Re: Ceph slow request & unstable issue

2013-01-16 Thread Andrey Korolyov
On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  wrote:
> Hi list,
> We are suffering from OSD or OS down when there is continuing high 
> pressure on the Ceph rack.
> Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in each nodes 
> with 20 * spindles + 4* SSDs as journal.(120 spindles in total)
> We create a lots of RBD volumes (say 240),mounting to 16 different 
> client machines ( 15 RBD Volumes/ client) and running DD concurrently on top 
> of each RBD.
>
> The issues are:
> 1. Slow requests
>   From the list-archive it seems solved in 0.56.1 but we still notice such 
> warning
> 2. OSD Down or even host down
> Like the message below.Seems some OSD has been blocking there for quite a 
> long time.
>
> Suggestions are highly appreciate.Thanks
>   
>   
> Xiaoxi
>
> _
>
> Bad news:
>
> I have  back all my Ceph machine’s OS to kernel  3.2.0-23, which Ubuntu 12.04 
> use.
> I run dd command (dd if=/dev/zero bs=1M count=6 of=/dev/rbd${i} & )on 
> Ceph client to create data prepare test at last night.
> Now, I have one machine down (can’t be reached by ping), another two machine 
> has all OSD daemon down, while the three left has some daemon down.
>
> I have many warnings in OSD log like this:
>
> no flag points reached
> 2013-01-15 19:14:22.769898 7f20a2d57700  0 log [WRN] : slow request 52.218106 
> seconds old, received at 2013-01-15 19:13:30.551718: 
> osd_op(client.10674.1:1002417 rb.0.27a8.6b8b4567.0eba [write 
> 3145728~524288] 2.c61810ee RETRY) currently waiting for sub ops
> 2013-01-15 19:14:23.770077 7f20a2d57700  0 log [WRN] : 21 slow requests, 6 
> included below; oldest blocked for > 1132.138983 secs
> 2013-01-15 19:14:23.770086 7f20a2d57700  0 log [WRN] : slow request 53.216404 
> seconds old, received at 2013-01-15 19:13:30.553616: 
> osd_op(client.10671.1:1066860 rb.0.282c.6b8b4567.1057 [write 
> 2621440~524288] 2.ea7acebc) currently waiting for sub ops
> 2013-01-15 19:14:23.770096 7f20a2d57700  0 log [WRN] : slow request 51.442032 
> seconds old, received at 2013-01-15 19:13:32.327988: 
> osd_op(client.10674.1:1002418
>
> Similar info in dmesg we have saw pervious:
>
> [21199.036476] INFO: task ceph-osd:7788 blocked for more than 120 seconds.
> [21199.037493] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables 
> this message.
> [21199.038841] ceph-osdD 0006 0  7788  1 
> 0x
> [21199.038844]  880fefdafcc8 0086  
> ffe0
> [21199.038848]  880fefdaffd8 880fefdaffd8 880fefdaffd8 
> 00013780
> [21199.038852]  88081aa58000 880f68f52de0 880f68f52de0 
> 882017556200
> [21199.038856] Call Trace:
> [21199.038858]  [] schedule+0x3f/0x60
> [21199.038861]  [] exit_mm+0x85/0x130
> [21199.038864]  [] do_exit+0x16e/0x420
> [21199.038866]  [] ? __unqueue_futex+0x3f/0x80
> [21199.038869]  [] ? __dequeue_signal+0x6a/0xb0
> [21199.038872]  [] do_group_exit+0x44/0xa0
> [21199.038874]  [] get_signal_to_deliver+0x21c/0x420
> [21199.038877]  [] do_signal+0x45/0x130
> [21199.038880]  [] ? do_futex+0x7c/0x1b0
> [21199.038882]  [] ? sys_futex+0x10a/0x1a0
> [21199.038885]  [] do_notify_resume+0x65/0x80
> [21199.038887]  [] int_signal+0x12/0x17
>
>
> Thanks.
> -chen
>

my 0.02$:
http://www.mail-archive.com/ceph-devel@vger.kernel.org/msg11531.html
and kernel panic from two different hosts from yesterday during ceph
startup(on 3.8-rc3, images from console available at
http://imgur.com/wIRVn,k0QCS#0) leads to suggestion that Ceph may have
been introduced lockup-alike behavior not a long ago, causing, in my
case, excessive amount of context switches on the host leading to osd
flaps and panic at the ip-ib stack due to same issue.
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Re: Ceph slow request & unstable issue

