I have a java program which suffer from file descriptor leak.
lsof -p <PID> -nP shows a huge number of items that point to the same inode. Here is an example of the list:
java 16352 myprogram 354u unix 0xffff88042805e800 0t0 1755895875 type=STREAM
java 16352 myprogram 355u unix 0xffff88042805e800 0t0 1755895875 type=STREAM
java 16352 myprogram 356u unix 0xffff88042805e800 0t0 1755895875 type=STREAM
then i used netstat -ano, and it shows that the Inode points to an active unix domain socket. here is the list:
Active UNIX domain sockets (servers and established)
Proto RefCnt Flags Type State I-Node Path
unix 2 [ ACC ] STREAM LISTENING 1755939110 /tmp/.java_pid16352.tmp
unix 2 [ ] STREAM CONNECTED 1755871862
unix 2 [ ] STREAM CONNECTED 1755895875
here is the info provided by /proc/16352/net/unix:
Num RefCount Protocol Flags Type St Inode Path
ffff8803d0181400: 00000002 00000000 00010000 0001 01 1755939110 /tmp/.java_pid16352.tmp
ffff880426541400: 00000002 00000000 00000000 0001 03 1755871862
ffff88042805e800: 00000002 00000000 00000000 0001 03 1755895875
I tried the methods to find out the other end of the unix domain socket (https://unix.stackexchange.com/questions/16300/whos-got-the-other-end-of-this-unix-socketpair/190606#190606) , but lsof +E -aUc Xorg provided nothing; ss -xp | grep 1755895875 also provided nothing.(i don't understand what's the mean of "The sockets are identified by their inode number. Note that it's not related to the filesystem inode of the socket file." in Stéphane Chazelas's answer)
please help me finding a way to figure out:
- which thread in my java process continuously generated those unix doman socket descriptors and lead to the file descriptor leak issue.
- how can I find out the other endpoint of the unix domain socket.