"Too many connections" at maxscale

[adi susanto]

 i have 2 months doing testing using maxscale as my database load balancer mysql galera.
But maxscale always stuck and if maxscale runs normally, the website keeps running slowly.
Sometimes I get the message "Too many connections"
Is there a configuration error that I did.

Following my maxscale configuration.

=====

[maxscale]
threads=4

[Galera Monitor1]
type=monitor
module=galeramon
servers=server1,server2,server3
user=admin
passwd=Password
monitor_interval=10000
disable_master_failback=1

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

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

[RW1]
type=service
router=readwritesplit
servers=server1,server2,server3
user=admin
passwd=Password
max_slave_connections=100%
router_options=slave_selection_criteria=LEAST_CURRENT_OPERATIONS

[RR]
type=service
router=readconnroute
router_options=synced
servers=server1,server2,server3
user=admin
passwd=Password

[DebugInterface]
type=service
router=debugcli

[CLI]
type=service
router=cli

[RWlistener1]
type=listener
service=RW1
protocol=MySQLClient
address=10.20.255.50
port=4010

[RRlistener]
type=listener
service=RR
protocol=MySQLClient
address=10.20.255.50
port=4006

[Debug Listener]
type=listener
service=DebugInterface
protocol=telnetd
address=127.0.0.1
port=4442

[CLI Listener]
type=listener
service=CLI
protocol=maxscaled
socket=default

[server1]
type=server
address=10.20.255.65
port=3306
protocol=MySQLBackend

[server2]
type=server
address=10.20.255.66
port=3306
protocol=MySQLBackend

[server3]
type=server
address=10.20.255.67
port=3306
protocol=MySQLBackend
===========

and this is my maxscale log

===========

2017-05-15 10:24:06   notice : Server changed state: server1[10.10.255.65:3306]: slave_up. [Down] -> [Slave, Synced, Running]

2017-05-15 10:24:06   notice : Server changed state: server2[10.10.255.66:3306]: master_up. [Down] -> [Master, Synced, Running]

2017-05-15 10:24:06   notice : Server changed state: server3[10.10.255.67:3306]: slave_up. [Down] -> [Slave, Synced, Running]

2017-05-15 10:24:34   error  : Invalid authentication message from backend. Error : 08004, Msg : Too many connections

2017-05-15 10:24:34   error  : Backend server didn't accept authentication for user gamebrot_user.

2017-05-15 10:24:38   error  : Invalid authentication message from backend 'server3'. Error code: 1040, Msg : Too many connections

2017-05-15 10:24:39   error  : Invalid authentication message from backend. Error : 08004, Msg : Too many connections

2017-05-15 10:24:39   error  : Backend server didn't accept authentication for user gamebrot_user.

2017-05-15 10:24:39   error  : Invalid authentication message from backend 'server3'. Error code: 1040, Msg : Too many connections

2017-05-15 10:24:43   error  : Invalid authentication message from backend 'server3'. Error code: 1040, Msg : Too many connections

2017-05-15 10:24:43   error  : Invalid authentication message from backend 'server3'. Error code: 1040, Msg : Too many connections

2017-05-15 10:24:45   error  : Invalid authentication message from backend. Error : 08004, Msg : Too many connections

2017-05-15 10:24:45   error  : Backend server didn't accept authentication for user gamebrot_user.

2017-05-15 10:24:45   error  : Invalid authentication message from backend. Error : 08004, Msg : Too many connections

2017-05-15 10:24:45   error  : Backend server didn't accept authentication for user gamebrot_user.

2017-05-15 10:24:48   error  : Invalid authentication message from backend 'server2'. Error code: 1040, Msg : Too many connections

2017-05-15 10:24:48   error  : Invalid authentication message from backend 'server3'. Error code: 1040, Msg : Too many connections

2017-05-15 10:24:48   error  : Invalid authentication message from backend. Error : 08004, Msg : Too many connections

2017-05-15 10:24:48   error  : Backend server didn't accept authentication for user gamebrot_user.

2017-05-15 10:24:48   error  : Invalid authentication message from backend. Error : 08004, Msg : Too many connections

2017-05-15 10:24:48   error  : Backend server didn't accept authentication for user gamebrot_user.

2017-05-15 10:24:49   error  : Failed to obtain address for host 184.vpsio.beon.co.id, Name or service not known

2017-05-15 10:24:49   warning: Failed to add user cm...@184.vpsio.beon.co.id for service [RW1]. This user will be unavailable via MaxScale.

2017-05-15 10:24:51   error  : Failed to obtain address for host jos.clustercontrol, Name or service not known

2017-05-15 10:24:51   warning: Failed to add user cm...@jos.clustercontrol for service [RW1]. This user will be unavailable via MaxScale.

2017-05-15 10:24:51   error  : Failed to obtain address for host *, Name or service not known

2017-05-15 10:24:51   warning: Failed to add user adi@* for service [RW1]. This user will be unavailable via MaxScale.

2017-05-15 10:24:51   notice : Server changed state: server3[10.10.255.67:3306]: slave_down. [Slave, Synced, Running] -> [Down]

2017-05-15 10:24:56   warning: Disabling slave 10.10.255.65:3306, result differs from master's result. Master: 0 Slave: 1

2017-05-15 10:25:13   notice : Server changed state: server1[10.10.255.65:3306]: slave_down. [Slave, Synced, Running] -> [Down]

2017-05-15 10:25:13   notice : Server changed state: server3[10.10.255.67:3306]: slave_up. [Down] -> [Slave, Synced, Running]

==========

please help about this

thank you

Regards

Adi Susanto

[Markus Mäkelä]

Hi,

The "Too many connections" error usually means that you have more clients than is allowed on the backend server. Increasing the value of max_connections should help with that issue.

Can you explain the "maxscale always stuck" part in mode detail? Does MaxScale hang or return an error? If any of these are true, please open a bug report on our Jira and we'll get it fixed.

Markus

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