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xencommons init script improvements

PATCH New George Dunlap 4 participants 7 messages Jun 29, 2010

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George Dunlap

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#0 lore raw

PATCH 1/1 xencommons init script improvements

Rework of patches from yesterday, without the first one:
* Make xencommons more verbose, as normal init scripts are
* Wait for xenstored to start before attempting to set the domain name.
- Time out after 30 seconds
- Exit the script if the timeout fails.

If exiting is not the preferred behavior, feel free to elide the error check. :-)

author
#1 lore raw

PATCH 1/1 xencommons: Make init script more verbose

Signed-off-by George Dunlap <[email protected]>
tools/hotplug/Linux/init.d/xencommons +7 -0
diff -r 3ea84fd20b26 -r ad0f9cc72415 tools/hotplug/Linux/init.d/xencommons
@@ -42,21 +42,28 @@
 		test -z "$XENSTORED_ROOTDIR" || XENSTORED_ROOTDIR="/var/lib/xenstored"
 		rm -f "$XENSTORED_ROOTDIR"/tdb* &>/dev/null
 		test -z "$XENSTORED_TRACE" || XENSTORED_ARGS=" -T /var/log/xen/xenstored-trace.log"
+
+		echo Starting xenstored...
 		xenstored --pid-file=/var/run/xenstore.pid $XENSTORED_ARGS
+		echo Setting domain 0 name...
 		xenstore-write "/local/domain/0/name" "Domain-0"
 	fi
 
+	echo Starting xenconsoled...
 	test -z "$XENCONSOLED_TRACE" || XENCONSOLED_ARGS=" -T /var/log/xen/xenstored-trace.log"
 	xenconsoled --pid-file=$XENCONSOLED_PIDFILE $XENCONSOLED_ARGS
 	test -z "$XENBACKENDD_DEBUG" || XENBACKENDD_ARGS="-d"
 	test "`uname`" != "NetBSD" || xenbackendd $XENBACKENDD_ARGS
 }
 do_stop () {
+        echo Stopping xenconsoled
 	if read 2>/dev/null <$XENCONSOLED_PIDFILE pid; then
 		kill $pid
 		while kill -9 $pid >/dev/null 2>&1; do sleep 0.1; done
 		rm -f $XENCONSOLED_PIDFILE
 	fi
+
+	echo WARNING: Not stopping xenstored, as it cannot be restarted.
 }
 
 case "$1" in
author
#2 lore raw

PATCH 1/1 xencommons: Wait for xenstored to start before setting dom0 name

In reply to George Dunlap

On one of my boxes, the xenstore-write setting dom0's name starts before xenstored is actually ready to handle the connection properly, resulting in the name set failing. Wait for xenstored to be up and responding to reads before continuing, timing out after 30 seconds.

Signed-off-by George Dunlap <[email protected]>
tools/hotplug/Linux/init.d/xencommons +19 -1
diff -r ad0f9cc72415 -r dc49f02fc463 tools/hotplug/Linux/init.d/xencommons
@@ -37,14 +37,32 @@
 fi
 
 do_start () {
+        local time=0
+	local timeout=30
+
 	if ! `xenstore-read -s / >/dev/null 2>&1`
 	then
 		test -z "$XENSTORED_ROOTDIR" || XENSTORED_ROOTDIR="/var/lib/xenstored"
 		rm -f "$XENSTORED_ROOTDIR"/tdb* &>/dev/null
 		test -z "$XENSTORED_TRACE" || XENSTORED_ARGS=" -T /var/log/xen/xenstored-trace.log"
 
-		echo Starting xenstored...
+		echo -n Starting xenstored...
 		xenstored --pid-file=/var/run/xenstore.pid $XENSTORED_ARGS
+
+		# Wait for xenstored to actually come up, timing out after 30 seconds
+                while [ $time -lt $timeout ] && ! `xenstore-read -s / >/dev/null 2>&1` ; do
+                    echo -n .
+		    time=$(($time+1))
+                    sleep 1
+                done
+		echo
+
+		# Exit if we timed out
+		if ! [ $time -lt $timeout ] ; then
+		    echo Could not start xenstored
+		    exit 1
+		fi
+
 		echo Setting domain 0 name...
 		xenstore-write "/local/domain/0/name" "Domain-0"
 	fi
#3 lore raw

Re: [PATCH 2 of 2] xencommons: Wait for xenstored to start before setting dom0 name

Quoted 4 lines · George Dunlap

On one of my boxes, the xenstore-write setting dom0's name starts before xenstored is actually ready to handle the connection properly, resulting in the name set failing. Wait for xenstored to be up and responding to reads before continuing, timing out after 30 seconds.