2013-01-16 Thread Sage Weil
Hi,

On Wed, 16 Jan 2013, Andrey Korolyov wrote:
> On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  wrote:
> > Hi list,
> > We are suffering from OSD or OS down when there is continuing high 
> > pressure on the Ceph rack.
> > Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in each 
> > nodes with 20 * spindles + 4* SSDs as journal.(120 spindles in total)
> > We create a lots of RBD volumes (say 240),mounting to 16 different 
> > client machines ( 15 RBD Volumes/ client) and running DD concurrently on 
> > top of each RBD.
> >
> > The issues are:
> > 1. Slow requests
> > ??From the list-archive it seems solved in 0.56.1 but we still notice such 
> > warning
> > 2. OSD Down or even host down
> > Like the message below.Seems some OSD has been blocking there for quite a 
> > long time.
> >
> > Suggestions are highly appreciate.Thanks
> > 
> > 
> > Xiaoxi
> >
> > _
> >
> > Bad news:
> >
> > I have  back all my Ceph machine?s OS to kernel  3.2.0-23, which Ubuntu 
> > 12.04 use.
> > I run dd command (dd if=/dev/zero bs=1M count=6 of=/dev/rbd${i} & )on 
> > Ceph client to create data prepare test at last night.
> > Now, I have one machine down (can?t be reached by ping), another two 
> > machine has all OSD daemon down, while the three left has some daemon down.
> >
> > I have many warnings in OSD log like this:
> >
> > no flag points reached
> > 2013-01-15 19:14:22.769898 7f20a2d57700  0 log [WRN] : slow request 
> > 52.218106 seconds old, received at 2013-01-15 19:13:30.551718: 
> > osd_op(client.10674.1:1002417 rb.0.27a8.6b8b4567.0eba [write 
> > 3145728~524288] 2.c61810ee RETRY) currently waiting for sub ops
> > 2013-01-15 19:14:23.770077 7f20a2d57700  0 log [WRN] : 21 slow requests, 6 
> > included below; oldest blocked for > 1132.138983 secs
> > 2013-01-15 19:14:23.770086 7f20a2d57700  0 log [WRN] : slow request 
> > 53.216404 seconds old, received at 2013-01-15 19:13:30.553616: 
> > osd_op(client.10671.1:1066860 rb.0.282c.6b8b4567.1057 [write 
> > 2621440~524288] 2.ea7acebc) currently waiting for sub ops
> > 2013-01-15 19:14:23.770096 7f20a2d57700  0 log [WRN] : slow request 
> > 51.442032 seconds old, received at 2013-01-15 19:13:32.327988: 
> > osd_op(client.10674.1:1002418
> >
> > Similar info in dmesg we have saw pervious:
> >
> > [21199.036476] INFO: task ceph-osd:7788 blocked for more than 120 seconds.
> > [21199.037493] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables 
> > this message.
> > [21199.038841] ceph-osdD 0006 0  7788  1 
> > 0x
> > [21199.038844]  880fefdafcc8 0086  
> > ffe0
> > [21199.038848]  880fefdaffd8 880fefdaffd8 880fefdaffd8 
> > 00013780
> > [21199.038852]  88081aa58000 880f68f52de0 880f68f52de0 
> > 882017556200
> > [21199.038856] Call Trace:
> > [21199.038858]  [] schedule+0x3f/0x60
> > [21199.038861]  [] exit_mm+0x85/0x130
> > [21199.038864]  [] do_exit+0x16e/0x420
> > [21199.038866]  [] ? __unqueue_futex+0x3f/0x80
> > [21199.038869]  [] ? __dequeue_signal+0x6a/0xb0
> > [21199.038872]  [] do_group_exit+0x44/0xa0
> > [21199.038874]  [] get_signal_to_deliver+0x21c/0x420
> > [21199.038877]  [] do_signal+0x45/0x130
> > [21199.038880]  [] ? do_futex+0x7c/0x1b0
> > [21199.038882]  [] ? sys_futex+0x10a/0x1a0
> > [21199.038885]  [] do_notify_resume+0x65/0x80
> > [21199.038887]  [] int_signal+0x12/0x17

We have seen this stack trace several times over the past 6 months, but 
are not sure what the trigger is.  In principle, the ceph server-side 
daemons shouldn't be capable of locking up like this, but clearly 
something is amiss between what they are doing in userland and how the 
kernel is tolerating that.  Low memory, perhaps?  In each case where we 
tried to track it down, the problem seemed to go away on its own.  Is this 
easily reproducible in your case?

> my 0.02$:
> http://www.mail-archive.com/ceph-devel@vger.kernel.org/msg11531.html
> and kernel panic from two different hosts from yesterday during ceph
> startup(on 3.8-rc3, images from console available at
> http://imgur.com/wIRVn,k0QCS#0) leads to suggestion that Ceph may have
> been introduced lockup-alike behavior not a long ago, causing, in my
> case, excessive amount of context switches on the host leading to osd
> flaps and panic at the ip-ib stack due to same issue.

For the stack trace my first guess would be a problem with the IB driver 
that is triggered by memory pressure.  Can you characterize what the 
system utilization (CPU, memory) looks like leading up to the lockup?

sage
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Re: Ceph slow request & unstable issue

