Re: Please help me to resolve a tail related server fault

[Liu Haifeng]

We are developing our own tailer now, but I want to find out what happened with gnu tail or oracle java.

On Feb 8, 2013, at 10:03 PM, Cryptographrix <address@hidden> wrote:

I do not know what limitations STDIN has on it in java offhand, but it sounds like this is what you are trying to do:

http://www.informit.com/guides/content.aspx?g=java&seqNum=226

On Thu, Feb 7, 2013 at 11:52 PM, Liu Haifeng <address@hidden> wrote:

Hi

I have a log transport agent written in java which creates a sub process that executing "tail -F a.log" to tail log file,and the output is piped to the main java process,thus I can read and transport log content using java.

This worked fine in the past 30 days,but now it seams the java process can't read any data. I checked java thread stack, it's blocked on Java.io.FileInputStream.readBytes.

The log file I am tailing is rotated every one hour,and the fault happened at the moment the rotating script is supposed to run.

Currently I have no idea about this fault. Here following by some status of the tail process, not more as I don't have the root privilege.

 

#cat /proc/28195/status

 

Name:   tail

State:  S (sleeping)

SleepAVG:       78%

Tgid:   28195

Pid:    28195

PPid:   28143

TracerPid:      0

Uid:    0       0       0       0

Gid:    0       0       0       0

FDSize: 256

Groups: 0 1 2 3 4 6 10

VmPeak:     3828 kB

VmSize:     3828 kB

VmLck:         0 kB

VmHWM:       524 kB

VmRSS:       524 kB

VmData:      180 kB

VmStk:        88 kB

VmExe:        36 kB

VmLib:      1468 kB

VmPTE:        36 kB

StaBrk: 198b3000 kB

Brk:    198d4000 kB

StaStk: 7fff7679c1d0 kB

Threads:        1

SigQ:   0/32768

SigPnd: 0000000000000000

ShdPnd: 0000000000000000

SigBlk: 0000000000000004

SigIgn: 0000000000000003

SigCgt: 0000000000000000

CapInh: 0000000000000000

CapPrm: 00000000fffffeff

CapEff: 00000000fffffeff

Cpus_allowed:  00000000,00000000,00000000,00000000,00000000,00000000,ffffffff,ffffffff

Mems_allowed:   00000000,00000001

 

#cat /proc/28195/stat

28195 (tail) S 28143 28138 27881 0 -14202496 141 0 1 0 10328 53939 0 0 18 0 1 0 214643641 3919872 131 18446744073709551615 1 1 0 0 0 0 4 3 0 18446744073709551615 0 0 17 2 0 0 1

 

#yum list|grep coreutils

coreutils.x86_64                           5.97-34.el5_8.1             installed

policycoreutils.x86_64                     1.33.12-14.8.el5            installed

policycoreutils-gui.x86_64                 1.33.12-14.8.el5            base

policycoreutils-newrole.x86_64             1.33.12-14.8.el5            base