Does this make the xenstored in a stub-dom case more complicated? (due to use of "-s")

Is the domain 0 name node special enough that we could just make xenstored set it itself at start of day?

Ian.

#4 lore raw

Re: [PATCH 2 of 2] xencommons: Wait for xenstored to start before setting dom0 name

In reply to George Dunlap
Quoted 17 lines · George Dunlap

On one of my boxes, the xenstore-write setting dom0's name starts before xenstored is actually ready to handle the connection properly, resulting in the name set failing. Wait for xenstored to be up and responding to reads before continuing, timing out after 30 seconds.

Signed-off-by George Dunlap <[email protected]>

diff -r ad0f9cc72415 -r dc49f02fc463 tools/hotplug/Linux/init.d/xencommons

tools/hotplug/Linux/init.d/xencommons +3 -0
@@ -37,14 +37,32 @@
 fi
 
 do_start () {
+        local time=0
+	local timeout=30
+

tools/hotplug/Linux/init.d/xencommons line 51

Quoted 10 lines
tools/hotplug/Linux/init.d/xencommons +1 -1
 	if ! `xenstore-read -s / >/dev/null 2>&1`
 	then
 		test -z "$XENSTORED_ROOTDIR" || XENSTORED_ROOTDIR="/var/lib/xenstored"
 		rm -f "$XENSTORED_ROOTDIR"/tdb* &>/dev/null
 		test -z "$XENSTORED_TRACE" || XENSTORED_ARGS=" -T /var/log/xen/xenstored-trace.log"
 
-		echo Starting xenstored...
+		echo -n Starting xenstored...
 		xenstored --pid-file=/var/run/xenstore.pid $XENSTORED_ARGS

Why isn't xenstored ready by the time the main process exits? Seems like a bug in xenstored. Does oxenstored get this right?

J

Quoted 25 lines
tools/hotplug/Linux/init.d/xencommons +15 -0
+
+		# Wait for xenstored to actually come up, timing out after 30 seconds
+                while [ $time -lt $timeout ] && ! `xenstore-read -s / >/dev/null 2>&1` ; do
+                    echo -n .
+		    time=$(($time+1))
+                    sleep 1
+                done
+		echo
+
+		# Exit if we timed out
+		if ! [ $time -lt $timeout ] ; then
+		    echo Could not start xenstored
+		    exit 1
+		fi
+
 		echo Setting domain 0 name...
 		xenstore-write "/local/domain/0/name" "Domain-0"

fi

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#5 lore raw

Re: [PATCH 2 of 2] xencommons: Wait for xenstored to start before setting dom0 name

Quoted 4 lines · Jeremy Fitzhardinge

Why isn't xenstored ready by the time the main process exits? Seems like a bug in xenstored. Does oxenstored get this right?

Looks like Bastian tried to fix this in C xenstored years ago with:

        changeset:   17296:21d9575c669e
        user:        Keir Fraser <[email protected]>
        date:        Wed Mar 26 13:21:42 2008 +0000
        files:       tools/misc/xend tools/xenstore/xenstored_core.c

description:
xenstored: Delay forking until after listening sockets are opened. Also, in startup xend script, delay further startup until xenstored initial child process has exited. This serialises xenstored startup with that of other daemons (e.g., xenconsoled).

Signed-off-by Bastian Blank <[email protected]>

But it was reverted shortly after:

        changeset:   17304:ed67f68ae2a7
        user:        Keir Fraser <[email protected]>
        date:        Thu Mar 27 09:12:09 2008 +0000
        files:       tools/misc/xend tools/xenstore/xenstored_core.c

description:
Revert 17296:21d9575c669e.

Signed-off-by Keir Fraser <[email protected]>

because it broke something. The thread at
http://lists.xensource.com/archives/html/xen-devel/2008-03/msg00758.html
has more details.

I'm not especially inclined to fix the C xenstored, lets hasten the switch to oxenstored instead.

Ian.

#6 lore raw

Re: [PATCH 2 of 2] xencommons: Wait for xenstored to start before setting dom0 name

Quoted 6 lines · Ian Campbell

because it broke something. The thread at
http://lists.xensource.com/archives/html/xen-devel/2008-03/msg00758.html
has more details.

I'm not especially inclined to fix the C xenstored, lets hasten the switch to oxenstored instead.

I'd suggest disabling C xenstored build by default and install xenstored as a symlink to oxenstored.

-- Keir