Re: rbd map command hangs for 15 minutes during system start up

[Alex Elder <elder@inktank.com>]

On 11/29/2012 02:37 PM, Alex Elder wrote:
> On 11/22/2012 12:04 PM, Nick Bartos wrote:
>> Here are the ceph log messages (including the libceph kernel debug
>> stuff you asked for) from a node boot with the rbd command hung for a
>> couple of minutes:

I'm sorry, but I did something stupid...

Yes, the branch I gave you includes these fixes.  However
it does *not* include the commit that was giving you trouble
to begin with.

So...

I have updated that same branch (wip-nick) to contain:
- Linux 3.5.5
- Plus the first *50* (not 49) patches you listed
- Plus the ones I added before.

The new commit id for that branch begins with be3198d6.

I'm really sorry for this mistake.  Please try this new
branch and report back what you find.

					-Alex


> Nick, I have put together a branch that includes two fixes
> that might be helpful.  I don't expect these fixes will
> necessarily *fix* what you're seeing, but one of them
> pulls a big hunk of processing out of the picture and
> might help eliminate some potential causes.  I had to
> pull in several other patches as prerequisites in order
> to get those fixes to apply cleanly.
> 
> Would you be able to give it a try, and let us know what
> results you get?  The branch contains:
> - Linux 3.5.5
> - Plus the first 49 patches you listed
> - Plus four patches, which are prerequisites...
>     libceph: define ceph_extract_encoded_string()
>     rbd: define some new format constants
>     rbd: define rbd_dev_image_id()
>     rbd: kill create_snap sysfs entry
> - ...for these two bug fixes:
>     libceph: remove 'osdtimeout' option
>     ceph: don't reference req after put
> 
> The branch is available in the ceph-client git repository
> under the name "wip-nick" and has commit id dd9323aa.
>     https://github.com/ceph/ceph-client/tree/wip-nick
> 
>> https://raw.github.com/gist/4132395/7cb5f0150179b012429c6e57749120dd88616cce/gistfile1.txt
> 
> This full debug output is very helpful.  Please supply
> that again as well.
> 
> Thanks.
> 
> 					-Alex
> 
>> On Wed, Nov 21, 2012 at 9:49 PM, Nick Bartos <nick@pistoncloud.com> wrote:
>>> It's very easy to reproduce now with my automated install script, the
>>> most I've seen it succeed with that patch is 2 in a row, and hanging
>>> on the 3rd, although it hangs on most builds.  So it shouldn't take
>>> much to get it to do it again.  I'll try and get to that tomorrow,
>>> when I'm a bit more rested and my brain is working better.
>>>
>>> Yes during this the OSDs are probably all syncing up.  All the osd and
>>> mon daemons have started by the time the rdb commands are ran, though.
>>>
>>> On Wed, Nov 21, 2012 at 8:47 PM, Sage Weil <sage@inktank.com> wrote:
>>>> On Wed, 21 Nov 2012, Nick Bartos wrote:
>>>>> FYI the build which included all 3.5 backports except patch #50 is
>>>>> still going strong after 21 builds.
>>>>
>>>> Okay, that one at least makes some sense.  I've opened
>>>>
>>>>         http://tracker.newdream.net/issues/3519
>>>>
>>>> How easy is this to reproduce?  If it is something you can trigger with
>>>> debugging enabled ('echo module libceph +p >
>>>> /sys/kernel/debug/dynamic_debug/control') that would help tremendously.
>>>>
>>>> I'm guessing that during this startup time the OSDs are still in the
>>>> process of starting?
>>>>
>>>> Alex, I bet that a test that does a lot of map/unmap stuff in a loop while
>>>> thrashing OSDs could hit this.
>>>>
>>>> Thanks!
>>>> sage
>>>>
>>>>
>>>>>
>>>>> On Wed, Nov 21, 2012 at 9:34 AM, Nick Bartos <nick@pistoncloud.com> wrote:
>>>>>> With 8 successful installs already done, I'm reasonably confident that
>>>>>> it's patch #50.  I'm making another build which applies all patches
>>>>>> from the 3.5 backport branch, excluding that specific one.  I'll let
>>>>>> you know if that turns up any unexpected failures.
>>>>>>