2013-01-16 Thread Andrey Korolyov
On Wed, Jan 16, 2013 at 8:58 PM, Sage Weil  wrote:
> Hi,
>
> On Wed, 16 Jan 2013, Andrey Korolyov wrote:
>> On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  wrote:
>> > Hi list,
>> > We are suffering from OSD or OS down when there is continuing high 
>> > pressure on the Ceph rack.
>> > Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in each 
>> > nodes with 20 * spindles + 4* SSDs as journal.(120 spindles in total)
>> > We create a lots of RBD volumes (say 240),mounting to 16 different 
>> > client machines ( 15 RBD Volumes/ client) and running DD concurrently on 
>> > top of each RBD.
>> >
>> > The issues are:
>> > 1. Slow requests
>> > ??From the list-archive it seems solved in 0.56.1 but we still notice such 
>> > warning
>> > 2. OSD Down or even host down
>> > Like the message below.Seems some OSD has been blocking there for quite a 
>> > long time.
>> >
>> > Suggestions are highly appreciate.Thanks
>> >
>> >
>> >   Xiaoxi
>> >
>> > _
>> >
>> > Bad news:
>> >
>> > I have  back all my Ceph machine?s OS to kernel  3.2.0-23, which Ubuntu 
>> > 12.04 use.
>> > I run dd command (dd if=/dev/zero bs=1M count=6 of=/dev/rbd${i} & )on 
>> > Ceph client to create data prepare test at last night.
>> > Now, I have one machine down (can?t be reached by ping), another two 
>> > machine has all OSD daemon down, while the three left has some daemon down.
>> >
>> > I have many warnings in OSD log like this:
>> >
>> > no flag points reached
>> > 2013-01-15 19:14:22.769898 7f20a2d57700  0 log [WRN] : slow request 
>> > 52.218106 seconds old, received at 2013-01-15 19:13:30.551718: 
>> > osd_op(client.10674.1:1002417 rb.0.27a8.6b8b4567.0eba [write 
>> > 3145728~524288] 2.c61810ee RETRY) currently waiting for sub ops
>> > 2013-01-15 19:14:23.770077 7f20a2d57700  0 log [WRN] : 21 slow requests, 6 
>> > included below; oldest blocked for > 1132.138983 secs
>> > 2013-01-15 19:14:23.770086 7f20a2d57700  0 log [WRN] : slow request 
>> > 53.216404 seconds old, received at 2013-01-15 19:13:30.553616: 
>> > osd_op(client.10671.1:1066860 rb.0.282c.6b8b4567.1057 [write 
>> > 2621440~524288] 2.ea7acebc) currently waiting for sub ops
>> > 2013-01-15 19:14:23.770096 7f20a2d57700  0 log [WRN] : slow request 
>> > 51.442032 seconds old, received at 2013-01-15 19:13:32.327988: 
>> > osd_op(client.10674.1:1002418
>> >
>> > Similar info in dmesg we have saw pervious:
>> >
>> > [21199.036476] INFO: task ceph-osd:7788 blocked for more than 120 seconds.
>> > [21199.037493] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables 
>> > this message.
>> > [21199.038841] ceph-osdD 0006 0  7788  1 
>> > 0x
>> > [21199.038844]  880fefdafcc8 0086  
>> > ffe0
>> > [21199.038848]  880fefdaffd8 880fefdaffd8 880fefdaffd8 
>> > 00013780
>> > [21199.038852]  88081aa58000 880f68f52de0 880f68f52de0 
>> > 882017556200
>> > [21199.038856] Call Trace:
>> > [21199.038858]  [] schedule+0x3f/0x60
>> > [21199.038861]  [] exit_mm+0x85/0x130
>> > [21199.038864]  [] do_exit+0x16e/0x420
>> > [21199.038866]  [] ? __unqueue_futex+0x3f/0x80
>> > [21199.038869]  [] ? __dequeue_signal+0x6a/0xb0
>> > [21199.038872]  [] do_group_exit+0x44/0xa0
>> > [21199.038874]  [] get_signal_to_deliver+0x21c/0x420
>> > [21199.038877]  [] do_signal+0x45/0x130
>> > [21199.038880]  [] ? do_futex+0x7c/0x1b0
>> > [21199.038882]  [] ? sys_futex+0x10a/0x1a0
>> > [21199.038885]  [] do_notify_resume+0x65/0x80
>> > [21199.038887]  [] int_signal+0x12/0x17
>
> We have seen this stack trace several times over the past 6 months, but
> are not sure what the trigger is.  In principle, the ceph server-side
> daemons shouldn't be capable of locking up like this, but clearly
> something is amiss between what they are doing in userland and how the
> kernel is tolerating that.  Low memory, perhaps?  In each case where we
> tried to track it down, the problem seemed to go away on its own.  Is this
> easily reproducible in your case?
>
>> my 0.02$:
>> http://www.mail-archive.com/ceph-devel@vger.kernel.org/msg11531.html
>> and kernel panic from two different hosts from yesterday during ceph
>> startup(on 3.8-rc3, images from console available at
>> http://imgur.com/wIRVn,k0QCS#0) leads to suggestion that Ceph may have
>> been introduced lockup-alike behavior not a long ago, causing, in my
>> case, excessive amount of context switches on the host leading to osd
>> flaps and panic at the ip-ib stack due to same issue.
>
> For the stack trace my first guess would be a problem with the IB driver
> that is triggered by memory pressure.  Can you characterize what the
> system utilization (CPU, memory) looks like leading up to th

