Mariadb node2 memory usage high 44% than node1

Hi,
we have galera mariadb cluster, there have 3 nodes , Node1 and Node2 are data provision , Node3 is witness,
Node 1 process and loading heavy than node2, but node2 memory usage high 44% than node1, i want to know the reason? thanks

environment info:
-----------
cpu: 2
memory: 8G
mariadb version is : 10.6.14-1.el7.centos.x86_64
galera version is: 26.4.14-1.el7.centos.x86_64

Node 1 process count: 180
Node 2 process count: 132
--------mariadb.cnf----------
[mariadb]
user = xxxxxx
datadir = /xxxxxx
tmpdir = /xxxxxx
socket = /xxxxxx.socket
pid-file = /xxxxxx.pid
log_error = /xxxxxx/mariadb-error.log
log_warnings = 3
slow_query_log_file = /xxxxxx/mariadb-slow.log
general_log_file = /xxxxxx/mariadb.log
bind-address = xxxxxx-db
port = xxxxxx
ignore-db-dirs = lost+found

character-set-server = xxxxxx
character-set-client-handshake = false

autocommit=OFF
max_allowed_packet = 64M
table_open_cache = 2000
sort_buffer_size = 2M
read_buffer_size = 1M
thread_cache_size = 256
table_open_cache_instances = 8
explicit_defaults_for_timestamp = ON
lower_case_table_names = 1
transaction-isolation = read-committed
large_pages = OFF
thread_handling = one-thread-per-connection
wait_timeout = 3600
log_bin_trust_function_creators = 1

log-bin = /xxxxxx
binlog_format = row
max_binlog_size = 1073741824
expire_logs_days = 3
log_slave_updates = 1
slave_net_timeout = 60

query_cache_type=OFF
query_cache_size=0

max_connections = 500
max_connect_errors=1000000
max_password_errors = 5

default-storage-engine = innodb
innodb_buffer_pool_size = 2048M
innodb_flush_method = O_DIRECT
innodb_flush_log_at_trx_commit = 1
innodb_file_per_table = ON
innodb_data_home_dir = /xxxxxx
innodb_data_file_path = systemts1:1G:autoextend:max:4G
innodb_log_group_home_dir = /xxxxxx
innodb_log_file_size = 200M
innodb_undo_tablespaces = 2
innodb_autoinc_lock_mode = 2
innodb_lock_wait_timeout = 50
innodb_sort_buffer_size=50M
innodb_open_files = 450
innodb_status_output_locks = on
innodb_temp_data_file_path = ibtmp1:512M:autoextend:max:3G

secure_file_priv = /xxxxxx
max_heap_table_size=64M
tmp_table_size=64M

key_buffer_size = 20M
skip_external_locking = ON

innodb_monitor_enable = all
performance_schema = ON

plugin_load_add = auth_ed25519
plugin_load_add = metadata_lock_info

plugin_load_add = server_audit
server_audit_logging = ON
server_audit_events = CONNECT
server_audit_file_rotate_size = 100000000
server_audit_file_rotations = 30
server_audit_output_type = FILE
server_audit_file_path = /xxxxxx/audit

plugin_load_add = simple_password_check
simple_password_check_minimal_length = 8
simple_password_check_digits = 1
simple_password_check_letters_same_case = 1
simple_password_check_other_characters = 1
default_password_lifetime = 60

allow-suspicious-udfs = FALSE
local_infile = OFF
skip-grant-tables = FALSE
skip_symbolic_links = YES
sql_mode = STRICT_ALL_TABLES,STRICT_TRANS_TABLES,ERROR_FOR_DIVISION_BY_ZERO,NO_AUTO_CREATE_USER,NO_ENGINE_SUBSTITUTION

wsrep_on = ON
wsrep_cluster_name = xxxxxx
wsrep_cluster_address = "gcomm://xxxxxx-db:18301,xxxxxx-db:18301,xxxxxx:18301"
wsrep_provider = /usr/lib64/galera-4/libgalera_smm.so
wsrep_provider_options="gmcast.listen_addr=tcp://xx.xx.xx.xx:18301;ist.recv_addr=xxxxxx-db:18302;socket.ssl_cert=/xxxxxx/server-cert.pem;socket.ssl_key=/xxxxxx/server-key.pem;socket.ssl_ca=/xxxxxx/ca-cert.pem;gcs.fc_limit=500;gcache.size=5120M;socket.ssl=yes;socket.ssl_cipher=TLSv1.2,TLSv1.3;gmcast.peer_timeout=PT10S;evs.suspect_timeout=PT12S;"
wsrep_node_name = xxxxxx
wsrep_node_address = xxxxxx:18301
innodb_autoinc_lock_mode = 2
wsrep_slave_threads = 128
wsrep_sst_method = mariabackup
wsrep_sst_auth = xxxxxx:
wsrep_sst_receive_address = xxxxxx:18303
proxy_protocol_networks = xx.xx.xx.xx,yy.yy.yy.yy

ssl
ssl-ca = /xxxxxx/ca-cert.pem
ssl-cert = /xxxxxx/server-cert.pem
ssl-key = /xxxxxx/server-key.pem
tls_version = TLSv1.2,TLSv1.3
ssl_cipher = TLSv1.2,TLSv1.3
extra_port = xxxxxx
extra_max_connections = 10
wsrep_trx_fragment_size = 10485760
wsrep_trx_fragment_unit = bytes
innodb_force_primary_key = ON
wsrep_auto_increment_control = OFF
auto_increment_increment = 3
auto_increment_offset = 1
performance-schema-consumer-events-waits-current = ON
performance-schema-consumer-events-waits-history = ON
performance-schema-consumer-events-waits-history-long = ON
max_user_connections = 480
sync_binlog = 1
innodb_max_dirty_pages_pct = 75
innodb_log_buffer_size = 64M

[client]
port = xxxxxx
socket = /xxxxxx.socket
default-character-set = utf8mb4

[mysqldump]
quick
max_allowed_packet = 64M

[mysql]
no-auto-rehash
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