Hi Praveen, I'm testing/looking through the patch. Thanks, Minh

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** [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:** Wed Dec 14, 2016 11:38 AM 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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