syslog: Java: Maximum number of allowed open files: 26000

[piyut_1]

Hi,

we facing the problem related to open files, with error messages in syslog belows:

Java: Number of open files: 26000

above message repeats 896 times
syslog: Java: Maximum number of allowed open files: 26000

system parameter:

# id
uid=0(root) gid=3(sys) groups=0(root),1(other),2(bin),4(adm),5(daemon),6(mail),7(lp)
# ulimit -a
time(seconds)        unlimited
file(blocks)         unlimited
data(kbytes)         2015464
stack(kbytes)        204800
memory(kbytes)       unlimited
coredump(blocks)     4194303
nofiles(descriptors) 60000
# ulimit -Ha
time(seconds)        unlimited
file(blocks)         unlimited
data(kbytes)         2015464
stack(kbytes)        204800
memory(kbytes)       unlimited
coredump(blocks)     unlimited
nofiles(descriptors) 26000
# ulimit -Sa
time(seconds)        unlimited
file(blocks)         unlimited
data(kbytes)         2015464
stack(kbytes)        204800
memory(kbytes)       unlimited
coredump(blocks)     4194303
nofiles(descriptors) 60000
# kmtune |grep files
maxfiles                60000  -  60000
maxfiles_lim            29940  Y  35000
#

is the error cause by hard limit for open files?  if yes, what parameter should be tuned ?

[Dennis Handly]

>is the error cause by hard limit for open files?

Yes, maxfiles_lim.

[piyut_1]

currently maxfiles_lim is 29940 and i cannot to add this value with error 'out of range'

# kmtune |grep files
maxfiles                60000  -  60000
maxfiles_lim            29940  Y  35000

[Dennis Handly]

>I cannot to add this value with error 'out of range'

Have you looked at maxfiles_lim(5) for all of the limitations and ordering of what parms must be in what range?

The maximum value allowed is 1048576, or 1M.  The value is further constrained in that it must be equal or greater than the soft limit, maxfiles.

[pooderbill · Accepted solution]

The maxfiles value applies to every process as it starts. However, a program can ask the OS to change the soft limit imposed by maxfiles, but the hard limit for all programs is maxfiles_lim. In your case, maxfiles_lim has been incorrectly set to much less than maxfiles.

Set maxfiles to less than maxfiles_lim, then change maxfiles_lim to 60000 (or higher if desired). Then change maxfiles to 32000 or 50000. These are just limits for programs to prevent runaway programs from grabbing far too many file handles. But Java coders can sometimes open thousands of files so increasing limits may be justified.

NOTE: maxfiles_lim is per program. The total number of open files for the entire OS is the kernel parameter nfile. For 11.31, nfile is no longer limited but for 11.23 and earler, nfile should be adjusted for the entire environment. If two programs open 10000 files, then nfile must be much larger than 20000.

[piyut_1]

Great!! many thankss..
solved with reduce maxfiles to less than maxfiles_lim.

another issue is some port used by the application cannot be telnet. From netstat -an, status port is LISTENED.

I just try to tuning the range about anon port by reduce tcp_smallest_anon_port. But the java connection growing up when i have reduced tcp_smallest_anon_port.

any idea?