Re: Ceph slow request & unstable issue

2013-01-16 Thread Andrey Korolyov
On Wed, Jan 16, 2013 at 10:35 PM, Andrey Korolyov  wrote:
> On Wed, Jan 16, 2013 at 8:58 PM, Sage Weil  wrote:
>> Hi,
>>
>> On Wed, 16 Jan 2013, Andrey Korolyov wrote:
>>> On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  wrote:
>>> > Hi list,
>>> > We are suffering from OSD or OS down when there is continuing 
>>> > high pressure on the Ceph rack.
>>> > Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in each 
>>> > nodes with 20 * spindles + 4* SSDs as journal.(120 spindles in total)
>>> > We create a lots of RBD volumes (say 240),mounting to 16 
>>> > different client machines ( 15 RBD Volumes/ client) and running DD 
>>> > concurrently on top of each RBD.
>>> >
>>> > The issues are:
>>> > 1. Slow requests
>>> > ??From the list-archive it seems solved in 0.56.1 but we still notice 
>>> > such warning
>>> > 2. OSD Down or even host down
>>> > Like the message below.Seems some OSD has been blocking there for quite a 
>>> > long time.
>>> >
>>> > Suggestions are highly appreciate.Thanks
>>> >   
>>> >   
>>> > Xiaoxi
>>> >
>>> > _
>>> >
>>> > Bad news:
>>> >
>>> > I have  back all my Ceph machine?s OS to kernel  3.2.0-23, which Ubuntu 
>>> > 12.04 use.
>>> > I run dd command (dd if=/dev/zero bs=1M count=6 of=/dev/rbd${i} & )on 
>>> > Ceph client to create data prepare test at last night.
>>> > Now, I have one machine down (can?t be reached by ping), another two 
>>> > machine has all OSD daemon down, while the three left has some daemon 
>>> > down.
>>> >
>>> > I have many warnings in OSD log like this:
>>> >
>>> > no flag points reached
>>> > 2013-01-15 19:14:22.769898 7f20a2d57700  0 log [WRN] : slow request 
>>> > 52.218106 seconds old, received at 2013-01-15 19:13:30.551718: 
>>> > osd_op(client.10674.1:1002417 rb.0.27a8.6b8b4567.0eba [write 
>>> > 3145728~524288] 2.c61810ee RETRY) currently waiting for sub ops
>>> > 2013-01-15 19:14:23.770077 7f20a2d57700  0 log [WRN] : 21 slow requests, 
>>> > 6 included below; oldest blocked for > 1132.138983 secs
>>> > 2013-01-15 19:14:23.770086 7f20a2d57700  0 log [WRN] : slow request 
>>> > 53.216404 seconds old, received at 2013-01-15 19:13:30.553616: 
>>> > osd_op(client.10671.1:1066860 rb.0.282c.6b8b4567.1057 [write 
>>> > 2621440~524288] 2.ea7acebc) currently waiting for sub ops
>>> > 2013-01-15 19:14:23.770096 7f20a2d57700  0 log [WRN] : slow request 
>>> > 51.442032 seconds old, received at 2013-01-15 19:13:32.327988: 
>>> > osd_op(client.10674.1:1002418
>>> >
>>> > Similar info in dmesg we have saw pervious:
>>> >
>>> > [21199.036476] INFO: task ceph-osd:7788 blocked for more than 120 seconds.
>>> > [21199.037493] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" 
>>> > disables this message.
>>> > [21199.038841] ceph-osdD 0006 0  7788  1 
>>> > 0x
>>> > [21199.038844]  880fefdafcc8 0086  
>>> > ffe0
>>> > [21199.038848]  880fefdaffd8 880fefdaffd8 880fefdaffd8 
>>> > 00013780
>>> > [21199.038852]  88081aa58000 880f68f52de0 880f68f52de0 
>>> > 882017556200
>>> > [21199.038856] Call Trace:
>>> > [21199.038858]  [] schedule+0x3f/0x60
>>> > [21199.038861]  [] exit_mm+0x85/0x130
>>> > [21199.038864]  [] do_exit+0x16e/0x420
>>> > [21199.038866]  [] ? __unqueue_futex+0x3f/0x80
>>> > [21199.038869]  [] ? __dequeue_signal+0x6a/0xb0
>>> > [21199.038872]  [] do_group_exit+0x44/0xa0
>>> > [21199.038874]  [] get_signal_to_deliver+0x21c/0x420
>>> > [21199.038877]  [] do_signal+0x45/0x130
>>> > [21199.038880]  [] ? do_futex+0x7c/0x1b0
>>> > [21199.038882]  [] ? sys_futex+0x10a/0x1a0
>>> > [21199.038885]  [] do_notify_resume+0x65/0x80
>>> > [21199.038887]  [] int_signal+0x12/0x17
>>
>> We have seen this stack trace several times over the past 6 months, but
>> are not sure what the trigger is.  In principle, the ceph server-side
>> daemons shouldn't be capable of locking up like this, but clearly
>> something is amiss between what they are doing in userland and how the
>> kernel is tolerating that.  Low memory, perhaps?  In each case where we
>> tried to track it down, the problem seemed to go away on its own.  Is this
>> easily reproducible in your case?
>>
>>> my 0.02$:
>>> http://www.mail-archive.com/ceph-devel@vger.kernel.org/msg11531.html
>>> and kernel panic from two different hosts from yesterday during ceph
>>> startup(on 3.8-rc3, images from console available at
>>> http://imgur.com/wIRVn,k0QCS#0) leads to suggestion that Ceph may have
>>> been introduced lockup-alike behavior not a long ago, causing, in my
>>> case, excessive amount of context switches on the host leading to osd
>>> flaps and panic at the ip-ib stack due to same issue.
>>
>> For the stack trace my first guess would

