Src.createnewfile ();
}catch (Exception e)
{
E.printstacktrace ();
"
" return ret;
"


The results of the test are as follows:

Test　Reustlslsol6%　ls　-il
total　8
6033508　drwxr-xr-x　　　3　fjin　　　　　staff　　　　　　　4096　Sep　26　23:48　com
6033514　-rw-r--r--　　　1　fjin　　　　　staff　　　　　　　　　　0　Sep　26　23:56　test
slsol6%　java　com.bea.cs.test.file.FileTest
slsol6%　ls　-il
total　8
6033508　drwxr-xr-x　　　3　fjin　　　　　staff　　　　　　　4096　Sep　26　23:48　com
6033506　-rw-r--r--　　　1　fjin　　　　　staff　　　　　　　　　　0　Sep　27　01:03　test
6033514　-rw-r--r--　　　1　fjin　　　　　staff　　　　　　　　　　0　Sep　26　23:56　test1

Now that I can doubt the client, the Tivoli error should be normal (Work as design), but what's more puzzling is: Why does Tivoli refer to Fileid instead of filename? Start by changing WebLogic code to invoke a copy-like operation instead of a rename. The result is that file does not provide a similar API, and if you do so, emptying the original file content is a problem, so forget it.