MaxScale received fatal signal 11. Attempting backtrace.

Hi,

I have maxscale server installed with version 1.1.1 release 2.

The problem is crashing of maxscale service with the following output:

2015-06-17 12:20:06 Fatal: MaxScale received fatal signal 11. Attempting backtrace.
2015-06-17 12:20:06 /usr/local/mariadb-maxscale/bin/maxscale() [0x54979c]
2015-06-17 12:20:06 /lib64/libpthread.so.0() [0x33b960f710]
2015-06-17 12:20:06 /lib64/libc.so.6() [0x33b92371b2]
2015-06-17 12:20:06 /usr/local/mariadb-maxscale/modules/libmysqlmon.so(+0x26f4) [0x7ff2241eb6f4]
2015-06-17 12:20:06 /usr/local/mariadb-maxscale/modules/libmysqlmon.so(+0x2980) [0x7ff2241eb980]
2015-06-17 12:20:06 /lib64/libpthread.so.0() [0x33b96079d1]
2015-06-17 12:20:06 /lib64/libc.so.6(clone+0x6d) [0x33b92e8b5d]

Earlier it worked fine, just noticed this problem after some permission changes for maxscale user on backend mysql server. Reverting/recreation of user permissions doesn't help.

Also mysql client is installed
Name : mysql
Arch : x86_64
Version : 5.1.73
Release : 3.el6_5

What might be the reason of that?

Maxscale.cnf content

[maxscale]
threads=4
enable_root_user=1

[MySQL Monitor]
type=monitor
module=mysqlmon
servers=zzz
user=zzz
passwd=zzz
monitor_interval=10000

[qla]
type=filter
module=qlafilter
options=/tmp/QueryLog

[fetch]
type=filter
module=regexfilter
match=fetch
replace=select

[Read Connection Router]
type=service
router=readconnroute
servers=zzz
user=zzz
passwd=zzz
router_options=slave

[Debug Interface]
type=service
router=debugcli

[Debug Listener]
type=listener
service=Debug Interface
protocol=telnetd
port=4442

[CLI]
type=service
router=cli

[CLI Listener]
type=listener
service=CLI
protocol=maxscaled
port=6603

[Read Connection Listener]
type=listener
service=Read Connection Router
protocol=MySQLClient
port=3306
socket=/tmp/readconn.sock

[zzz]
type=server
address=<address>
port=3306
protocol=MySQLBackend

Regards
Sergey