Re: Apache child process not exiting after it served MaxRequestsPerChild (Apache Users)

On Tue, May 12, 2009 at 6:24 PM, Karthik kanna <kannarkk@xxxxxxxxx> wrote:

Hi,

I am using Apache 2.0.59 in AIX 5.3. Apache is running as "apache" user-id, even the parent process is also running as "apache" user-id. I am using non-standard ports like 8028/9028, so I do not require root user to run the parent process.. This is the configuration I am using in Apache 2.0.59.

StartServers 2
MaxClients 150
MinSpareThreads 25
MaxSpareThreads 75
ThreadsPerChild 25
MaxRequestsPerChild 30000

Actually what is happening - when the child process served 30000 requests, it is not killed by the parent process and the child process is running forever on the server till I manually kill the child process or restart the Apache. But parent process spawns new child process. So the number of Apache httpd process is increasing day by day on the server. The thing is, few child process gets killed by the parent process once it served 30000 requests. But few child process is not exiting.

Truss output of the child process that is not exiting:

3911841: yield()                                =
3911841: thread_waitact(400)                    = 0
1144501: __semop(1048580, 0xF1B22D58, 1)        = 0
1144501: __semop(1048580, 0xF1B22D60, 1)        = 0
1144501: _nsleep(0x202069E8, 0x20206A60)        = 1
3911841: yield()                                =
822367: kread(-802643620, 0x00000000, 0) (sleeping...)
822367: kread(-802643620, 0x00000000, 0)        = 0
3911841: yield()                                =
822367: kread(-802643620, 0x00000000, 0) (sleeping...)
822367: kread(-802643620, 0x00000000, 0)        = 0
3911841: yield()                                =
3911841: thread_waitact(400)                    = 0

Few system calls like thread_waitact(), kread(), semop() and yield() are running infinitely for the child process. Before the child process starts executing these system call infinitely, the last system call it was executing was thread_terminate_ack() after it served 30000 requests.

In the child process, one thread is in running state executing _p_nsleep() system call and another thread is in wait state, whereas all other threads are in terminated status.

(dbx) thread
thread state-k wchan state-u k-tid mode held scope function
$t1 wait 0x38882158 running 2894597 k no pro read
>$t2 run running 3674465 k no pro _p_nsleep
$t3 terminated u no pro

Since 2 threads are not terminated, I think child process is not exiting by the process process.

Have you faced this problem? Any help you provide to resolve the issue is much appreciated.

Regards,

Karthik Kanna

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