RE: Ceph slow request & unstable issue

2013-01-16 Thread Chen, Xiaoxi
Hi Sage,
Both CPU and Memory utilization are very low. CPU is ~ 20% (with 60% 
IOWAIT), Memory is far more less . I have 32 Core Sandybridege CPU(64 Core for 
HT), together with 128GB RAM per node.



Xiaoxi

-Original Message-
From: Sage Weil [mailto:s...@inktank.com] 
Sent: 2013年1月17日 0:59
To: Andrey Korolyov
Cc: Chen, Xiaoxi; ceph-devel@vger.kernel.org
Subject: Re: Ceph slow request & unstable issue

Hi,

On Wed, 16 Jan 2013, Andrey Korolyov wrote:
> On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  wrote:
> > Hi list,
> > We are suffering from OSD or OS down when there is continuing high 
> > pressure on the Ceph rack.
> > Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in each 
> > nodes with 20 * spindles + 4* SSDs as journal.(120 spindles in total)
> > We create a lots of RBD volumes (say 240),mounting to 16 different 
> > client machines ( 15 RBD Volumes/ client) and running DD concurrently on 
> > top of each RBD.
> >
> > The issues are:
> > 1. Slow requests
> > ??From the list-archive it seems solved in 0.56.1 but we still 
> > notice such warning 2. OSD Down or even host down Like the message 
> > below.Seems some OSD has been blocking there for quite a long time.
> >
> > Suggestions are highly appreciate.Thanks
> > 
> > 
> > 
> > Xiaoxi
> >
> > _
> >
> > Bad news:
> >
> > I have  back all my Ceph machine?s OS to kernel  3.2.0-23, which Ubuntu 
> > 12.04 use.
> > I run dd command (dd if=/dev/zero bs=1M count=6 of=/dev/rbd${i} & )on 
> > Ceph client to create data prepare test at last night.
> > Now, I have one machine down (can?t be reached by ping), another two 
> > machine has all OSD daemon down, while the three left has some daemon down.
> >
> > I have many warnings in OSD log like this:
> >
> > no flag points reached
> > 2013-01-15 19:14:22.769898 7f20a2d57700  0 log [WRN] : slow request 
> > 52.218106 seconds old, received at 2013-01-15 19:13:30.551718: 
> > osd_op(client.10674.1:1002417 rb.0.27a8.6b8b4567.0eba [write 
> > 3145728~524288] 2.c61810ee RETRY) currently waiting for sub ops
> > 2013-01-15 19:14:23.770077 7f20a2d57700  0 log [WRN] : 21 slow 
> > requests, 6 included below; oldest blocked for > 1132.138983 secs
> > 2013-01-15 19:14:23.770086 7f20a2d57700  0 log [WRN] : slow request 
> > 53.216404 seconds old, received at 2013-01-15 19:13:30.553616: 
> > osd_op(client.10671.1:1066860 rb.0.282c.6b8b4567.1057 [write 
> > 2621440~524288] 2.ea7acebc) currently waiting for sub ops
> > 2013-01-15 19:14:23.770096 7f20a2d57700  0 log [WRN] : slow request 
> > 51.442032 seconds old, received at 2013-01-15 19:13:32.327988: 
> > osd_op(client.10674.1:1002418
> >
> > Similar info in dmesg we have saw pervious:
> >
> > [21199.036476] INFO: task ceph-osd:7788 blocked for more than 120 seconds.
> > [21199.037493] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables 
> > this message.
> > [21199.038841] ceph-osdD 0006 0  7788  1 
> > 0x
> > [21199.038844]  880fefdafcc8 0086  
> > ffe0 [21199.038848]  880fefdaffd8 880fefdaffd8 
> > 880fefdaffd8 00013780 [21199.038852]  88081aa58000 
> > 880f68f52de0 880f68f52de0 882017556200 [21199.038856] Call 
> > Trace:
> > [21199.038858]  [] schedule+0x3f/0x60 
> > [21199.038861]  [] exit_mm+0x85/0x130 
> > [21199.038864]  [] do_exit+0x16e/0x420 
> > [21199.038866]  [] ? __unqueue_futex+0x3f/0x80 
> > [21199.038869]  [] ? __dequeue_signal+0x6a/0xb0 
> > [21199.038872]  [] do_group_exit+0x44/0xa0 
> > [21199.038874]  [] 
> > get_signal_to_deliver+0x21c/0x420 [21199.038877]  
> > [] do_signal+0x45/0x130 [21199.038880]  
> > [] ? do_futex+0x7c/0x1b0 [21199.038882]  
> > [] ? sys_futex+0x10a/0x1a0 [21199.038885]  
> > [] do_notify_resume+0x65/0x80 [21199.038887]  
> > [] int_signal+0x12/0x17

We have seen this stack trace several times over the past 6 months, but are not 
sure what the trigger is.  In principle, the ceph server-side 

RE: Ceph slow request & unstable issue

2013-01-16 Thread Sage Weil
On Thu, 17 Jan 2013, Chen, Xiaoxi wrote:
> Hi Sage?
>   Both CPU and Memory utilization are very low. CPU is ~ 20% (with 
> 60% IOWAIT), Memory is far more less . I have 32 Core Sandybridege 
> CPU(64 Core for HT), together with 128GB RAM per node.

