Hi,
There are two aspects of this issue a) core is generated for IMCN. This is
beacause IMCN as an NTF client got stuck in NtfSend() for about 10 seconds.
Other aspect b) both active and standby NTFS got stuck because of circular
dependecny. This second part means NTF service was not available for about 10
seconds. There may be other NTF clients (other than IMCN) that will also be
waiting for using NTF service. Making timeout for IMCN to 6ses will reduce this
unavailablity of NTFS to 6 seconds only but will not solve it completely. Other
clients may crash.
Regarding the exit of IMCN process on role change so that there should not be
two active IMCN in the system: it can be done when IMCN gets quisced role
change information through RDE callback because if it waits for termination
till standby then active would already be up. This seems to be the only
possbility.
Thanks,
Praveen
---
** [tickets:#2219] ntfd: circular dependency with osafntfimcnd**
**Status:** assigned
**Milestone:** 5.0.2
**Created:** Thu Dec 08, 2016 05:14 AM UTC by Gary Lee
**Last Updated:** Thu Dec 15, 2016 12:01 PM UTC
**Owner:** Praveen
A circular dependency can be seen when performing a si-swap of
safSi=SC-2N,safApp=OpenSAF:
1. Active NTFD is trying to sync with Standby using MBC
2. Standby NTFD is the process of terminating its local osafntfimcnd. It is
stuck in timedwait_imcn_exit() and cannot reply to the Active.
3. osafntfimcnd [on standby] is trying to send a notfication to Active NTFD
So we have (1) depending on (2) depending on (3) depending on (1)
This results in a temporary deadlock that dramatically slows down NTFD's
ability to process its main dispatch loop. The deadlock only lasts for approx.
1 second, when mbcsv_mds_send_msg() times out. But since there could be lots of
MBC messages to send, sometimes osafntfimcnd is killed with SIGABRT generating
a coredump. The si-swap operation will also timeout.
steps to reproduce
- Run loop of ntftest 32
root@SC-1:~# for i in {1..10}; do ntftest 32; done
- On another terminal, keep swapping 2N Opensaf SI, got coredump after couples
of swaps
root@SC-1:~# amf-adm si-swap safSi=SC-2N,safApp=OpenSAF
...
root@SC-1:~# amf-adm si-swap safSi=SC-2N,safApp=OpenSAF
~~~
SC-2 (active)
There are a lot of send failures. Each taking approx. 1 second to timeout.
During these 1 second timeouts, NTFD cannot process the main dispatch loop.
Dec 7 11:01:37.531772 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:37.531781 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:38.537307 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:38.537758 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:38.537766 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:39.543180 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:39.543695 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:39.543698 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:40.545252 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:40.545719 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:40.545726 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:41.551328 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:41.551971 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:41.551979 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:42.557594 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:42.558171 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:42.558179 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:43.564051 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:43.564874 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:43.564883 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:44.572407 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:44.573262 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
Dec 7 11:01:44.573271 osafntfd [452:mbcsv_mds.c:0209] TR send type
MDS_SENDTYPE_REDRSP:
Dec 7 11:01:45.575091 osafntfd [452:mbcsv_mds.c:0247] <<
mbcsv_mds_send_msg: failure
Dec 7 11:01:47.083548 osafntfd [452:mbcsv_mds.c:0185] >>
mbcsv_mds_send_msg: sending to vdest:e
~~~
~~~
SC-1 (standby)
NTFD is trying to terminate osafntfimcnd. While it is doing that, it cannot
reply to NTFD on SC-2. Meanwhile, osafntfimcnd is sending NTF notifications to
NTFD on SC-1.
Dec 7 11:01:35.453151 osafntfd [464:ntfs_imcnutil.c:0316] TR
handle_state_ntfimcn: Terminating osafntfimcnd process
Dec 7 11:01:45.474313 osafntfd [464:ntfs_imcnutil.c:0124] TR Termination
timeout
Dec 7 11:01:45.474375 osafntfd [464:ntfs_imcnutil.c:0130] <<
wait_imcnproc_termination: rc = -1, retry_cnt = 101
Dec 7 11:01:45.474387 osafntfd [464:ntfs_imcnutil.c:0168] TR Normal
termination failed. Escalate to abort
Dec 7 11:01:45.574703 osafntfd [464:ntfs_imcnutil.c:0172] TR Imcn
successfully aborted
Dec 7 11:01:45.574712 osafntfd [464:ntfs_imcnutil.c:0187] <<
timedwait_imcn_exit
~~~
---
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