Re: [Xen-devel] [patch]Make xend to take care of dead qemu-dm process

[shawn <xiaowei.hu@xxxxxxxxxx>]

Hi Kan，

Thanks for your comment.

Correctted that,and some other mistakes.

Please review this patch again.

thanks
xiaowei



--- tools/python/xen/xend/server/SrvServer.py.org       2008-05-21
13:53:08.000000000 +0800
+++ tools/python/xen/xend/server/SrvServer.py   2008-05-21
15:28:09.000000000 +0800
@@ -44,6 +44,7 @@
 import re
 import time
 import signal
+import os
 from threading import Thread
 
 from xen.web.httpserver import HttpServer, UnixHttpServer
@@ -148,14 +149,26 @@
 
             # Reaching this point means we can auto start domains
             try:
-                xenddomain().autostart_domains()
+                dom = xenddomain()
+                dom.autostart_domains()
             except Exception, e:
                 log.exception("Failed while autostarting domains")
 
             # loop to keep main thread alive until it receives a
SIGTERM
             self.running = True
             while self.running:
-                time.sleep(100000000)
+                # loop to destroy those hvm domain that whoes DM has
dead unexpectedly.
+                for item in dom.domains.values():
+                    if item.info.is_hvm():
+                        device_model_pid =
item.gatherDom(('image/device-model-pid', str))
+                        dm_stat_cmd = "ps -o stat --no-headers
-p"+device_model_pid
+                        dm_stat =
os.popen(dm_stat_cmd).readline().rstrip()
+                        if dm_stat == 'Z':
+                            log.warn("Devices Model for domain " +
str(item.domid) + "was killed unexpectedly")
+                            item.destroy()
+                        else:
+                            continue
+                time.sleep(30)
                 
             if self.reloadingConfig:
                 log.info("Restarting all XML-RPC and Xen-API
servers...")





On Wed, 2008-05-21 at 16:21 +0900, Masaki Kanno wrote:
> Hi Xiaowei,
> 
> Nonessential comment.
> 
> Your patch includes both tab-indent and space-indent.
> Could you change tab-indent to space-indent?
> 
> Best regards,
>  Kan
> 
> Wed, 21 May 2008 14:33:05 +0800, shawn wrote:
> 
> >Hi all,
> >
> >There is a problem in Xen now,When fatal error happened on VM like
> >qemu-dm process died, xend should take care of it. Don't leave it as
> >defunct process (zombie process). 
> >Because of mis-configuration or some other reason, qemu-dm process would
> >die. 
> >
> >For now, xend haven't taken care of this dead process and it remains as
> >defunct process, and xm list shows VM status assigned to the process as 
> >vserv1134             5  6144     1     ------      0.0 
> >
> >This patch fix xend as when fatal error happened (e.g. qemu-dm process
> >was killed) 
> >log  error meesge then destroy that domain and clean up the process (no
> >zombies)
> >
> >This is caused by the xend daemon, xend forks a process and run the
> >qemu-dm  program, when qemu-dm was killed directly ,xend doesn't have a
> >chance to call 
> >the wait() function to collect this zombie child(qemu-dm is executed by
> >a thread).For the xend doesn't have any idea of the qemu-dm child is
> >alive or being killed. 
> >
> >For the above reason,added some code in xend to check those hvm DM
> >status each 30 seconds. 
> >
> >Have made a patch based on the open source xen3.2.1 source code. 
> >
> >Please review this patch.
> >
> >Thanks.
> >Xiaowei
> >
> >--- xen-3.2.1/tools/python/xen/xend/server/SrvServer.py.org  2008-05-21
> >13:53:08.000000000 +0800
> >+++ xen-3.2.1/tools/python/xen/xend/server/SrvServer.py      2008-05-21
> >13:58:56.000000000 +0800
> >@@ -44,6 +44,7 @@
> > import re
> > import time
> > import signal
> >+import os
> > from threading import Thread
> > 
> > from xen.web.httpserver import HttpServer, UnixHttpServer
> >@@ -148,14 +149,28 @@
> > 
> >             # Reaching this point means we can auto start domains
> >             try:
> >-                xenddomain().autostart_domains()
> >+                dom = xenddomain()
> >+            dom.autostart_domains()
> >             except Exception, e:
> >                 log.exception("Failed while autostarting domains")
> > 
> >             # loop to keep main thread alive until it receives a
> >SIGTERM
> >             self.running = True
> >             while self.running:
> >-                time.sleep(100000000)
> >+            # loop to destroy those hvm domain that whoes DM has dead
> >unexpectedly.
> >+            for item in dom.domains.values():
> >+                    if item.info.is_hvm():
> >+                        device_model_pid =
> >item.gatherDom(('image/device-model-pid', str))
> >+                    dm_stat_cmd = "ps -o stat --no-headers -p"+
> device_model_pid
> >+                    dm_stat = os.popen(dm_stat_cmd).readline().rstrip()
> >+                    log.info("status of the command is:" + dm_stat + "end 
> of output")
> >+                    if dm_stat == 'Z':
> >+                        log.info("status of the command is:" + dm_stat + 
> "end of
> >output")
> >+                        log.warn("Devices Model for " + str(item) + "was 
> killed
> >unexpectedly")
> >+                        item.destroy()
> >+                    else:
> >+                        continue
> >+                time.sleep(30)
> >                 
> >             if self.reloadingConfig:
> >                 log.info("Restarting all XML-RPC and Xen-API
> >servers...")
> >
> >
> >_______________________________________________
> >Xen-devel mailing list
> >Xen-devel@xxxxxxxxxxxxxxxxxxx
> >http://lists.xensource.com/xen-devel
> 
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel


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