Hmm!

> -Original Message-
> From: Sage Weil [mailto:s...@inktank.com] 
> Sent: 2013?1?17? 0:59
> To: Andrey Korolyov
> Cc: Chen, Xiaoxi; ceph-devel@vger.kernel.org
> Subject: Re: Ceph slow request & unstable issue
> 
> Hi,
> 
> On Wed, 16 Jan 2013, Andrey Korolyov wrote:
> > On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  wrote:
> > > Hi list,
> > > We are suffering from OSD or OS down when there is continuing 
> > > high pressure on the Ceph rack.
> > > Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in each 
> > > nodes with 20 * spindles + 4* SSDs as journal.(120 spindles in total)
> > > We create a lots of RBD volumes (say 240),mounting to 16 
> > > different client machines ( 15 RBD Volumes/ client) and running DD 
> > > concurrently on top of each RBD.
> > >
> > > The issues are:
> > > 1. Slow requests
> > > ??From the list-archive it seems solved in 0.56.1 but we still 
> > > notice such warning 2. OSD Down or even host down Like the message 
> > > below.Seems some OSD has been blocking there for quite a long time.

There is still an issue with throttling recovery/migration traffic 
leading to the slow requests that should be fixed shortly.

> > > Suggestions are highly appreciate.Thanks
> > >   
> > >   
> > > 
> > > Xiaoxi
> > >
> > > _
> > >
> > > Bad news:
> > >
> > > I have  back all my Ceph machine?s OS to kernel  3.2.0-23, which Ubuntu 
> > > 12.04 use.
> > > I run dd command (dd if=/dev/zero bs=1M count=6 of=/dev/rbd${i} & )on 
> > > Ceph client to create data prepare test at last night.

Oooh, you are running the kernel RBD client on a 3.2 kernel.  There have 
been a long series of fixes since then, but we've only backported as far 
back as 3.4.  Can you try a newer kernel version for the client?  
Something a recnet 3.4 or 3.7 series, like 3.7.2 or 3.4.25... 

Thanks!

> > > Now, I have one machine down (can?t be reached by ping), another two 
> > > machine has all OSD daemon down, while the three left has some daemon 
> > > down.
> > >
> > > I have many warnings in OSD log like this:
> > >
> > > no flag points reached
> > > 2013-01-15 19:14:22.769898 7f20a2d57700  0 log [WRN] : slow request 
> > > 52.218106 seconds old, received at 2013-01-15 19:13:30.551718: 
> > > osd_op(client.10674.1:1002417 rb.0.27a8.6b8b4567.0eba [write 
> > > 3145728~524288] 2.c61810ee RETRY) currently waiting for sub ops
> > > 2013-01-15 19:14:23.770077 7f20a2d57700  0 log [WRN] : 21 slow 
> > > requests, 6 included below; oldest blocked for > 1132.138983 secs
> > > 2013-01-15 19:14:23.770086 7f20a2d57700  0 log [WRN] : slow request 
> > > 53.216404 seconds old, received at 2013-01-15 19:13:30.553616: 
> > > osd_op(client.10671.1:1066860 rb.0.282c.6b8b4567.1057 [write 
> > > 2621440~524288] 2.ea7acebc) currently waiting for sub ops
> > > 2013-01-15 19:14:23.770096 7f20a2d57700  0 log [WRN] : slow request 
> > > 51.442032 seconds old, received at 2013-01-15 19:13:32.327988: 
> > > osd_op(client.10674.1:1002418
> > >
> > > Similar info in dmesg we have saw pervious:
> > >
> > > [21199.036476] INFO: task ceph-osd:7788 blocked for more than 120 seconds.
> > > [21199.037493] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" 
> > > disables this message.
> > > [21199.038841] ceph-osdD 0006 0  7788  1 
> > > 0x
> > > [21199.038844]  880fefdafcc8 0086  
> > > ffe0 [21199.038848]  880fefdaffd8 880fefdaffd8 
> > > 880fefdaffd8 00013780 [21199.038852]  88081aa58000 
> > > 880f68f52de0 880f68f52de0 882017556200 [21199.038856] Call 
> > > Trace:
> > > [21199.038858]  [] schedule+0x3f/0x60 
> > > [21199.038861]  [] exit_mm+0x85/0x130 
> > > [21199.038864]  [] do_exit+0x16e/0x420 
> > > [21199.038866]  [] ? __unqueue_futex+0x3f/0x80 
&g