>>>>>> What will the potential fall out be for removing that specific patch?
>>>>>>
>>>>>>
>>>>>> On Wed, Nov 21, 2012 at 9:02 AM, Nick Bartos <nick@pistoncloud.com> wrote:
>>>>>>> It's really looking like it's the
>>>>>>> libceph_resubmit_linger_ops_when_pg_mapping_changes commit.  When
>>>>>>> patches 1-50 (listed below) are applied to 3.5.7, the hang is present.
>>>>>>>  So far I have gone through 4 successful installs with no hang with
>>>>>>> only 1-49 applied.  I'm still leaving my test run to make sure it's
>>>>>>> not a fluke, but since previously it hangs within the first couple of
>>>>>>> builds, it really looks like this is where the problem originated.
>>>>>>>
>>>>>>> 1-libceph_eliminate_connection_state_DEAD.patch
>>>>>>> 2-libceph_kill_bad_proto_ceph_connection_op.patch
>>>>>>> 3-libceph_rename_socket_callbacks.patch
>>>>>>> 4-libceph_rename_kvec_reset_and_kvec_add_functions.patch
>>>>>>> 5-libceph_embed_ceph_messenger_structure_in_ceph_client.patch
>>>>>>> 6-libceph_start_separating_connection_flags_from_state.patch
>>>>>>> 7-libceph_start_tracking_connection_socket_state.patch
>>>>>>> 8-libceph_provide_osd_number_when_creating_osd.patch
>>>>>>> 9-libceph_set_CLOSED_state_bit_in_con_init.patch
>>>>>>> 10-libceph_embed_ceph_connection_structure_in_mon_client.patch
>>>>>>> 11-libceph_drop_connection_refcounting_for_mon_client.patch
>>>>>>> 12-libceph_init_monitor_connection_when_opening.patch
>>>>>>> 13-libceph_fully_initialize_connection_in_con_init.patch
>>>>>>> 14-libceph_tweak_ceph_alloc_msg.patch
>>>>>>> 15-libceph_have_messages_point_to_their_connection.patch
>>>>>>> 16-libceph_have_messages_take_a_connection_reference.patch
>>>>>>> 17-libceph_make_ceph_con_revoke_a_msg_operation.patch
>>>>>>> 18-libceph_make_ceph_con_revoke_message_a_msg_op.patch
>>>>>>> 19-libceph_fix_overflow_in___decode_pool_names.patch
>>>>>>> 20-libceph_fix_overflow_in_osdmap_decode.patch
>>>>>>> 21-libceph_fix_overflow_in_osdmap_apply_incremental.patch
>>>>>>> 22-libceph_transition_socket_state_prior_to_actual_connect.patch
>>>>>>> 23-libceph_fix_NULL_dereference_in_reset_connection.patch
>>>>>>> 24-libceph_use_con_get_put_methods.patch
>>>>>>> 25-libceph_drop_ceph_con_get_put_helpers_and_nref_member.patch
>>>>>>> 26-libceph_encapsulate_out_message_data_setup.patch
>>>>>>> 27-libceph_encapsulate_advancing_msg_page.patch
>>>>>>> 28-libceph_don_t_mark_footer_complete_before_it_is.patch
>>>>>>> 29-libceph_move_init_bio__functions_up.patch
>>>>>>> 30-libceph_move_init_of_bio_iter.patch
>>>>>>> 31-libceph_don_t_use_bio_iter_as_a_flag.patch
>>>>>>> 32-libceph_SOCK_CLOSED_is_a_flag_not_a_state.patch
>>>>>>> 33-libceph_don_t_change_socket_state_on_sock_event.patch
>>>>>>> 34-libceph_just_set_SOCK_CLOSED_when_state_changes.patch
>>>>>>> 35-libceph_don_t_touch_con_state_in_con_close_socket.patch
>>>>>>> 36-libceph_clear_CONNECTING_in_ceph_con_close.patch
>>>>>>> 37-libceph_clear_NEGOTIATING_when_done.patch
>>>>>>> 38-libceph_define_and_use_an_explicit_CONNECTED_state.patch
>>>>>>> 39-libceph_separate_banner_and_connect_writes.patch
>>>>>>> 40-libceph_distinguish_two_phases_of_connect_sequence.patch
>>>>>>> 41-libceph_small_changes_to_messenger.c.patch
>>>>>>> 42-libceph_add_some_fine_ASCII_art.patch
>>>>>>> 43-libceph_set_peer_name_on_con_open_not_init.patch
>>>>>>> 44-libceph_initialize_mon_client_con_only_once.patch
>>>>>>> 45-libceph_allow_sock_transition_from_CONNECTING_to_CLOSED.patch
>>>>>>> 46-libceph_initialize_msgpool_message_types.patch
>>>>>>> 47-libceph_prevent_the_race_of_incoming_work_during_teardown.patch
>>>>>>> 48-libceph_report_socket_read_write_error_message.patch
>>>>>>> 49-libceph_fix_mutex_coverage_for_ceph_con_close.patch
>>>>>>> 50-libceph_resubmit_linger_ops_when_pg_mapping_changes.patch
>>>>>>>
>>>>>>>
>>>>>>> On Wed, Nov 21, 2012 at 8:50 AM, Sage Weil <sage@inktank.com> wrote:
>>>>>>>> Thanks for hunting this down.  I'm very curious what the culprit is...
>>>>>>>>
>>>>>>>> sage
>>>>>
>>>>>
>