Erlang crash on one node in a bidirectional XDCR set up (uptime 5 days)

Cluster setup: c1:c2::10:10
biXDCR_bucket: c1 <---> c2
uniXDCR_src: c1 ---> c2 :uniXDCR_dest
Front end loads on c1 and c2 for biXDCR_bucket, and on c1 for uniXDCR_src.
c1: http://ec2-177-71-230-72.sa-east-1.compute.amazonaws.com:8091/
c2: http://ec2-175-41-186-167.ap-southeast-1.compute.amazonaws.com:8091/

Erlang crash on one node (c2): ec2-54-251-24-122.ap-southeast-1.compute.amazonaws.com
Erlang core and erl

Access: ssh -i SingaporeQAKey.pem ubuntu@ec2-54-251-24-122.ap-southeast-1.compute.amazonaws.com

ubuntu@ip-10-135-47-251:/opt/couchbase/var/lib/couchbase$ sudo file core
core: ELF 64-bit LSB core file x86-64, version 1 (SYSV), SVR4-style, from '/opt/couchbase/lib/erlang/erts-5.8.5/bin/beam.smp -S 16:16 -sbt u -P 327680 -K'

ubuntu@ip-10-135-47-251:/opt/couchbase/var/lib/couchbase$ sudo gdb /opt/couchbase/lib/erlang/erts-5.8.5/bin/beam.smp core
GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2) 7.4-2012.04
Copyright (C) 2012 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law. Type "show copying"
and "show warranty" for details.
This GDB was configured as "x86_64-linux-gnu".
For bug reporting instructions, please see:
<http://bugs.launchpad.net/gdb-linaro/>...
Reading symbols from /opt/couchbase/lib/erlang/erts-5.8.5/bin/beam.smp...done.
BFD: Warning: /opt/couchbase/var/lib/couchbase/core is truncated: expected core file size >= 1096171520, found: 123731968.
[New LWP 15203]
[New LWP 15207]
[New LWP 15210]
[New LWP 15208]
[New LWP 15205]
[New LWP 15216]
[New LWP 15209]
[New LWP 15215]
[New LWP 15214]
[New LWP 15213]
[New LWP 15217]
[New LWP 15206]
[New LWP 15212]
[New LWP 15211]
[New LWP 15202]
[New LWP 15201]
[New LWP 15204]
[New LWP 15200]
[New LWP 15226]
[New LWP 15197]
[New LWP 15199]
[New LWP 15198]
Cannot access memory at address 0x7f52941962a8
Cannot access memory at address 0x7f52941962a0

(gdb) t a a bt

Thread 22 (LWP 15198):
#0 0x00007f5293441d2d in ?? ()
Cannot access memory at address 0x7f52927f2e40
(gdb) quit

Core: https://s3.amazonaws.com/bugdb/MB--/core.tar
Erl_crash_dump: https://s3.amazonaws.com/bugdb/MB--/erl_crash.dump.tar