RE: Ceph slow request & unstable issue

2013-01-16 Thread Chen, Xiaoxi
Some update& summary for tested case till now:
Ceph is v0.56.1

1.  RBD:Ubuntu 13.04 + 3.7Kernel 
OSD:Ubuntu 13.04 + 3.7Kernel
XFS

Result: Kernel Panic on both RBD and OSD sides

2.  RBD:Ubuntu 13.04 +3.2Kernel
OSD:Ubuntu 13.04 +3.2Kernel
XFS

Result:Kernel Panic on RBD( ~15Minus)

3.  RBD:Ubuntu 13.04 + 3.6.7 Kernel (Suggested by Ceph.com)
OSD:Ubuntu 13.04 + 3.2   Kernel 
XFS

Result: Auto-reset on OSD ( ~ 30 mins after the test started)

4.  RBD:Ubuntu 13.04+3.6.7 Kernel (Suggested by Ceph.com)
OSD:Ubuntu 12.04 + 3.2.0-36 Kernel (Suggested by Ceph.com)
XFS

Result:auto-reset on OSD ( ~ 30 mins after the test started)

5.  RBD:Ubuntu 13.04+3.6.7 Kernel (Suggested by Ceph.com)
OSD:Ubuntu 13.04 +3.6.7 (Suggested by Sage)
XFS

Result: seems stable for last 1 hour, still running till now


Test 3&4 are repeatable.
My test setup 
OSD side:
  3 nodes, 60 Disks(20 per nodes,1 per OSD),10Gb E, 4 *Intel 520 SSD per node 
as journal,XFS
  For each node,2 * Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GH + 128GB RAM were 
used.
RBD side:
  8 nodes,for each node:10Gb E,2 * Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GH , 
128GB RAM

Method:
Create 240 RBD and mounted to 8 nodes ( 30 RBD per nodes), doing DD 
concurrently on all 240 RBDs.

After ~ 30 minutes, it's likely to have one of the OSD node reset.

Ceph OSD logs, syslog and dmesg from reseted node are available if you 
needed.(It looks to me that no valuable information except a lot of 
slow-request in OSD's log)



Xiaoxi


-Original Message-
From: Sage Weil [mailto:s...@inktank.com] 
Sent: 2013年1月17日 10:35
To: Chen, Xiaoxi
Subject: RE: Ceph slow request & unstable issue

On Thu, 17 Jan 2013, Chen, Xiaoxi wrote:
> No, on the OSD node, not the same node. OSD node with 3.2 kernel while 
> client node with 3.6 kernel
> 
> We did suffer kernel panic on rbd client nodes but after upgrade 
> client kernel to 3.6.6 it seems solved .

Is it easy to try the 3.6 kernel on the osd nodes too?


> 
> 
> -Original Message-
> From: Sage Weil [mailto:s...@inktank.com]
> Sent: 2013?1?17? 10:17
> To: Chen, Xiaoxi
> Subject: RE: Ceph slow request & unstable issue
> 
> On Thu, 17 Jan 2013, Chen, Xiaoxi wrote:
> > It is easily to reproduce in my setup...
> > Once I have enough high load on it and waiting for tens of minutes? I can 
> > see such log.
> > As a forecast, "slow requests" more than 30~60s  are frequently present in 
> > ceph osd's log.
> 
> Just replied to your other email.  Do I understand correctly that you are 
> seeing this problem on the *rbd client* nodes?  Or also on the OSDs?  Are 
> they the same nodes?
> 
> sage
> 
> > 
> > -Original Message-
> > From: Sage Weil [mailto:s...@inktank.com]
> > Sent: 2013?1?17? 0:59
> > To: Andrey Korolyov
> > Cc: Chen, Xiaoxi; ceph-devel@vger.kernel.org
> > Subject: Re: Ceph slow request & unstable issue
> > 
> > Hi,
> > 
> > On Wed, 16 Jan 2013, Andrey Korolyov wrote:
> > > On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  
> > > wrote:
> > > > Hi list,
> > > > We are suffering from OSD or OS down when there is continuing 
> > > > high pressure on the Ceph rack.
> > > > Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in each 
> > > > nodes with 20 * spindles + 4* SSDs as journal.(120 spindles in total)
> > > > We create a lots of RBD volumes (say 240),mounting to 16 
> > > > different client machines ( 15 RBD Volumes/ client) and running DD 
> > > > concurrently on top of each RBD.
> > > >
> > > > The issues are:
> > > > 1. Slow requests
> > > > ??From the list-archive it seems solved in 0.56.1 but we still 
> > > > notice such warning 2. OSD Down or even host down Like the 
> > > > message below.Seems some OSD has been blocking there for quite a long 
> > > > time.
> > > >
> > > > Suggestions are highly appreciate.Thanks
> > > > 
> > > > 
> > > > 
> > > > Xiaoxi
> > > >
> > > > _
> > > >
> > > > Bad news:
> > > >
> 

RE: Ceph slow request & unstable issue

2013-01-17 Thread Sage Weil
On Thu, 17 Jan 2013, Chen, Xiaoxi wrote:
> Some update& summary for tested case till now:
> Ceph is v0.56.1
> 
> 1.RBD:Ubuntu 13.04 + 3.7Kernel 
>   OSD:Ubuntu 13.04 + 3.7Kernel
>   XFS
> 
>   Result: Kernel Panic on both RBD and OSD sides

We're very interested in the RBD client-side kernel panic!  I don't think 
there are known issues with 3.7.

