Percona XtraDB Cluster 5.6 Memory Leak

Hello! I have Percona XtraDB Cluster 5.6 Ver. 5.6.28-76.1-56 for debian-linux-gnu
A cluster consists of two nodes.
On both servers every day monotonically consumed memory.
Size innodb data of about 50 GB
FLUSH TABLES always cleans about 200 mb. Every day increases the amount of memory consumed by 5-10 GB. Below my.cnf


[client]

port = 3306
socket = /var/run/mysqld/mysqld.sock

default_character_set = utf8

[mysqld_safe]

socket = /var/run/mysqld/mysqld.sock
nice = 0

[mysqld]

tmpdir = /ramdisk/mysql_tmp
tmp_table_size = 10G
max_heap_table_size = 10G

user = mysql
pid-file = /var/run/mysqld/mysqld.pid
socket = /var/run/mysqld/mysqld.sock
port = 3306
basedir = /usr
datadir = /var/lib/mysql
lc-messages-dir = /usr/share/mysql

character-set-server = utf8
collation-server = utf8_unicode_ci
skip-character-set-client-handshake

performance_schema = OFF
innodb_flush_neighbors = 0

skip-external-locking
skip-name-resolve

sql_mode = ""

wsrep_provider = /usr/lib/libgalera_smm.so

binlog_format = ROW

default_storage_engine = InnoDB

innodb_autoinc_lock_mode = 2

wsrep_sst_method = xtrabackup-v2

wsrep_cluster_name = cluster

wsrep_sst_auth = "user:password"

wsrep_slave_threads = 24

net_write_timeout = 600

wsrep_cluster_address = gcomm://.....................

wsrep_node_address = x.x.x.x

key_buffer_size = 32M
max_allowed_packet = 16M
thread_stack = 192K
thread_cache_size = 2049

myisam-recover-options = BACKUP
max_connections = 2048

table_open_cache = 2048
table_definition_cache = 2048

sort_buffer_size = 4M
read_rnd_buffer_size = 2M
read_buffer_size = 2M
join_buffer_size = 16M

#query_cache_limit = 2M
#query_cache_size = 128M
query_cache_type = 0
#query_cache_min_res_unit = 2K

wait_timeout = 300
interactive_timeout = 3600

max-connect-errors = 10000

log_error = /home/webmaster/data/logs/mysql/mysql.error.log

innodb_buffer_pool_size = 128G
innodb_buffer_pool_instances = 12
innodb_additional_mem_pool_size = 32M
innodb_log_file_size = 8G
innodb_log_buffer_size = 64M
innodb_flush_method = O_DIRECT
innodb_flush_log_at_trx_commit = 2

innodb_locks_unsafe_for_binlog = 1

innodb_thread_concurrency = 24

transaction-isolation = READ-COMMITTED

[mysqldump]

quick
quote-names
max_allowed_packet = 16M

[mysql]

[isamchk]
key_buffer = 16M

!includedir /etc/mysql/conf.d/

[sst]

progress=1
time=1


Please help!