Oracle database's control file can't be gotten via FTP when the db instance is up and runing.
Issue
- We run Oracle database on our RHEL server.
SQL> select status, instance_name from v$instance;
STATUS INSTANCE_NAME
------------ ----------------
OPEN ora11gr2
SQL> sho parameter control_files
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
control_files string /opt/oracle/app/oradata/ora11g
r2/control01.ctl, /opt/oracle/
app/flash_recovery_area/ora11g
r2/control02.ctl
- When we try to get Oracle database's control file via FTP, it timeouts and fails if the database instance is up and running.
ftp> cd /tmp/work-fcntl
250 Directory successfully changed.
ftp> get file
227 Entering Passive Mode (10,64,217,75,68,122).
421 Timeout.
- It looks ftp is trying to acquire read lock with F_RDLCK and waiting with F_SETLKW.
Strace:
[...]
15:57:32.921257 open("control01.ctl", O_RDONLY|O_NONBLOCK) = 4 <0.000012>
15:57:32.921296 fcntl(4, F_SETLKW, {type=F_RDLCK, whence=SEEK_SET, start=0, len=0}) = ? ERESTARTSYS (To be restarted) <300.000031>
16:02:32.922601 --- SIGALRM (Alarm clock) @ 0 (0) ---
16:02:32.922700 alarm(1) = 0 <0.000007>
16:02:32.922732 rt_sigreturn(0x1) = -1 EINTR (Interrupted system call) <0.000006>
16:02:32.922762 alarm(0) = 1 <0.000005>
16:02:32.922795 shutdown(0, 0 /* receive */) = 0 <0.000096>
16:02:32.922919 fcntl(0, F_GETFL) = 0x2 (flags O_RDWR) <0.000006>
16:02:32.922942 fcntl(0, F_SETFL, O_RDWR|O_NONBLOCK) = 0 <0.000005>
16:02:32.922966 write(0, "421 Timeout.\r\n", 14) = 14 <0.000074>
16:02:32.923063 fcntl(0, F_GETFL) = 0x802 (flags O_RDWR|O_NONBLOCK) <0.000005>
16:02:32.923085 fcntl(0, F_SETFL, O_RDWR) = 0 <0.000005>
16:02:32.923104 shutdown(0, 2 /* send and receive */) = 0 <0.000060>
16:02:32.923196 exit_group(0) = ?
Process 22638 detached
[...]
- Why does this happen? How do we reproduce the same issue?
Environment
- Red Hat Enterprise Linux 5
- Red Hat Enterprise Linux 6
- Oracle Database
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