> 2.RBD:Ubuntu 13.04 +3.2Kernel
>   OSD:Ubuntu 13.04 +3.2Kernel
>   XFS
>   
>   Result:Kernel Panic on RBD( ~15Minus)

This less so; we've only backported fixes as far as 3.4.

> 3.RBD:Ubuntu 13.04 + 3.6.7 Kernel (Suggested by Ceph.com)
>   OSD:Ubuntu 13.04 + 3.2   Kernel 
>   XFS
> 
>   Result: Auto-reset on OSD ( ~ 30 mins after the test started)
> 
> 4.RBD:Ubuntu 13.04+3.6.7 Kernel (Suggested by Ceph.com)
>   OSD:Ubuntu 12.04 + 3.2.0-36 Kernel (Suggested by Ceph.com)
>   XFS
>   
>   Result:auto-reset on OSD ( ~ 30 mins after the test started)

These the the weird exit_mm traces shown below?

> 5.RBD:Ubuntu 13.04+3.6.7 Kernel (Suggested by Ceph.com)
>   OSD:Ubuntu 13.04 +3.6.7 (Suggested by Sage)
>   XFS
> 
>   Result: seems stable for last 1 hour, still running till now

Eager to hear how this goes.

Thanks!
sage


> 
> 
> Test 3&4 are repeatable.
> My test setup 
> OSD side:
>   3 nodes, 60 Disks(20 per nodes,1 per OSD),10Gb E, 4 *Intel 520 SSD per node 
> as journal,XFS
>   For each node,2 * Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GH + 128GB RAM were 
> used.
> RBD side:
>   8 nodes,for each node:10Gb E,2 * Intel(R) Xeon(R) CPU E5-2670 0 @ 2.60GH , 
> 128GB RAM
> 
> Method:
>   Create 240 RBD and mounted to 8 nodes ( 30 RBD per nodes), doing DD 
> concurrently on all 240 RBDs.
> 
>   After ~ 30 minutes, it's likely to have one of the OSD node reset.
> 
> Ceph OSD logs, syslog and dmesg from reseted node are available if you 
> needed.(It looks to me that no valuable information except a lot of 
> slow-request in OSD's log)
> 
> 
>   
>                 Xiaoxi
> 
> 
> -Original Message-
> From: Sage Weil [mailto:s...@inktank.com] 
> Sent: 2013?1?17? 10:35
> To: Chen, Xiaoxi
> Subject: RE: Ceph slow request & unstable issue
> 
> On Thu, 17 Jan 2013, Chen, Xiaoxi wrote:
> > No, on the OSD node, not the same node. OSD node with 3.2 kernel while 
> > client node with 3.6 kernel
> > 
> > We did suffer kernel panic on rbd client nodes but after upgrade 
> > client kernel to 3.6.6 it seems solved .
> 
> Is it easy to try the 3.6 kernel on the osd nodes too?
> 
> 
> > 
> > 
> > -Original Message-
> > From: Sage Weil [mailto:s...@inktank.com]
> > Sent: 2013?1?17? 10:17
> > To: Chen, Xiaoxi
> > Subject: RE: Ceph slow request & unstable issue
> > 
> > On Thu, 17 Jan 2013, Chen, Xiaoxi wrote:
> > > It is easily to reproduce in my setup...
> > > Once I have enough high load on it and waiting for tens of minutes? I can 
> > > see such log.
> > > As a forecast, "slow requests" more than 30~60s  are frequently present 
> > > in ceph osd's log.
> > 
> > Just replied to your other email.  Do I understand correctly that you are 
> > seeing this problem on the *rbd client* nodes?  Or also on the OSDs?  Are 
> > they the same nodes?
> > 
> > sage
> > 
> > > 
> > > -Original Message-
> > > From: Sage Weil [mailto:s...@inktank.com]
> > > Sent: 2013?1?17? 0:59
> > > To: Andrey Korolyov
> > > Cc: Chen, Xiaoxi; ceph-devel@vger.kernel.org
> > > Subject: Re: Ceph slow request & unstable issue
> > > 
> > > Hi,
> > > 
> > > On Wed, 16 Jan 2013, Andrey Korolyov wrote:
> > > > On Wed, Jan 16, 2013 at 4:58 AM, Chen, Xiaoxi  
> > > > wrote:
> > > > > Hi list,
> > > > > We are suffering from OSD or OS down when there is continuing 
> > > > > high pressure on the Ceph rack.
> > > > > Basically we are on Ubuntu 12.04+ Ceph 0.56.1, 6 nodes, in 
> > > > > each nodes with 20 * spindles + 4* SSDs as journal.(120 spindles in 
> > > > > total)
> > > > > We create a lots of RBD volumes (say 240),mounting to 16 
> > > > > different client machines ( 15 RBD Volumes/ client) and running DD 
> > > > > concurrently on top of each RBD.
> > > > >